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P L A N E T A R Y N E B U L A E IN T H E G A L A X Y
P. R. AMNUEL, O. H. GUSEINOV, andYU. S. RUSTAMOV
Institute of Physics, Academy of Sciences, Baku, U.S.S.R.
(Received 19 October, 1988)
Abstract. It is shown that the planetary nebulae can be divided into three types according to the values of the mass of shell and a central star. The criteria are given using which one can determine the mass type of the nebula. The distance scale of each mass-type planetary nebulae is given. The distribution of planetary nebulae in the Galaxy, their formation rate, scale-height and other physical and kinematic characteristics are investigated. A catalogue of planetary nebulae emitting in the radio range is given.
1. Introduction
Planetary nebulae (PNe) represent a very nonuniform group of objects. At the end of
their evolution stars with masses from ~ 0.8 M o to 6-8 M o pass through the PN stage (since PNe are already detected in galactic and globular clusters). It is clear that the difference in parent star masses must have as a result PN property differences as well.
There are both theoretical and observational investigations (Koester and Weidemann, 1980; Weidemann, 1987; Amnuel et aL, 1987) concerning the connection of the parent star mass with that of a remnant which forms after the end of a normal evolution. However, construction of such transitional function leaves aside the problem of mass and other properties of PNe. Therefore, the task of determining the PN parameters knowing at the same time the parameters of parent stars and final products, is important. A converse task of determining, e.g., the parent star mass by the observed PN parameters is also interesting. Another important problem will also be solved: namely, what number of stars generally goes through the PN stage at the end of evolution ?
Many times PNe were divided into several types. Thus, in the works by Greig (1971, 1972), or Zuckerman and Aller (1986) it is shown that PNe having morphological type B differ by kinematic and spatial characteristics from PNe with morphological type C. In the works by Peimbert (1978) and Torres-Peimbert (1985), PNe are divided into 4 types by their chemical composition. It is shown that by other characteristics (morphological type, spectral class of a central star, distribution in the Galaxy, etc.)these 4 types of PNe also differ.
In studying PNe as galactic objects (number, formation rate, spatial distribution) one usually takes them to be, on the average, equal. Particularly, when this or that distance scale is accepted, an average of the chosen main PN parameters is supposed in advance. Thus, Shklovsky's scale and its modifications (Shklovsky, 1956; Cahn and Caler, 1971; Cudworth, 1974; Milne and Aller, 1975; Milne, 1979) suppose that the mass of all PNe (optically thin objects) are equal. Milne's scale (Milne, 1979) being equal for a number of PNe supposes the radio luminosity (objects which are optically thick in Lyman continuum). Accepting the scale (Maciel and Pottasch, 1980; Maciel, 1981; Daub,
Astrophysics and Space Science 154: 21-88, 1989. �9 1989 Kluwer Academic Publishers, Printed in Belgium.
22 P. R. AMNUEL ET AL.
1982; Amnuel et al., 1984) which suggests an eventual transition from optically thick objects to thin ones, equal-size PNe should be equally emitting as well.
To some extent this was due to the small number of PNe whose distances were known. For example, Daub (1982) used only 14 PNe calibrators for constructing the distance scale. In our work (Amnuel et al., 1984) we used 15 calibrators. However, lately there appeared works (Pottasch, 1984; Kaler and Lutz, 1985; Maciel et al., 1986; Gathier et al., 1986a, b; Sabbadin, 1986a; Weinberger and Zeiner, 1988) in which independent distance estimates of a large number of PNe have been given. This allowed us to estimate the statistical importance of the used distance scales. Such estimates were given, e.g., by Sabbadin and Gathier (Sabbadin, 1986b; Gathier, 1987) who came to the conclusion that all statistical distance scales give, on average, wrong values. Sabbadin (1986b) showed that our scale (Amnuel et al., 1984) determines distances to PNe of morphological class C well and 1.5 times lessens distances to class B PNe. At the same time, according to Ishida and Weinberger (1987), one must diminish the distances in order to bring together the data on the nearest PN observations with our distance scale.
As a calibration dependence for determining PN distances we accepted (Amnuel et al., 1984) - and will accept - below the correlation between the value of PN surface brightness in radio range 2 = a(S/O 2) (where S is the radio emission intensity at some frequency, 0 is the measured mean angular diameter of PN radio image) and its
diameter D. In order to determine E and D, the following observational data are necessary: (1) PN radio emission intensity at some frequency S~, at which PN is optically thin. (2) PN angular sizes 0. (3) Independent PN distance measurements. (4) Criteria allowing to divide the PNe into several classes. At present, radio emission
intensities of ~ 350 PNe are measured; moreover, in many cases the measurements were carried out at several frequencies. It follows from observations that practically all PNe are optically thin at 5 GHz. We used the data obtained at this very frequency to determine 12.
The problem of the PNe angular sizes is more complex. Many PNe are not spherical; this adds uncertainty to the value of 0. Besides, the value of 0 often depends on the exposition time (in case of photo observations). Cases when PN radio image poorly agrees with optical ones are known. Besides, a number of PNe have a so-called 'halo' which also represents an ionized matter. Knowing all difficulties due to 0, we shall hereafter take as 0 the value determined by optical observations. In those cases when the values of 0 determined by different authors slightly differ from each other, we shall use the mean values of 0 for a given PN.
A knowledge of the distance scale of different classes of PNe will allow in principle to answer a number of important questions on the origin of PNe, their number and distribution in the Galaxy, possible way of PN evolution. In what follows we shall try to present a statistical distance scale of each class of PNe dividing them into several classes. Then if we know the PN distances, we shall be able to give their distribution
PLANETARY NEBULAE IN THE GALAXY 23
in the Galaxy, their formation rate, to find out the connection of various type PNe with parent stars, to determine though roughly the mass distribution of PN central stars, and to try also to answer the question which is important for understanding the PN evolution, viz., which of the matter ejection models is realised during a PN formation .9
In Section 2 the methods of determining distances of the PNE are given and PNe with the most reliably measured distances are pointed out. In Section 3 the criteria allowing to divide all PNe at least into 3 classes are considered in detail and the respective division of PNe into classes is made. Section 4 deals with distance scales of low-mass PNe, their masses, mean filing factors, distribution in the Galaxy, birthrate and other physical parameters are determined. In Sections 5-7 similar parameters are, respectively, determined for massive, middle mass PNe as well as for those ones which we selected from massive and middle-mass PNe and called them anomalous.
It should be noted that we considered only those PNe for which existing radio observations give a concrete value of radio flux at 5 GHz, and not the value of the upper limit. The same can be said about the values of angular diameter 0.
2. Methods of Determining Distances of the PNe's
Various methods of determining distances d of the PNe's were many times discussed in the works by Pottasch (1984), Sabbadin (1986b), etc. These papers give a list of data on independent PN distance determinations. Let us consider briefly main methods of PN distance determinations:
(1) One of the most reliable methods is that by which distances are determined from a spectroscopic parallax of a normal component, if PN central star (CS of PN) is a binary system. The method of determining distance d to PNe belonging to open or globular clusters or other galaxies is the analogous. Now there are good observations of PNe in Magellanic Clouds allowing in principle to find for these PNe the values of Z. However, Magellanic Clouds PNe differ from the galactic ones by chemical composi- tion (Aller et al., 1987); in particular, and therefore, we shall not use extragalactic PNe as calibrators.
(2) The determination of d by means of comparing the PN expansion velocity in the image plane A0 with the radial expansion velocity Vexp. This method is applicable in cases when the PNe possess a nearly-spherical symmetry (morphological type C). For asymmetric PNe (type B) this method may give wrong values of d.
(3) The distance is determined by measuring interstellar absorption in the direction of a PN. Lately the method has been widely used. One should, however, bear in mind that this method is applicable only if the measured absorption value is not due to the immediate medium of PNe - the absorption must take place along the whole distance d. Nowadays, there are data that in some cases absorption really takes place in the PN media (Pottasch, 1984). Nevertheless, we hold that this method is one of the most reliable. By quality the determination of d by radio data using the information on the situation of galactic arms and H II regions in the PN direction.
(4) The value o fd is determined by comparing the measured absorption to PN with
24 P. R. AMNUEL ET AL,
the value of mean absorption in the given direction. In fact, this is a undervariant of
method 3. (5) The value of d is determined by the data on VLsR of PNe from the comparison
with the expected distribution of VLSR by the rotation curve of the Galaxy (both by optical and radio observations).
(6) To estimate the value of d, theoretical models in which d is as a parameter are used. It can be the models of a CS, stellar wind, or PN itself.
A group of methods from 1 to 3 gives more accurate and reliable values of distances than the one from 4 to 6. Therefore, hereafter we shall give the group 1-3 weight coefficient 2 and group 4-6 coefficient 1 (use the method 2 for asymmetric PNe is estimated by 1). For each group concrete PN distances could be determined by several independent methods. Naturally, if the values of d determined by various methods not prove to be contradictory, then weight coefficient of determining d increases. Table IV where all known independent PN distances are listed, shows the weight coefficient which is a sum of individual weight coefficients. The number of methods using which the distance d was determined, is given in brackets. Most reliable is the determination of d to PNe P K 1 0 6 - 1 7 ~ P K 1 0 7 + 2 ~ P K 1 3 0 + I ~ P K 2 1 5 + 3 ~ PK 272 + 12 ~ 1, where the weight coefficient is equal to 5(3). Least reliably d is deter- mined for 39 PNe (e.g., PK 1 - 6 ~ 1, PK 8 + 3 ~ 1) weight coefficient is equal to 1. Distances are determined for 91 PNe, weight coefficients are distributed in the following
way:
Weight PN number Weight PN number
5 (3) 5 3 (3) 1 5(4) 1 2(1) 11 4(2) 1 2(2) 7 4(3) 5 1 38 3 (2) 22
It is, evidently, desirable to use PNe only with the most reliable and most accurate distance determinations and the most reliable determined class of mass as calibrators when constructing a Y{D)-dependence. Thus, as potential calibrators, one can consider 53 PNe whose d is determined with reliability more than 1.
3. PN Mass Criteria
Dividing PNe into several classes, we merely assumed that the evolution of more massive Main-Sequence stars leads to the formation of more massive final products - CS or PN. We suppose that the forming PNe differ by a number of features depending on initial masses of the Main-Sequence stars.
The majority of the mass criteria given below were considered earlier as well. We tried to systematize these criteria and use them for determining mass class of the largest number possible of PNe. Mass criteria can in their turn be divided into types:
PLANETARY NEBULAE IN THE GALAXY 25
(1) criteria determined by PN CS features; (2) criteria determined by parent star features;
(3) criteria determined by features of the PN itself; (4) mixed criteria. As the f i r s t cr i ter ion we use the value of PN CS mass. Determination of PN CS mass
is very difficult. Most reliably and most often used for determining CS mass is the so-called L - T diagram. Without dwelling on the difficulties of choosing this or that evolutionary track we should note that the main error in determining the mass M is due to the observational parameters: CS temperature T and brightness, value of interstellar absorption, etc. In order to determine CS mass we choose only those objects with independent determinations of d (see Section 2). CS temperatures T~er are derived directly from observations of energy distribution in spectra, The data used in determining luminosity L, the obtained values of CS masses M, the used references are given in Table I. Evolutionary tracks from the works by Paczyfiski (1971), Sch0nberner (1979, 1981), Wood and Faulkner (1986) are used. A considerable number of CS are situated in the L - T diagram within the range of masses less than 0.546 M o (the track for this
mass is taken from Sch0nberner, 1981). Partly, it can be due to the errors in determining T and L, however, there are works which theoretically prove the presence of less massive CS (Harpaz and Kovetz, 1987). There are also observational confirmations of the
existence of low-mass CS and white dwarfs (see, e.g., Amnuel e t al. , 1987). By the first criterion we divided PNe into three classes:
- M a s s i v e ones with the mass of the CS, M > 0.64 M o (M-type);
- L o w m a s s ones, M < 0.57 M o (L-type); - I n t e r m e d i a t e m a s s having 0.57 M o < M < 0.64 M o (I-type). According to Amnuel e t al. (1987), CS masses can be connected with those of parent
stars on the Main Sequence. The above-given division of CS by their masses cor- responds to the respectively division of parent stars: massive as those for which Mm, > 3 Mo, low-mass with Mm, < 2 M o, and medium with intermediate masses. As is seen from Table I which gives the masses of 36 CS, 7 of them are M-type, 7 are I-type,
and 22 are L-type. In Table III where all values mass criteria are given the class of massive PNe (M-type)
by some criterion is marked by + 1, that of low-mass PNe (L-type) is marked with - 1, and that of intermediate mass PNe with 0.
Of course, all values of mass indices by any criteria given hereafter are estimates, and in a number of cases they can change at the improved observational material.
The s e c o n d cr i ter ion includes the data on Zanstra temperatures of CSs by hydrogen and helium: Tz(H I) and Tz(Hen). The Zanstra temperatures of a CS are determined by its mass and the state of its evolution as well as the characteristics of the PN. As is seen from Figure i, evolutionary tracks of massive CS are mostly situated in the region of more than 105 K (massive CS has Teef< 105 K during a short period of time at the initial stage of evolution). The CS with T~fr < 105 K, on the contrary, to be low-mass with greater probability can be considered. In the PN features there are differences due to the fact that the L- and M-type nebulae become optically thin for Lyman emission
TA
BL
E
I
No.
P
N n
ame
PN
nam
e lo
g T~
n.
d V
B
E
(B -
V)
log
(L/L
o)
MJ
M e
Ref
eren
ces
PK
(p
c)
1 2
3 4
5 6
7 8
9 10
11
1 2
34
+
2~
NG
C 2
440
5.30
22
00
14.1
5 15
.20
0.31
4.
49
1.10
2
120
+ 9
~ 1
NG
C 4
0 4.
95
(700
) 11
.70
11.6
1 0.
46
3.92
0.
65
3 3
09
- 4
~
NG
C 5
315
4.84
26
00
13.3
8 -
0.38
3.
91
0.64
4
35
8-
0~
M 1
-26
4.52
18
00
12.1
9 12
.98
0.92
3.
85
0.62
5
9-
5 ~
1 N
GC
662
9 4.
71
1500
12
.87
13.0
5 0.
62
3.62
0.
58
6 2
94
+4
3~
N
GC
436
1 4.
96
(140
0)
13.2
1 12
.82
0.13
3.
52
0.58
7
307
- 3
~ 1
NG
C 5
189
4.90
15
00
14.2
14
.17
0.49
3.
47
0.56
8
118
- 74
~ 1
NG
C 2
46
5.08
57
0 11
.94
11.6
3 0.
02
3.38
0.
58
9 31
8 +
41 ~
1 A
36
4.90
50
0 11
.46
11.2
2 0.
30
3.38
0.
56
10
25 -
17
~ 1
NG
C 6
818
(5.0
0)
(220
0)
14.9
-
0.20
3.
37
0.56
11
93
+
5 ~
N
GC
700
8 (4
.84)
10
00
13.2
5 13
.52
0.55
3.
36
0.56
12
37
- 34
~ 1
NG
C 7
009
4.94
(6
00)
11.5
11
.04
0.08
3.
36
0.56
13
65
- 2
7 ~
1 K
648
4.
54
1000
0 14
.95
14.7
6 0.
12
3.33
0.
56
14
34
5-
8~
TC
1
4.50
(1
600)
11
.19
11.1
1 0.
25
3.33
0.
56
15
327
+ 10
~ 1
NG
C 5
882
4.78
(1
100)
12
.65
11.8
4 0.
28
3.32
0.
56
16
19
6-
10~
NG
C 2
022
(5.0
0)
(150
0)
15.1
15
.0
0.32
3.
14
0.56
17
2
06
-40
~
NG
C 1
535
4.71
(1
500)
12
.23
11.9
4 0.
05
3.12
0.
55
18
22
0-5
3~
N
GC
136
0 4.
87
(550
) 11
.32
11.0
0 0.
09
3.12
0.
55
19
281
- 5
~ 1
IC 2
501
4.78
(1
400)
14
.03
- 0.
36
2.90
0.
546
20
197+
17~
N
GC
239
2 4.
58
700
10.4
8 10
,33
0.12
2.
90
0.54
6 21
1
06
- 17
~ N
GC
766
2 4.
90
600
12.5
0 12
.26
0.12
2.
85
0.54
6 22
1
30
- 10
~ N
GC
650
(5
.18)
(1
200)
16
.39
16.0
8 0.
15
2.73
0.
64
23
166
+ 10
~ 1
IC 2
149
4.48
(9
00)
11.3
4 11
.20
0.24
2.
69
0.54
6 24
26
1 +
32 ~
1 N
GC
324
2 4.
87
500
12.3
3 11
.83
0.09
2.
69
0.54
6 25
3
15
- 13
~ H
e 2-
131
4.41
80
0 10
.56
10.4
8 0.
16
2.62
0.
546
26
1-
6~
Sw
St
1 4.
48
1100
0)
11.8
-
0.26
2.
58
0.54
6 27
33
-
6 ~
1 N
GC
677
2 (5
.10)
(1
400)
18
.9
18.5
5 0.
70
2.46
0.
61
28
63 +
13
~ 1
NG
C 6
720
(5.1
1)
550
14.8
14
.5
0.09
2.
42
0.63
1-6
5,
7-1
0
5, 1
1-13
5,
14,
15
1-3,
5,
12-1
6 1,
5,
13,
15-2
0 5,
7,
9, 1
1, 2
1, 2
2 1,
5,
7, 9
, 10
, 12
, 20
, 23
1,
5,
12,
13,
16,
19,
23
2, 5
, 14
, 19
, 24
1,
2,
5, 9
, 10
, 12
, 14
, 23
5,
9,
12,
15
25,
26
5, 1
5,27
1,
5,
13,
16
1, 5
, 7,
19
1, 5
, 7,
12,
15,
17,
19,
28
1, 2
, 5,
7,
12-1
6, 2
0, 2
9, 3
0 5,
9,
31
1, 2
, 5,
7,
9, 1
0, 1
2, 1
5, 1
9 I,
2,
5, 7
, 9,
10,
12
1, 2
, 5,
14,
19,
30
1, 2
, 5
,7,
12,
14
1, 7
, 9,
10,
12-
15,
19,
32
5, 1
0-13
, 16
, 33
, 34
5,
35,
36
1, 1
9,22
1,
9,
10,
14,
19
Tab
le I
(co
ntin
ued)
No.
P
N n
ame
PN
nam
e lo
gTee
r d
V
B
E(B
- V
) lo
g(L
/Lo
) M
c/M
o
Ref
eren
ces
PK
(p
c)
1 2
3 4
5 6
7 8
9 10
II
29
215-
24~
IC
418
4.54
(3
30)
9.97
9.
94
0.18
2.
42
0.54
6 1,
2,
7, 1
2-16
30
29
- 5~
N
GC
6751
4.
41
1500
13
.43
13.7
3 0.
47
2.41
0.
546
1, 2
, 5,
13,
14,
16
31
54-
12~
NG
C68
91
4.66
(6
50)
12.4
1 12
.18
0.17
2.
37
0.54
6 2,
7,
10,
12-1
6, 1
9 32
34
+ 1
1~
NG
C 6
572
4.76
50
0 12
.7
- 0.
27
2.36
0.
546
1, 5
, 7,
13,
16
33
189
+ 19
~ 1
NG
C 2
371
5.00
(5
00)
14.7
8 14
.64
0.12
2.
03
0.59
5,
10,
12,
14
34
60-
3~
NG
C68
53
5.09
25
0 13
.94
13.6
6 0.
05
1.93
0.
71
1, 5
, 7,
12,
14,
19
35
148+
57~
NG
C 3
687
5.07
(4
60)
15.8
8 15
.69
0.05
1.
63
0.85
1,
5,
7, 1
2, 1
4, 1
9, 3
7 36
36
-57~
N
GC
729
3 4.
99
(100
) 11
.90
12.9
7 0.
02
1.05
0.
90
1, 5
, 7,
12,
14,
19
PN
are
dis
trib
uted
acc
ordi
ng t
o le
ssin
ing
ofl
og
L/L
e .
Dat
a in
col
umns
4 a
nd 5
loc
aliz
ed i
n br
acke
ts d
esig
nate
unr
eali
zed
mea
sure
men
ts (
dist
ance
s d
wit
h in
dex
1 ).
Ref
eren
ces
to T
able
I:
h S
abba
din
(198
6a).
14
. C
ahn
(198
4).
27.
Feib
elm
an (
1983
).
2.
Shaw
and
Kal
er (
1985
).
15.
Men
dez
eta
l. (
1988
).
28.
Sab
badi
n et
al.
(198
4).
3. G
athi
er e
tal.
(1
986)
. 16
. L
anda
berr
y et
al.
(198
6).
29.
Ack
er (
1983
).
4. B
arke
r (1
985)
. 17
. A
dam
and
K6p
pen
(198
5).
30.
Kal
er (
1983
).
5. A
cker
et
aL (
1983
).
18.
Men
dez
et a
l. (1
985)
. 31
. G
ohar
ji a
nd A
dam
s (1
984)
. 6.
H
eap
(198
7).
19.
SchO
nber
ner
(198
4).
32.
Ros
ado
(198
6).
7. P
hill
ips
(198
4).
20.
Kal
er (
1981
).
33.
Kal
er e
t al
. (1
985)
. 8.
Bia
nchi
and
Gre
win
g (1
985)
. 21
. Jo
hnso
n (1
981)
. 34
. Su
rdej
et
al.
(198
2).
9. A
cker
(19
78).
22
. R
eay
etal
. (1
984)
. 35
. D
ufou
r (1
984)
. 10
. Po
ttas
ch (
1980
).
23.
Kal
er a
nd F
eibe
hnan
(19
85).
36
. Pa
ehee
o an
d V
eliz
(19
87),
11
. G
athi
er e
t al.
(198
6).
24.
Sab
badi
n (1
984)
. 37
. S
abba
din
et a
l. (1
985)
. 12
. Po
ttas
ch (
1984
).
25.
Ada
ms
et a
L (
1984
).
13.
Pach
eco
et a
L (
1986
).
26.
Gat
hier
et
al.
(198
3).
28 P. R, AMNUEL ET AL,
I I I
1.20
@1 0.89
0.6
0.60
0.57
0.70
0.546
5.5 5 .o 4.5 4.0 log T
Fig. 1. The dependence ofbolometric luminosity L/L o on the effective temperature T of the central stars with independent temperatures and distances. The evolutionary tracks of the CS with masses from 0.546 M o
to 1.2 M o are given. The numbers of the CS are given in accordance with Table I.
at different stages of evolution. This circumstance requires a subdivision of the PNe into massive and low-mass when using the Zanstra temperatures. The PN temperature mass criterion is approximate but its advantage is in that it is not dependent on PN distance.
We established the quantitative boundaries of the second criterion using the data ,of Table I. Thus, two-thirds of the L-type PNe by first criterion have Tz(H 0 < 40000 K and Tz(Hen) < 9 x 10 4 K. Two-thirds of the M-type PNe by the first criterion have Tz(H1 ) = T~(Heu) > 1.15 x 105 K. Using Tz(H 0 as the temperature criterion is more justified, but we made use of the value of T~ (He n) also to be more certain.
Mass classes of 124 PNe are determined by the second criterion. The data are given in Table III.
Our third criterion shows the dependence of PN chemical composition on the mass of parent star. Just like the second criterion it is not dependent on the PN distance. The quantity of many chemical elements, such as He, N in the first place, is determined by nuclear reactions which had taken place within the parent star.
Data on the chemical composition of 128 PNe are given in Table II. Analysis of these
PLANETARY NEBULAE IN THE GALAXY
TABLE II
29
PK name log(He/H) logN logO log(N/O) logC logNe logAr logs
1 2 3 4 5 6 7 8 9
0+ 12~ -0.988(2) 7.10 8.54(2) - 1.44 8.13 8.00 6.15 6.60 1 - 6~ 7.61 8.54 - 0.93 8.28 6.48 2+ 5~ -0,88 8.08 8.46 -0.38 7.61 6.62 6.78 2 - 2~ - 1.10 -0.50 2 - 13 ~ 1 - 1.071 7.89 8.82 -0.93 8.05 6.35 7.12 2 - 4~ - 0,77 8.91 8.67 +.024 8.13 6.66 7.28 2 - 6 ~ 1 - 1.03 7.60 8.62 - 0.98 7.90 6.42 6.46 3 + 2 ~ 1 - 0,90 8,45 8.68 - 0.23 7,96 6.50 7.29 3 - 2~ -0 .84 8.45 8.72 -0.27 8.15 6.9 7.26 5 - 6~ -0.94 8.65 8.84 -0.19 8.18 6.6 7,1 6+ 4~ -0.90 8.7 8.52 +0,18 7.69 6.30 7.01 6+ 4~ -0.97 8.08 8.41 -0.33 7.48 6.5 6.7 7+ 1~ -0.96 8.65 8.71 -0.06 8.00 6.70 7.30 8+ 3~ -0.66(4) 8.23(2) 8.38(3) -0.15 7.82 8 - 7~ -0.851(2) 8.00 8,57(2) -0.57 7.76 9+ 14~ -0.879(5) 8.00(4) 7.81(5) -0.81 9.10(2) 8.09(2) 6.76 7.52 9 - 5~ - 1.06 7.76 8.60 -0.84 7.77 6,6 6.55
10 + 18~ - 1.097 7.61 8.41 - 0.80 8.48 10 + 0 ~ 1 - 0.62 8.46 8.20 + 0.26 10- 1~ -1.018 8.29 8.84 -0.55 10- 6~ -0.97 7.94 8,42 -0.48 7.71 5.98 6.79 11+ 5~ -0.87 8.46 8.65 -0.19 8.06 6.45 7.15 11- 0~ -0.928(2) 7.98 8,48 -0.50 2 5 - 17~ -0.939(6) 8.18(5) 8,67(6) -0.49 8.67(4) 8.10(5) 6.56(4) 6.99(4) 25 + 40 ~ 1 - 0.943 (5) 7.13 (4) 8,46 (4) - 1.33 8.96 (2) 7.81 (2) 6,35 (2) 7.11 (4) 2 7 - 9~ -1.032(3) 7.78(3) 8,61(4) -0.83 9.00 7.89(2) 6.09 6.82 2 9 - 5~ - 1.009(5) 8.26(4) 8,68(4) -0.42 7.86(2) 7.28(2) 6.56(3) 3 3 - 2~ -0.896(4) 8.54(4) 8.71(5) -0.17 9.02(2) 8.13(4) 6.62(3) 7.09(4) 34+11~ - 0.914(5) 8.17(6) 8.69(6) -0.52 8.78(4) 8.08(3) 6.41(2) 6.84(4) 3 4 - 6~ - 0.788(4) 8.57(3) 8.58(4) -0.01 9.00 8.23(2) 6.43 7.18 36 - 57 ~ 1 - 0.745 (2) 8.4 ? 8.52 - 0.12 8.41 6.00 3 7 - 6~ -0.917(7) 7,94(6) 8.57(7) -0.63 8.77(5) 7.85(4) 6.18(3) 6.88(5) 37 -34~ -0.951(8) 8,31(8) 8.67(8) -0,36 8.77(6) 8.10(6) 6.48(4) 7,10(5) 38 + 12 ~ 1 - 1.4 ? 8.03 (2) 8.52 (2) - 0.49 8.70 7.93 6.4 4 1 - 2~ -0.89 8.35 8.64 -0.29 7.83 6.60 7.00 4 2 - 6~ -0.91 7.92 8.56 -0.64 7.88 6.78 6.97 43 + 37 ~ 1 - 0.966(6) 7,70(4) 8.62(5) - 0,92 8.86(2) 7.88(3) 6.29(2) 7.35(4) 4 5 - 4~ -0,86 8.50 7.7 5.6 4 6 - 4~ -0.886(4) 8.49(3) 8.70(4) -0,21 8.73 8.33(3) 6,84(2) 7.12(2) 51 + 9 ~ 1 - 1.032(5) 7.54(4) 8.40(4) - 0.86 8.72(3) 7,48(2) 5,99(2) 6.21 (3) 5 2 - 2~ -0,90 8,60 8.74 -0.14 8.15 6.81 7.11 54 - 12 ~ 1 - 0.940 7.61 8.40 (3) - 0.79 8.67 7.75 57 - 8 ~ 1 - 0.98 7.89 8.61 - 0.72 7.95 6.28 6.60 58 - 10 ~ 1 - 0.920 8.06? 8.56 - 0.50? 8.219. 8.25 7,41 60 - 3 ~ 1 - 0.917(4) 8.52(5) 8.89(5) - 0.37 8.81 (3) 8.39(4) 6.52(2) 6.70(3) 60 - 7 ~ 1 - 0.92 - 0.80 6 0 - 7~ -0.833(3) 8 , 3 3 8.65(3) -0.34 8.81 8,21(3) 6.45(2) 7.24(3)
30
Table II (continued)
P. R. AMNUEL ET AL.
PK name log (He/H) log N log O log (N/O) log C log Ne log Ar log S
1 2 3 4 5 6 7 8 9
61 - 9 ~ 1 - 0.979 8.00 8.66 - 0.66 8.65 8.15 6.46 7.00 63 + 13 ~ 1 - 0.920 (7) 8,31 (3) 8.77(5) - 0.46 8.75 (5) 8,09 (3) 6.50 (3) 7.00 64 + 48 ~ 1 - 0.752 8.05 8.54 - 0.49 7,00 64+ 5~ - 1.4 8.13(2) 8,57(2) -0 .54 8.73 7.20 6 5 - 2 7 ~ -0.975(2) 6.95(4) 7.68(3) -0.73 8.73 6.60(3) 5.15 6 9 - 2~ -1.000 8.58 8.69 -0.11 7 1 - 2~ - 1.000 -0 .50 74+ 2~ -0.873(2) 8.46 8.64(2) -0 .18 8.04(2) 6.78 82 + 11 ~ 1 - 1.046 7.20 7.92 - 0.72 82+ 7~ -0.917(4) 7.86(4) 8.66(3) -0 .80 8.93(3) 7.99(5) 6.57(4) 7.05(5) 83+ 12~ -0.959(6) 7.60(6) 8.43(5) -0.83 9.13(4) 7.92(3) 6.07(2) 6.50(3) 8 4 - 3~ -0.947(4) 8.34(4) 8.66(3) -0 .32 9.05(3) 7.87(2) 7.12 7.00(2) 8 6 - 8~ -0.785(2) 8.45(4) 8.05(2) +0.40 8.06(2) 7.83(2) 6.20(2) 6.48(2) 89+ 0~ -0.917(7) 8.34(7) 8.71(6) -0 .37 9.03(3) 8.23(4) 6.64(3) 7.40(4) 8 9 - 5~ -0.947(5) 8.04(5) 8.61(5) -0 .57 8.90(3) 8.01(5) 6.38(3) 7.08(3) 93+ 5~ -0.793(3) 8.20 8.20 0 7.76 93+ 1~ - 1,020 7.74 8.07 -0 .33 6.15 6,40 96+29~ - 0.947(5) 8.12(7) 8.72(6) -0 .60 8,91(6) 8.08(3) 6.40(2) 7.13(6)
100- 5~ -0.966(6) 8.03(5) 8 .62(4 ) -0 ,59 8,75(3) 7.94(4) 6.34(3) 7.10(4) 100- 8~ -0.80 8.52 8.22 +0,30 106- 17~ -0.955(6) 7.94(7) 8.57(6) -0.63 8.75(5) 7.81(5) 6.32(4) 6.93(5) 107+ 2~ -0.906(2) 7.64 8.53 -0 .89 111- 2~ -0.979(2) 7.54(2) 8.40(2) -0 .86 8.72(3) 7.59 7.43(2) 119- 6~ -0.959(2) 7.99(2) 8.73 -0 .74 7.96 6.26 7.13 120+ 9~ - 1.155 8.12(4) 8.80(3) -0 .68 8.88 6.61 123 + 34 ~ 1 - 0.966 (4) 7.60 (5) 8.52 (4) - 0.92 8.44 (2) 7.87 (2) 7.06 (3) 130+ 1~ -0.917(6) 8.24(7) 8.67(6) -0.43 9.00(3) 8.04(4) 6.34(3) 6.92(4) 130- 10~ -0,886(5) 8.43(5) 8.72(3) -0 .29 9.08 8.39(3) 6.51 7.26 130- 11~ -0.943(3) 8.06(4) 8.25(3) -0 ,19 8.82 8.00(2) 6.5? 6.76 147- 2~ -1.081 8.33 8.71(2) -0.38 148 + 57 ~ 1 - 1.009 (5) 8.02 (3) 8.58 - 0.56 6.30 159- 15~ -0.996(6) 7,74(5) 8.56(7) -0 .82 9.06(3) 7,86(4) 6.39(3) 6.88(4) 161 - 14 ~ 1 - 0.979 (5) 7.94 (7) 8.56 (7) - 0.62 8.78 (3) 7.79 (4) 6.21 (3) 6.53 (4) 166 + 10~ - 1.018(2) 7.31 (2) 8.32(3) - 1.01 8.34 7.51 6.60 178- 2 - 1.01 7.56 8.12 - 0.56 7.60 6.30 184- 2~ -1.046 7.56 8.66 -1 .10 189+19~ -0.928(6) 8.33(7) 8.70(5) -0 .37 8.89(3) 8.22(2) 6.65(2) 7.04(3) 189+ 7~ -0.991 8.52(3) 8.71(2) -0 .19 7.90 6.10 6.69 190- 17~ -0906(5) 7.57(5) 8.24(5) -0 .67 8.64(2) 7.67(2) 6.14 6.72(2) 194+ 2~ -0.971(5) 7.69(5) 8.47(5) -0 .78 9.03(3) 7.84(4) 5.99(3) 6.51(4) 196- 10~ -0.936(4) 7.96(3) 8.54(3) -0 .58 8.53(2) 7.88(2) 6.52 7.50 197 + 17 ~ 1 - 0.996(3) 8.26(4) 8.52(3) - 0.26 8.30(2) 7.70(2) 6.08 6.72(2) 205 + 14 ~ 1 - 1.027 8.36(6) 8.48(6) - 0.12 8.30(6) 6.86(6) 206-40~ -0,966(6) 7.38(5) 8.56(6) - 1.18 8.80(3) 7.94(3) 6.38(2) 212 + 4 ~ 1 - 0.721 7.75 7.49 + 0.26 6.46 215+ 3~ -0.833(3) 8.10(2) 8.33(2) -0.23 7.82(2) 6.5 6.2 215 - 24 ~ 1 - 0.983(5) 7.82(7) 8.58(6) - 0,76 8,80 (4) 7.84(3) 6.32(3) 6.66(4) 221 - 12 ~ 1 - 0.943(6) 8,02(7) 8.49(6) - 0.47 9,00(3) 7.91 (5) 6.37(4) 6.79 (5)
PLANETARY NEBULAE IN THE GALAXY 31
Table H (continued)
PK name log(He/H) logN logO log(N/O) logC logNe logAr logS
1 2 3 4 5 6 7 8 9
231+ 4~ - 0.996(2) -0.59 234+ 2~ -0.821(3) 8.77(3) 8.65(2) +0.12 8.50(3) 8.02(2) 6.62(2) 6.58(2) 243- 1~ -0.947(5) 8.55(3) 8.56(3) -0.01 9.06 7.81(2) 6.54 6.98 261 +32~ - 1.000(8) 7.94(8) 8.64(7) -0.70 8.45(5) 7.92(7) 6.26(6) 6.69(7) 261 + 8~ -0.785 8.59(3) 8.55(2) +0.04 8.23(2) 8.00(2) 6.47(2) 7.21(2) 272+ 12~ -0.892(2) 8.50(2) 8.85 -0.35 275 - 4 ~ 1 - 0.854 7.90 8.50 - 0.60 278+ 5~ -0.721 +0.2 278- 5~ -0.917(2) 8.04(2) 8.63(2) -0.59 8.81 7.96(3) 6.30(2) 6.83(2) 281- 5~ -0.949(4) 8.19(5) 8.80(4) -0.61 8.83(3) 8.19 6.73(2) 285- 14~ -0.987(2) 7.60(2) 8.50(2) -0.90 8.61 7.75(2) 286 - 4 ~ 1 - 0.873 (3) 7.94 8.70 - 0.76 294 + 43 ~ 1 - 0.900 (4) 7.66 (3) 8.35 (3) - 0.69 7.52 (2) 7.72 (3) 6.47 (2) 7.20 294 + 4 ~ 1 - 0.959 (3) 8.24(4) 8.84(2) - 0.60 9.01 (2) 8.10 6.80 309 - 4~ - 0.863 (3) 8.54(3) 8.66(2) - 0.12 9.05 (2) 8.22(2) 7.15 312+ 10~ - 1.000 -0.60 315 - 13~ - 1.495 7.18 8.43 - 1.25 7.91 7.70 6.30 6.74 316+ 8~ - 1.000 -0.50 319+ 1501 -0.854(2) -0.46 327 + 10 ~ 1 - 0.928 (2) 8.06 8.68 - 0.62 7.04 331- 1~ - 0.744 7.60 8.00 -0,40 6.00 334- 9~ 7.61 8.43 -0.82 8.21 8.04 341 + 5~ -0.888 9.30 9.00 +0,30 8.90 8.40 7.00 7.57 342+ 17~ -0.987(2) 8.21(2) 8.73(2) -0.52 8.78(2) 8.17(3) 6.41(3) 7.14(3) 349+ 1~ -0.703(3) 8.73(4) 8.73(4) 0 8.02(2) 8.01(2) 6.97(2) 6.81(2) 353+ 6~ - 1.02 7.68 8.56 -0.88 7.77 6.25 6.7 354+ 4~ - 1.01 8.43 8.73 -0.30 8.08 6.4 6.3 356- 4~ - 1.00 8.66 9.22 -0.56 8.58 6.77 7.51 357+ 7~ - 1.02 8.26 8.68 -0.42 7.92 6.20 7.04 357 + 2~ - 0.76 8.96 8.71 + 0,25 8.08 6.92 7.09 357+ 1~ -0.85 8.58 8.76 -0,18 7.93 6.74 6.98 358- 7~ 8.89 8.78 +0.11 359- 0~ 8.88 8.80 +0.08 8.80 8.06 7.00 7.21
References to Table H:
Acker (1980); Adam and K6ppen (1985); Adams et al. (1984); Aller (1982); Aller and Czyzak (1983); AUer and Keyes (1987); Aller et al. (1985, 1987); Barker (1983); Barker (1984, 1985); Barker and Cudworth (1984); Beck and Lacy (1981); Bianchini et al. (1986); Cohen et al. (1978); Dinerstein (1980); Dufour (1984); Faundez-Abans and Maciel (1986); Feibelman (1984); Flower (1982); French (1983); Gathier et al. (1986); Ooharji and Adams (1984); Golovaty et al. (1979); Hua and Grundseth (1985); Kaler (1983a, b, 1984); Kaler and Hartkopf (1981); Kwitter et aL (1983); Lutz (1984); Pottasch (1984); Pottasch et al. (1986); Pwa et al. (1984); Sabbadin (1986a); Sabbadin and Minello (1978); Sabbadin and Hamzaoglu (1981); S abbadin et al.
(1984, 1985); Sahu and Desai (1986); Shibata and Tamura (1985); Zuckerman and Aller (1986).
d a t a s h o w s t h a t it is b e t t e r to u s e as P N m a s s c r i t e r ion (as it w a s r e p e a t e d l y d o n e ) t he
va lues o f n i t r o g e n a n d oxygen r a t i o log ( N / O ) a n d h e l i u m - h y d r o g e n r a t i o log ( H e / H ) .
T o r r e s - P e i m b e r t (1985) t a k e s ( type I P N e b y a u t h o r c l a s s i f i ca t ion ) t he r a t i o s
H e / H > 0 .125 a n d N / O > 0.3 as the m a s s c r i te r ion . H o w e v e r , as is seen f r o m F i g u r e 2
32 P. R. AMNUEL ET AL.
these values change within the strip between lines I. Evidently, the PN subdivision by chemical composition given by Torres-Peimbert (1985) does not show the observed picture. Theoretical tracks of chemical evolution derived by Renzini and Voli (1978), Becker and Iben (1980) at quantitative agreement with observations (lines 1 and 2) do not give a qualitatively true picture too and cannot be considered as mass criteria.
We divided the observed strip of PN chemical composition change using criteria 1 and 2. Figures 2(b) and 2(c) show the PNe division boundary by its mass class. We held that 2 of the M-type PNe (criteria 1 and 2) must be situated higher than upper line M, and ~ of the L-type PNe must be situated lower than line L.
Thus, to the M-type PNe by criterion 3 (mass index + 1) we referred all PNe situated at the diagram 2 in the region A. To the I-type PNe (mass index 0) those situated in the region B, and to the L-type PNe (mass index - 1) those situated in the region C.
0 .5 I I u // ,
/ ~ 1 0 �9
0 ~. �9 �9 -
y . �9 ~ /
- 0 . 5 ~
ee ~*, �9
~ �9 om .
�9 * ~
- 1 . 0
- 1 . 5 i I t i a
- 1.2 - 1.0 - 0.8 log ~ - 0.6
Fig. 2a. The values of log(N/O) as the function of log(He/H) for the PNe with known chemical com- position, the corresponding data are given in Table II, The strip within which the dots are situated, is divided into three parts according to the PN mass types (see the text). The theoretical lines of the change in chemical composition of the stars are given: 1 - after second mixing, 2 - after the third one. 'A' is the region of massive
PNE, 'B' is that of intermediate ones, 'C' is that of low-mass ones.
PLANETARY NEBULAE IN THE GALAXY 33
0.5
~ Io t~
- 0 . 5
- 1 . 0
3
- 1 . 5
- 1 . 2
I I I / , I
/ /"
/
O ~
I) /
O
O
- 1.0 - 0.8 - o.6 He log ~-
Fig. 2b. The same as in Figure 2(a), only PNe, for which the CS masses are known, are given. The filled circles show the massive CS, Mcs > 0 .64Me; half-filled ones show the CS of intermediate masses, 0.64 M o > Mcs > 0.57 M e ; unfilled ones show the low-mass CS, Mcs < 0.57 M o. Region 'A' is that of
massive PNe, region 'B' is that of intermediate mass ones, region 'C' is that of low-mass ones.
Clear division on the M- and L-type CS in Figure 2 is a good observational con- firmation of the monotonous dependence between the CS mass and that of parent star.
With an increase of the parent star mass (i.e., with the increase of the contents of a number of chemical elements) the mass of the remnant grows also. One can better be
seen in Figure 3 where the dependences of nitrogen and neon contents in a PN on the CS mass are given. The data are taken from Tables I and II and are averaged for 6 regions of CS masses. Similar dependences, though less clearly expressed, exist also for some other elements (e.g., He and Ar).
Thus, the use of the first three mass criteria permit to consider the correctness of the adopted assumptions on the mass type of PNe.
34 1,. R. AMNUEL ET AL.
Fig. 2c.
~1o
o
- 0 . 5
- 1 . 0
1 . 5
/ O
O
O
/ �9 @ 0 �9
0
O o O
Ooo /
t I / I I I
. 2 - 1 . 0 - 0 . 8 N o - 0 . 6 log ~--
The same, the objects are divided according to cr i ter ion 2. The filled circles show mass ive PNe
according to cr i ter ion 2, unfilled ones show low-mass PNe.
The fourth criterion is directly connected with PN physical parameters. Here we use molecular hydrogen line observations. Irrespective of whether these lines are formed in outer layers of the PN itself or outside the PN, the very existence of these lines can be considered as an evidence that there is a powerful shell around a CS (i.e., one can consider the presence of H 2 lines to be an indication of PN mass).
At present the search for H 2 lines was carried out for 45 PNe by Storey (1984), Isaacman (1984a), Rodrigues etal. (1985), Schneider et al. (1987), Zuckerman and Gatley (1988). In 17 PNe, H 2 lines were detected, in 28 PNe they were not. Since now qualitative estimation of shell mass by H 2 lines is difficult, let us consider how the presence (and absence) of H 2 lines correlates with the first three mass criteria of PNe. We think that the presence of H2 suggests the PN being massive (index + t); the absence testifies to low-mass ones (mass index - 1).
PLANETARY NEBULAE IN THE GALAXY 35
8.4 o,1
+
b,O 0
H
7.6
8 . 8
cx]
+
~i~8.4 o
r-I
I I I
Fig. 3.
I I I
8 . 0
I I I
- 0.2 log~- 0 --|
The dependence of the PN chemical composition on the CS mass.
In 11 cases out of 15 there is a coincidence of mass indices by criteria 1 and 4, in
one case the criteria contradict each other, in the rest three cases the CS are considered to be intermediate mass by criterion 1 (mass index 0).
The agreement of mass indices by criteria 2 and 4 is observed in 23 cases out of 36, in two cases the criteria contradict each other, in eleven cases the PNe have a mass index 0 by criterion 2.
A comparison of criteria 3 and 4 is shown in Figure 4. Not only good qualitative
agreement between criteria is seen but the fact that the mass class division boundaries by chemical composition agree well with criterion 4.
Thus the data on the presence or absence H 2 lines in PNe can be used for outlining the massive and low-mass PNe. The advantage of this criterion is that it is (as well as criteria 2 and 3) not dependent on PN distance. Its deficiency rests in the fact that, by their use, the class of intermediate mass PNe is not selected.
36 P . R . A M N U E L ET AL.
0.5
~ 1 o
N ) o
r - I
0
0.5
/
/ /
t
- 1 , 0
[ | I I | I
/ ' //
/ /
/ �9
/ - . / / , �9 /
/ / -Q �9 �9 /
o / o o ~ / o..
o o ~ /
/ - 1 . 5 I ) / ~ l 4 I
-- 1 . 2 - 1 . 0 - 0 . 8 l o ~ - 0 . 6
Fig, 4. The same as in Figure 2, PNe are divided into mass types according to criterion 4 (the presence of H2). Filled circles show PNe in which H 2 is detected, unfilled ones show those PNe in which H 2 is not
detected.
Thef i f th criterion is also not connected with the distance to PNe. Massive or low-mass PNe are determined by the value of the Zanstra temperature ratio of CS
T~ (H I)/Tz (He II). Figure 5 shows the dependence of Tz (H Q/T z (HelI) ratios on the value of surface
radio brightness Z at the frequency of 5 G H z (in quality it gives the dependence on PN diameter D as well since with the increase of D the value 2 decreases). Here the PNe being obviously massive or of low-mass by criteria 1-4 are plotted. As one can see at
< 10 - 18 W m - 2 Hz - 1 there is a real difference between the M- and L-type PNe: the value of T~(H I)/Tz(HeII ) ratio of the L-type PNe is less than 0.7, that of the M-type
P L A N E T A R Y N E B U L A E I N T H E G A L A X Y 37
0,2
0
- 0 . 2
- 0 . 4
O A @ @
�9 O �9
O
0 O0 o
0 O0 0
o o :o oo o O O - O - O ~
I i L i I
- 17 - 18 - 19 - 20 - 21 log Z
Fig. 5. PNe are divided into mass types according to criterion 5: the ratio of the Zanstra temperatures T~(H I)/T~ (He II). The dependence on E is given. Filled circles show PNe, considered massive according to criteria 1-4; half-filled ones show intermediate mass PNe according to criteria 1-4; unfilled ones show
low-mass PNe. Regions A, B, and C correspond to M-, I-, and L-type PNe.
PNe is more than 0.8. In the region of Z > 10 - is W m -2 Hz - 1 it is more difficult to
distinguish the M-type PNe from the L-type ones at T ~ ( H 0 / ~ ( H e n ) ~ 0.7-0.9.
Tylenda (1983) showed that physically this effect is explained by more rapid evolution
of the CS with greater temperature and mass. According to the calculations, this leads
to a slower hydrogen recombination in comparison with helium (see also work by Sabbadin, 1986a, where the division of PNe at the diagram of Tz (HO/T~(Hen ) dependence on D is connected with the morphological types B and C).
The fifth criterion relates to mixed ones: it is dependent on both the mass of the CS and the parameters of PN itself.
Table I I I gives mass indices by the fifth criterion for 91 PNe. The index + 1 denotes
the PNe with T z (H I ) /T z (He IX) ~ 0.8 (region A in Figure 5). The index - 1 denotes PNe from the region C in Figure 5 and index 0 those from the region B.
The values of frequency at which the tow-frequency break of PN radio emission in
continuous spectrum begins, can be considered the sixth criterion. Radio emission spectra by the data (e.g., Taylor et al., 1987) can be approximately constructed for 51 PNe. At 5 G H z PNe are always optically thin (in Table IV the values of Z are given). However, at lower frequencies the optical thickness increases approximately as
v~., _ a s Tel. 35 , (1 )
38 P. R. AMNUEL ET AL.
T A B L E I I I
PK name Mass index according to cr i ter ia
1 2 3 4 5 6 7 8 9
The Mass
average class
10 mass index
O+ 12~
O+ 3~
O - 3~
1 - 3~
1 - 4~
1 - 4~
1 - 6~
2 + 5~
2 - 2~
2 - 3~
2 - 3~
2 - 4~
2 - 4 ~
2 - 6~
2 - 6~
2 - 1 3 ~
3 + 5
3 + 5~
3 + 3~
3 + 2~
3 - 2~
3 - 4~
3 - 4~
3 - 4~
3 - 6~
3 - 14 ~ 1
3 - 17~
4+ 4~
4 + 2~
4 + l ~ 4 - 2 2 ~
5 + 6~
5 + 5~ 5 + 5~
5 + 4~
5 - 6~ 6 + 8~ 6 + 4~
6 + 4~ 6 + 3~
6 - 3~ 7 + 1~
7 - 4~ 8 + 3~ 8 - 1~ 8 - 4~
8 - 7~
- 1
- 1 - 1 - 1
+1 0 0 0
- 1 - 1
- 1
- 1
- 1
- 1
+1
- 1
- 1
- 1
+ 1 0 - 1
- 1 - 1 - 1
0 - 1 - 1 + 1 + 1
+1 - 1 - 1
+ 1 +1
+1 - 1 0
+ 1
- 1
+ 1 0 0 - 1
- 1
0 / + 1 +1
+ 1 + 1 +1
- 1 - 1
+ I
+ 1 +1
+1 +1
- 1 0 - 1
+ 0 . 5
- 1
- 1
- 1
- 1
- 1
- 1
- 1
- 1 - 1
- 1 - 1.00(3) L
- 1 . o o ( 1 ) L
- 1 /0 L / I
- 1 . O 0 ( 1 ) L
- 1 - 1.00(2) L
- 1 - 1 . 00 ( 2 ) L
- 1 - 1 . 0 0 ( 4 ) L
+ 0.25 (4) I
- 1.00(3) L
- 1 . 0 0 ( 1 ) L
- 1 .oo (1 ) L
- 1 / 0 L / I
0 (3) I - 1 - 1 . 0 0 ( 4 ) L
- 1 - 1 . 0 0 ( 1 ) L
- 1 - 0 . 1 7 ( 6 ) I
- 1 - 1 . 0 0 ( 1 ) L
- 1 - 1 . 0 0 ( 1 ) L
- 1 /0 L / I
- 0.50 (4) I
+ 1.00 (2) M ?
+0.30(5) I - 1 /0 L / I
- 1 - 1.00(2) L
- 1 - 1 . 0 0 ( 1 ) L
- 1 - 1.00(2) L
- 1 o ( 2 ) I
- 1 / 0 L / I ?
- 1 - 1 . 0 0 ( 1 ) L
- 1 - 1 . 0 0 ( 1 ) L
- 1 / 0 L / I
- 1 - 1 . 0 0 ( 1 ) L
- 1 /0 L / I
- 1 - 1.00(2) L
- 1 - 1 . 0 0 ( 2 ) L
- 1 0 ( 3 ) i
- 0.66 (3) L .9
- 1 . 0 0 ( 1 ) L
+ 0.88 (4) M
- 1 - 1 . 0 0 ( 2 ) L
+ 1.00(6) M ?
- 1 - 1.00(2) L - 1 - 0.86 (7) L
PLANETARY NEBULAE IN THE GALAXY 39
Table IH (continued)
P K n a m e Mass index accord ing to cr i ter ia
1 2 3 4 5 6 7 8 9
The M a s s
average class
10 mass index
9 + 1 4 ~ 0 - 1 - 1 +1 + 1 - 0 . 5
9 - 5 ~ 0 - 1 0 0 / + 1 - 0 . 5
1 0 + 1 8 ~ - 1 + 1 +1
10+ 0~ +1 + 1 0 + 1 0 + 1
1 0 - 1~ - 1 0 +1
1 0 - 6~ 0 - 1 - 1
11 + 6~
1 i + 5~ 0 +1 +1 0
1 1 - 0~ - 1 --1 - 1 - 0 . 5
1 2 - 2 ~ 1
1 4 - 4 ~ 1
1 5 - 4~
1 6 - 1~ 1 6 - 4 O l
1 7 - 4~ 0 - 1
1 7 - 2 1 ~ 0 0 - 1
1 8 + 2 0 ~ - 1 1 9 - 2 3 O l
2 2 - 2~
2 2 - 3~
2 3 - 2~ - 1 +1
2 5 + 4 0 ~ - 1 - 1 - 1 - 1 - 1 - 1 - 1
2 5 - 4 ~ 0
2 5 - 11~
2 5 - 1 7 ~ - 1 0 0 - 1 +0.5
2 7 + 4~
2 7 + 0~
2 7 - 9~ - 1 - 1 - 1 - 1
2 8 + 5~
2 8 - 3~
2 8 - 4~
2 9 - 5~ - 1 - 1 0 - 1 - i - 0 . 5
31+ 5~
3 2 + 5~
3 3 - 2~ + 1 + 1 + 1 + 1 + 1 +0 .5
3 3 - 6~ 0 0 0 + 1 +1 3 4 + 1 1 ~ - 1 0 0 - 1 +1 - 1 - 1 - 1
3 4 - 6~ + 1 +1 +1 + 1 +1
3 5 - 0~ - 1 - 1
3 6 + 1 7 ~ - 1 - 1 - 1 - 1 +1 - 1
3 6 - 1~ + 1 0
3 6 - 5 7 ~ + 1 +1 + 1 + 1 +1 +1 +1 3 7 - 6~ 0 - 1 - 1 + 1 0 - 1
3 7 - 3 4 ~ - 1 0 0 - 1/0 0 0 3 8 + 1 2 ~ - 1 - 1 + 1 + 1
3 8 - 2 5 ~ 0 - 1 0
3 9 + 2~ 3 9 - 2~ 0
- 1 - 0 . 2 1 ( 7 ) I
0.20(5) I
- 1 0 ( 4 ) I
+ 0.67 (6) M
0 (3) I
- 1 - 1 - 0 . 8 0 ( 5 ) L
- I - 1.00(1) L
- 1 1/0 + 0.17(6) I
- 1 - 0 . 9 0 ( 5 ) L - I - 1 / 0 - 0 . 7 5 ( 2 ) L
- 1 /0 L / I
- 1 /0 L / I ?
?
- 1/0 - 0.50(3) I
- 1 - 0.50(4) I
- 1 - 1 . 0 0 ( 2 ) L
- 1 - 1 . 0 0 ( 1 ) L
- 1 /0 L / I
- 1 / 0 L / I
- I - 0.33(3) I
- 1 - 1.00(8) L
0 (1) I
- 1 - 1 . 0 0 ( 1 ) L
- 1 - 0.42 (6) I
- 1 /0 L / I ?
- 1 - 1 - 1 . 0 0 ( 6 ) L
- 1 - 1 . 0 0 ( 1 ) L ?
?
- 0.75(6) L
- 1 / 0 L / I
- 1 /0 L / I
+ 0.92(6) M
- 1 / 0 +0 .25(6 ) I
- 0 . 5 0 ( 8 ) I - 1/0 - 1 +0 .50(7 ) I
- 1.00(2) L
- 1 - 0 . 7 1 ( 7 ) L
+0.50(2) I + 1.00(7) M
- 1/0 - 0.36(7) I - 1/0 - 0 . 2 9 ( 7 ) I - 1 - 0.20 (5) I
- 1 - 0.50 (4) I ?
0 (1) I
40 P. R. AMNUEL ET AL.
Table II1 (continued)
P K n a m e Mass index according to cr i ter ia
1 2 3 4 5 6 7 8 9
The Mass
average class
10 mass index
4 1 - 2 ~ 0 + 1
4 2 - 6~ - 1 - 1
42 - 14 ~ 1
4 3 + 3 7 ~ 0 - 1 - 1
4 5 - 4~ - 1
4 6 - 4~ - 1 + 1
4 8 + 2~
50+ 3~ 0 - 1 +1 0
51+ 9~ 0 - 1 0 - 1 - 1 +1
5 1 - 3~ 5 2 - 2~ + 1 + 1
5 3 - 1~ 5 4 - 1 2 ~ - 1 - 1 - 1 - 1 - 1
55+ 2~ 5 7 - 8~ - 1 - 1 - 1 +1 - 1
5 8 - 1 0 ~ 0 0 + 1 - 1 - 1 - 1 - 1
6 0 - 3~ + 1 +1 0 + 1 + 1 0 1
0 + 1 + 1 + 0 . 5
- 1 - 1
0 + 1 + 1 - 1
- 1 - 1 +0.5
- 1 +1 0 - 0 . 5
6 0 - 7~ - 1 - 1
6 0 - 7~ +1 0 +1
61+ 2~
6 1 - 9~ 0 - 1 - 1
6 3 + 1 3 ~ 0 + 1 0 + 1 +1
6 4 + 4 8 ~ - 1 0 - 1 - 1
6 4 + 5~ - 1 - 1 + 1 - 1
65+ 0~ - 1 - 1
6 5 - 2 7 ~ - 1 - 1 - 1
6 6 - 2 8 ~ - 1 - 1 - 1
6 8 + 1
6 9 - 2~
7 1 - 2~
7 4 + 2~
8 2 + 1 1 ~ 82+ 7~
8 3 + 1 2 ~
8 4 - 3~
8 6 - 8~
8 8 - 1~
89+ 0~ 8 9 - 5~
9 3 + 5~ - 1 9 3 + 1~
9 5 + 0~ 9 5 - 2~ 9 6 + 2 9 ~ 0 - 1 - 1
9 6 + 1~
1 0 0 - 5~ - 1 - 1 1 0 0 - 8~ 0 + 1 104+ 7~ 0
+ 0.58 (6) - 1 - 1.00(5) - 1 - 1 . 0 0 ( 1 )
- 1 -0 .25 (8 ) - 0.62 (4)
- 1/0 -0 ,14 (7 )
0 ( 4 )
- 1/0 - 0 , 3 6 ( 7 )
+ 1 . o o ( 2 )
- 1/0 - 0 . 9 2 ( 6 )
- 1 - 0.67 (6)
- 1 - 0.50 (8) + 0.75 (7)
- 1 / 0 - 1 - 0 . 8 8 ( 4 )
0 - 1 - 0.5 - 1 - 0.07 (7)
- 1/o + 1 - 0.5 - 1/0 - 0.33 (6)
0 0 + 0.5 + 0.44 (8)
+ 1 +0.5 - 1 - 0 . 3 6 ( 7 )
0 - 1 - 0 . 5 - 0 . 5 0 ( 7 ) - 1 - 1.00(3)
- 1 - 1 - 1 - 1 - 1.00(7)
0 - 1/0 - 1 - 0.75(6)
0 +1
- 1 - 1 - 1
- 1 +1 - 1 - 1
0 - 1 - 1 - 1 - 1 - 0 . 5
- 1 - 1 - 1 - 1
+1 + 1 +1 + 1 + 1 + 1 +0.5
0 +1 - 1 - 1 + 1
+1 0 - 0 . 5
0 +1 - 1 +1 +1 + 1
0 - 1 - 1 - 1 - 1 - 1 0 + 1 - 1 +1 - 0 . 5 - 1 / 0
0 + 1 + 1 - 1/0
+1 - 1 0 +0 .20 (5 )
- 1 - 1 - 1 - 1 . 0 0 ( 6 )
0 / + 1 0 - 0 . 5 0 (5)
- 1 - 1 - 1 - 1 - 1 . 0 0 ( 6 )
- 0.75 (6)
- 1.00(4) + 0.93 (7)
- 1 - 0 . 1 7 ( 6 )
+0 .17(3)
+ 0.50(6) - 0 . 8 3 ( 6 )
- 0 . 1 4 ( 7 )
+ 0.38 (4)
- 1 - 1.00(1)
0 - 1 - 0.60 (5)
- 1 - 1 - 1 - 1 - 1 - 1
0 - 0 . 5
- 1.00(6) - 1 - 1 - 0.50 (6)
- 1/0 - 0.25(4)
I
L
L
I
L
I ?
I
I ?
M ?
L ?
L
I
M L
I
L/I
I
I
I
I
L
L
L ?
I
L I
L
L
L
M I
I
I
L I
I ?
L
L ?
L I
I
PLANETARY NEBULAE IN THE GALAXY 41
Table III (continued)
P K n a m e M a s s index accord ing to cr i ter ia
1 2 3 4 5 6 7 8 9
The Mass
average class
10 mass index
106 - 17 ~ I
107+ 2~ 1 0 7 - 2 o 1
1 1 1 - 2~
1 1 8 - 8~
1 1 8 - 7 4 ~
1 1 9 - 6~
120+ 9~
123 + 34 ~ 1
130+ l ~ 130 - 10 o 1
1 3 0 - 11~
138 + 2 ~ 1
144+ 6~
1 4 7 - 2~
148 + 57 ~ 1
159 - 15 ~ 1
161 - 14 ~ 1
165 - 15 ~ 1
166+ 10~ 1 6 9 - 0 o 1
1 7 1 - 2 5 ~
1 7 4 - 14~
1 7 8 - 2
1 8 4 - 2~
189+ 19~
189+ 7~
190 - 17 ~ 1
1 9 3 - 9~
194+ 2~ 196 - 10 o 1
196 - 12 ~ 1
197+ 17~
1 9 7 - 2 ~ 1
1 9 8 - 6~
2 0 4 + 4~ 205 + 14 ~ 1
206 - 40 ~ 1
2 1 0 + 1~
2 1 1 - 3~
2 1 2 + 4~ 2 1 4 + 7~
2 1 5 + 3~ 2 1 5 - 2 4 ~
215 - 30 ~ 1 217 + 14 ~ 1
220 - 53 ~ 1 2 2 1 - 4~
- 1 0 - 1 - 1 - 1 - 1 - 1 / 0
0 - 1 - 1 +1 +1 +0.5
0 +1 + 1 - 1 - 1 +1 0 - 1
- 1 0 - 1 - 1
0 - 1 - 1 - 1 0 0 - 1
- 1 - 1 +1 - 1
+1 - 1 - 1 - 1 +0.5
- 1 - 1 - 1 0 / + 1 - 1 - 1
0 0 - 1 + 1 +1 +0 .5 - 1 / 0 +1 +1 +1 +1 + I +1
0 - 1 0 - 1 + 1 - 1
0 - 1 -O.5
0 + 1 + 1 + 1 0 - 1 - 1 + 1 - 1 0 - 1
- 1 - 1 - 1 + 1 0 - 0 . 5 - 1
0 - 1 - 1 0 - 0 . 5 - 1
- 1 - 1 - 1 - 1 - 1 / 0 - 1 / 0
- 1 - 1 - 1 0 - 1 - 1 - 1 - 1 / 0
- I - 1 - 1 - 1 - 1
0 +1 - 1
- 1 - 1 - 1/0
- 1 - I - 1 - 1 - 1
0 0 0 - 1 0 + 1
0 0 0 0 +1 - 1
- 1 - 1 - 1 - 1 + 1 - 1 - 1
- 1 0 - 1 +1 - 1 + 1 +1 0
- 1 0 - 1 - 1 0 - 1 - 1/0
- 1 - I - 1 - 1 - 1 - 1 0 - 1 - 1 / 0
+ 1 +1 - 1
+1 +1 + 1 +1 + 1 - 1 - 1 - 1 - 1 - 1 - 1 + 1 - 1 - 1
+1
- 1 - 1
- I - 1 - 1/0 - 1 - 1 - 1 - 1/0
+1 +1 0 + 1 - 1 - 1 - 1 - I - 1 - 1 - 1 0 / + 1
0
+1 + 1 +1 +1 - 1 - 1 - 1 - 1 0 - I - 1
- 0 . 7 9 ( 7 ) L
+ 0.08 (6) I
+ 0.66 (3) M
- 0 .40 (5 ) i
- 0.75 (4) L
- 0 . 5 7 ( 7 ) I
- 0.50(4) I
- 0.30 (5) I
- 0 . 7 5 ( 6 ) L
+0 .14(7 ) I
+ 1.00(6) M
- 0.50 (2) I
- 0.25 (4) I
-0.50(3) I + 0.66 (3) M
- 0 . 2 5 ( 8 ) I
- 0.50 (7) I
- 0 . 5 8 ( 6 ) I
- 0.83 (6) L
- 0 . 8 1 ( 8 ) L ?
- 1.00(5) L
0 (3) I
- 0.83 (3) L
- 1.00(5) L
0 (6) I
0 (6) I
- 0 . 7 1 ( 7 ) L
- 1 . 0 0 ( 1 ) L
+0 .14(7 ) I
- 0.64 (7) L
- 1 . 0 0 ( 1 ) L
- 0 . 8 1 ( 8 ) L ?
?
+0 .33(3 ) I + 1.00(5) M
- 0.78 (9) L
+ 1.00(1) M
- 1.00(2) L
- 0 . 8 3 ( 3 ) L - 0 . 8 8 ( 4 ) L
+ 0.75 (4) M - 0 . 8 1 ( 8 ) L
0 (1) I + 1.00 (4) M
- 0 . 8 6 ( 7 ) L ?
42 P.R. AMNUEL ET AL.
Table III (continued)
PK name Mass index according to criteria
1 2 3 4 5 6 7 8 9
The Mass
average class
10 mass index
221 - 12 ~ 1
2 2 3 - 2~
226+ 5~
227 + 33 ~ 1
228+ 5~
231 + 4~
2 3 2 - 1~
233 - 16 ~ 1 234+ 2~
236+ 3~
238 + 34 ~ 1
239 + 13 ~ 1
241 + 2~
2 4 2 - 1 1 ~
2 4 3 - 1~
245+ 1~
252+ 4~
254+ 5~
2 5 8 - 0~
261 + 32 ~ 1 261+ 8~
261+ 2~
2 6 3 - 5~
2 6 4 - 8~
264 - 12 ~ 1
265+ 4~
2 6 9 - 3~
272+ I2~
264+ 2~
2 7 5 - 2~
2 7 5 - 2~ 2 7 5 - 4 ~ 1
2 7 5 - 4~
2 7 7 - 3 ~
278+ 5~ 2 7 8 - 5 ~
2 7 8 - 6 ~
2 7 9 - 3 ~ 2 8 1 - 5~ 283 + 2 ~ 2 8 5 - 2 o 1
2 8 5 - 5 ~ 1
285 - 14 ~ 1 2 8 6 - 4~
2 8 8 - 2 ~ 1
2 8 8 - 5~ 289+ 7~ 2 8 9 - 0~
+1 0
0
+1 0 0 / + 1
+1 - 1 0 0
- 1 - 1 - 1
+1 + l +1 +1 +1 +1 +1 +1
0 0 +1 - 1
0 - 1 0 0
+1
0 +1 0 +1 0 / + 1
+1
- '1 - 1 - 1 - 1 - 1 - 1 - 1 - 1
+1 +1 +1 +1
- 1 0
0 +1 +1 +1
+1 0 - 1 - 1
- 1 - 1
0
+1
- 1
- 1
- 1 - 1
0 - 1 - 1
+1 - 1
- 1 - 1
0 0 /+ 1
- 1
+1
0 0 /+ 1
- 1 +1
- 1
- 1 - 1 0
- 1 - 1
- 1 + 0.25 (6)
- 1
- 1
- 1 - 1
- 1
- 1
- 1/0 - 1
- 1
- 0 . 5 0 ( 2 )
- 1.00(1) - 1.00(2)
0 (4)
- 1.00(4)
+ l.O0(8)
- 0.20 (5)
- 0.42 (6)
0 (2) + 0.50 (5)
o + 0,50 (2)
0/+ 1 - 0.94(9)
- 1 + 0.60(5)
- 1/0 - 1/0 +0.25(2)
- 1 -1 .oo(2 ) - 0.75 (4)
- 1/0 +0.43(7)
- 0.50 (2) - 1 -1 .oo(1 )
+ 1.00(1)
- 1/0 +0.25(2)
- 0.25 (6)
- 1 / 0 +0.25(2) o (2)
- 1 ,00 (4 )
- 1 . 0 0 ( 1 )
- 1 . 0 0 ( 1 )
- 1 - 0 . 8 0 ( 5 )
- 0 . 8 0 ( 5 )
- 1 -1 .oo(1 )
I ?
I
L
L I ?
L
M ?
I
I ?
I
I ?
?
I ?
L
M ?
L/I
I
L
L ?
I ?
?
?
I
L
M
I
I
I
I
L ?
L
L L
L ?
2 L ?
P L A N E T A R Y N E B U L A E IN T H E G A L A X Y 43
Table IH (continued)
PK n a m e M a s s index a c c o r d i n g to c r i te r ia
1 2 3 4 5 6 7 8 - 9
The M a s s
ave rage c lass
10 m a s s index
2 9 0 + 7~
2 9 1 - 4 ~
2 9 2 + 4 ~
2 9 2 + 1~
2 9 2 + 1~
2 9 4 + 4 3 ~ 0 0 - 1
2 9 4 + 4 ~ 0 - 1
2 9 6 - 3~ 296 - 20 o 1
2 9 8 - 0 ~
2 9 8 - 4 ~ 1 3 0 0 - 2 o 1
303 + 40 ~ 1
3 0 4 - 4~
3 0 6 - 0 ~ 1 3 0 7 - 3 o 1 - 1 0
3 0 7 - 4 ~ 1
308 - 12 ~ 1
3 0 9 - 4 ~
3 0 9 - 4 ~ + 1 0 + 1
3 1 0 - 2 ~
3 1 1 + 2~
3 1 2 + 10~ - 1
3 1 2 - 1~
3 1 6 - 13~ - 1 - 1 - 1
3 1 6 + 8~ - 1 - I
3 1 7 - 5~
3 1 8 + 4 1 ~ - 1 - 1
3 1 8 - 2~
3 1 9 + 1 5 ~ + 1 0
3 2 0 - 9 ~ 1 - 1
3 2 1 + 2~
321 + 2 ~
3 2 1 + 1~
32 l - 16~
3 2 2 - 0~
322 - 2 ~ 1
322 - 5 ~ 1
3 2 3 + 2~
3 2 3 - 2 ~ 1
3 2 4 + 2~
3 2 4 - 1~
3 2 5 + 3~
3 2 5 - 4 ~ 1
3 2 7 + 10 ~ - 1 - 1 - 1
3 2 7 - 1~
3 2 7 - 1~
3 2 7 - 2 ~ 1
- 1 - 1
- 1 + 1
- 1
+ 1
- 1
- 1
+ 1
- 1
0 + 1
- 1
+ 1
- 1
0
- 1
- I
+ 1
+ 1
- 1
+ 1
+ i - 1
0 0 / + 1
+ 1
+ 1
+ l
+ 1 - 1
0 0
+ 1
0 + 1
- 1
- 1
- 1
+ 1 - 1/0
- 1 - 1
- 1 /o
- 1 / o
-1
- 1 / o
9
- 1.00(1) L
- 1/0 L/I
+ 1.00(1) M
9.
- 1 - 0.50 (8) I
- o . o 8 ( 6 ) i ?
- 1 - 0.33 (3) I
- 1 . 0 0 ( 1 ) L
+ 1.00 (1) M
9.
- 1/0 + 0 .25(2) I
0 (2) I
9.
0 (6) I
+ 0.25 (2) I
- 1 - 1 . 0 0 ( 1 ) L
9.
+ 0.50 (6) I ?
9.
- 1 / 0 - 0 . 8 3 ( 3 ) L ?
- 1/0 - 0 .92(6) L
- 1 - 1.00(3) L ?
- 1/0 - 0 . 9 0 ( 5 ) L
9.
- 1 + 0 . 4 4 ( 8 ) r
- 1 - 1.00(2) L
- 0.75 (2) L
9.
9.
- 1 - 1 . 0 0 ( 1 ) L ?
?
0 (1) I
- 1 . 0 0 ( 1 ) L
- 1 . 0 0 ( 1 ) L
9.
- 1 .00 ( 1 ) L
9. 9.
- 0 . 7 1 ( 7 ) L
+ 1.O0(1) M
9.
L/I
44
Table 1II (continued)
P. R. A M N U E L ET AL.
P K name Mass index according to cr i ter ia
1 2 3 4 5 6 7 8 9
The M a s s
average class
10 mass index
3 2 8 - 2~
329+ 2~
3 3 0 - 3~
331 + 16 ~ 1
3 3 1 - 1~
3 3 1 - 2 ~ 3 3 2 - 3~'1
333+ 1" I
3 3 4 - 9~
3 3 5 - 1 ~
336+ 1~
3 3 6 - 5~
3 3 6 - 6 ~ 1
338+ 5~
3 3 8 - 8~
341 + 13 ~ 1
341+ 5~
342+ 17~
342+ 0~
342 - 14" 1
345+ 0~
3 4 5 - 8 ~
3 4 6 - 8 ~
348 - 13 ~ 1
349+ 4~
349+ 1~
3 4 9 - 1~
350 + 4 ~ 1
351+ 5~
353 + 6~
354+ 4~ 3 5 5 - 2~
3 5 5 - 2~
3 5 5 - 4 " 2 3 5 5 - 6~
3 5 6 - 4 ~ 1 3 5 6 - 4 ~
3 5 6 - 5~ 357+ 7~ 357+ 3~
357 + 3~ 357+ 2 ~
357+ 1~
3 5 7 - 4 ~ 1 358+ 5~
358 + 4 ~ 1 358+ 3~ 358+ 3~
- 1
- 1
- 1
- 1 - 1
+1 - 1
+1 + 1 + 1 + 1
+1
- 1
- 1
0 + 1 - 1 0 + 1
- 1 - 1
+1 + 1 + 1 + 1
- 1 - 1
+ 1 + 1 +1
- 1
- 1
0
+1
+ 1
0 / + 1
- 1
+ 1 - 1
-1
-1
0 +1
0
-1
-1
-1
- 1/0 - 0.75(2) - 1.00(1)
- 1/o - 1 - 1 - 0.50 (4)
+ 1.00(4)
- l - 1.00(1)
- 1/0 + 0.25(2)
- 1/0 - 0.75 (2)
- 1/0 - 0 . 6 0 ( 5 )
- 1 - 1.00(1)
- 1 - 1 . o o ( 1 )
- 1/0 - 0.50(3)
- 1 - 1/0 - 0.75 (2)
+0 .14(7 )
- 1 - 1.00(3)
+ 1.00(4)
- 1 - 1.00(1)
- 1 . 0 0 ( 2 )
- 1 / 0 - 1 / 0 - 0 . 7 5 ( 4 )
- 1/o - 1 - 1 - 1.00(3) - 1 - 1/0 - 0.75(2)
+ 0.83 (6)
0 (1)
- 1 . 0 0 ( 1 )
- 1 / 0 - 1 - 0 . 7 5 ( 2 )
- 1 / 0 - 1 - 0 . 8 3 ( 3 )
- 1/0 - 1 - 0 . 6 2 ( 4 )
- 1/0
- 1 - 1 . 0 0 ( 1 )
- 1 / o - 1 / o
- 1 - 1.00(1)
- 1 - 1.00(2)
- 1/o - 1 - 1 - 1 . 0 0 ( 2 )
- 1 - 0 . 5 0 ( 2 )
- 1 - 1 . 0 0 ( 1 )
- 1 0 ( 2 )
- 1 . o o ( 1 )
- 1/0
- 1 - 1/0 - 0 . 7 5 ( 2 ) - 1 / 0
- 11o
L
L
L/I
I
M
L
I
L
L ?
?
L
L ?
I
L
I
L
M L
L
L
L/I L L
M
I
L
L
L
L
L/I
L
L/I L
L
L/I L
I
L ?
I
L L/I ?
L L/I
L/I
PLANETARY NEBULAE IN THE GALAXY 45
Table III (continued)
PK name Mass index according to criteria
1 2 3 4 5 6 7 8 9
The Mass average class
10 mass index
358+ 3~ -1 - 1.00(1) L 358+ 1~ -1 - 1.00(1) L 358- 0~ 0 0 -1 0 +0.25(4) I 358- 7~ +1 +1 +1 0 0/+1 +0.70(5) M 359+15~ -1 - 1.00(1) L 359 + 5~ ' - 1/0 L/I 359- 0~ +1 +1 +1.00(2) M 359- 1~ ? 359- 2~ -1 -1.00(1) L 359- 4~ -1 -1.00(1) L
where D is the diameter of PN; Te, the electron temperature; ne, the electron concen-
tration; f(e), the function o f the filling factor o f P N and the matter distribution in P N
(geometrical factor). Since the P N mass is determined as Mpn ~ neeD ~ then the fre-
quency at which the radio emission intensity decreases twice, can be written approxi- mately as
lCMpnf l (~) Vl/2 ~ T~/305/2 (2)
For P N with given diameter (dependence on T e is weak and one can neglect it) the
frequency Vl/z is determined by P N mass and geometric factor. In any case, since there
is a dependence of v~/2 on Mpn (or, generally, on P N parameters) one can try to use the
data on the value of Vl/2 as one of P N mass criteria. Since it is a question of comparing
equal-size PNe, let us construct a dependence of vl/2 on D for those PNe for which the
independent values o f distances d are known.
Figure 6 shows the M-, L-, and I-type PNe by criteria 1-5. Region A can be
considered to be the one where the M-type PNe are situated (index + 1), in region B
the I-type ones are situated (index 0), and in region C the L-type ones (index - 1) are situated.
This criterion can be directly used only for PNe with known d. Table I I I lists mass
indices by criterion 6, for those PNe for which distances were determined by
Z - D-dependences (see below). This circumstance lead to that beside earlier used
indices + 1, 0, and - 1, new designations, viz., - 1/0 and 0 / + 1, have appeared. This
means that, depending on the accepted P N distance, one can relate a P N to this or that
mass class. In these cases concluding the final mean value of P N mass index for the
case - 1/0 the value - 0.5 was accepted by criterion 6 and for 0 / + 1 the value + 0.5.
We shall do so further when the use of criteria depends on the use of the respective Z - D-dependence for determining the distances d.
The seventh criterion connects P N mass class with the value o f electron density n e in
a P N of given diameter. Figure 7 shows the values of n e for PNe with independent
46 P. R. AMNUEL ET A L
3.5
r~
3.0
�9
2.5
2.0
- 2.0
~ ,
o L \ . . . o
I I I
- 1.5 - 1.0 - 0.5 log D
Fig. 6. PNe are divided according to criterion 6. The dependence of the frequency vl/a of the break in radio emission spectrum on PN diameter D is given. Filled, half-filled, and unfilled circles show M-, I-, and L-type PNe according to criteria 1-5. Regions A, B, and C are correspondingly the regions of M-, I-, and L-type
PNe according to criterion 6.
distance determination. Just like at previous diagrams various mass type PNe are
shown, respectively. The subdivision of PNe into massive (region A) and low-mass (region C) ones is also observed here. Dividing lines, like those for previous criteria, are
made so that ~ of PNe, the M- and L-type by criteria 1-6, would be located correspond-
ingly in regions A and C. This criterion, like the previous one, is dependent only on physical parameters of PN
itself. However, the method of determining n~ by forbidden lines of some elements
usually gives the concentration values in some concrete PN region, but not the average
value by nebular volume (we carried out the averaging of n e by different observational data for each nebula). Therefore, a PN subdivision in the M- and L-type by criterion 7 in Figure 6 is somewhat worse than by previous one. For the same reasons we used in
Table I I I mass indices - 1/0 and 0 /+ 1. As it was stated in the Introduction, some authors earlier used morphological type
of a nebula as PN mass criterion. As the eighth criterion we also use this or that PN morphological features. It appeared that using the classification (Greig, 1971, 1972) one should relate about ~ of all the C-type PNe to the L-type ones by criteria 1-7 and about the same number of B nebulae to the M-type ones. Zuckerman and Aller (1986) give a more detailed classification of PN morphological types. The comparison with criteria
PLANETARY NEBULAE IN THE GALAXY 47
A
\
1 j I
- 2.0 - 1.5 - 1.0 - 0.5 log D
Fig. 7. PNe are divided according to criterion 7. The dependence of electron number density n e on PN diameter D is given. The designations are the same as in Figure 6 but according to criteria 1-6.
1-7 showed that Bp-nebulae can be related to the M-type (mass index + 1 in Table III),
A M and D R nebulae - to the L-type ones (index - 1), R, J, BR nebulae - to the I-type
ones (index 0). BPR nebulae are equally often met both among the M-type PNe and the
I-type ones. D nebulae belong to I- and the L-type. Therefore, in Table I I I there are
corresponding designations for them, 0 / + 1 and - 1/0. In those cases, when for a P N
a morphological classification was absent by Zuckerman and Aller (1986) but there was
a classification by Greig (1971, 1972), B nebulae had mass index + 1 and C-ones had
index - 1.
Kinematic criteria were also used for dividing PNe. The ninth criterion is the one using
the data on spatial velocity of a P N VI.SR (Schneider etal., 1983). This criterion
connects the PN-type with the mass of parent star. I f VLs R > 100 km s - 1 this obviously testifies to the fact that P N and its CS originate from a low-mass parent star, probably belonging to Population II o f the Galaxy. This criterion can only be used for deter-
mining the L-type PNe; if V~_sR < 100 km s - ~ it is impossible to establish the mass
48 P. R. AMNUEL ET AL.
of parent star. Therefore, in Table III criterion 9 is used only for PNe with VLS R ~ 60--100 km s - 1 (index - 1/0) and VLS R > 100 km s - 1 (index - 1).
The tenth criterion is used similarly: i.e., it deals with the PN distance to the galactic plane. The preliminary study of Z-distribution of PNe, the M-type by previous criteria, shows that their scaleheight fl over the galactic plane is ~ 100 pc. Therefore, one can practically be sure that a PN at the distance of Z > 300 pc from the galactic plane is the L-type. Such PNe are show in Table III by index - 1 . For the PNe within
Z = 200-300 Pc an index - 1/0 is used. Thus, in order to divide PNe into mass classes we use 10 criteria. Criteria 3, 8, 9, and
10 are stipulated by mass of a parent star, criteria 1 and partially 2 and 5 by the CS mass, criteria 4, 6, 7 and partially 2 and 5 by physical conditions in a PN. A good agreement between criteria confirms that, in principle, one can come to conclusions both on the CS mass and that of parent star by the PN characteristics.
In order to determine whether a PN is massive, criteria 1-8 are used, moreover, criteria 6-8 do not always give unequivocal results. Belonging to the I-type PNe is determined using seven criteria (1-3 and 5-8) and specifying the ambiguity of criteria 6-8. One can use all 10 criteria only to determine the L-type PNe.
In Table III the last-but-one column shows the averaged mass index of each PN which has radio observations. Here it is also shown what number of criteria was used to do averaging. The larger number of used criteria, the more reliable the value of the mean mass index K. Only those PNe for which K > [0.61 with number of the used criteria i _> 5 or K = 1 at i = 4 can certainly be related to the M- or L-type ones. In Table III all PNe with K > + 0.6 and K _< - 0.6 are formally related to the M- and
L-type, respectively. The accepted boundary of the values of K corresponds to that at least 4 out of 5
criteria confirm the accepted mass class. The matter is more complex with the I-type PNe. In Table III PNe with
-0 . 6 < K < + 0.6 are formally considered to be the I-type. However, this interval includes both really the I-type PNe and other ones too, either because of the lack of the used number of criteria or because of the errors in determining mass indices by this or that criterion. One can, for certain, relate to the I-type PNe those with K < ] 0.31 at i > 5 or at least with three zeros at i -- 4. Thus, in Table III 16 PNe can be related to the M-type, 29 PNe to the I-type, and 42 PNe to the L-type. Furthermore, we shall use these PNe for selecting calibrators for determining the 5" -D-dependence.
4. Low-Mass Nebulae (L-Type)
In order to construct the E - D-depence, it is necessary to select among PNe with reliably determined distances (see Section 2) those which can reliably be classified under the chosen mass class (in this case under the L-type PNe). Low-mass calibrators are: NGC 1514, NGC 2392, NGC 3211, NGC 3242, N G C 6567, N G C 6751, N G C 7662, A 36, K 648, and He 2-131. Let us consider the calibrators as they are given in
Table III.
PLANETARY NEBULAEIN THE GALAXY 49
N G C 6 5 6 7 ( P K 11 - 0~ Its distance was recently determined by Gatheir (1986a, b).
Two independent methods, 3 and 4, give approximately equal results, d = 1600 pc. The
angular diameter of this PN is taken 0--8 ' . '8 which corresponds to D = 0.07pc
( l o g D = - 1 . 1 7 ) . Art S s = 1 7 6 m J y (Phillips and Pottasch, 1984) we have logZ = - 17.909.
N G C 6751 (PK 2 9 - 5 ~ Its distance is determined by the method of individual
absorption. At d- - 1500 pc and 0 = 20"5 we have D -- 0.15 pc (logD = -0.83) . This PN was twice observed at 5 G H z (Phillips and Pottasch, 1984; Pottasch et al., 1984).
We accepted the mean value of intensity ( $ 5 ) = 59 mJy, then log E = - 19.119.
K 6 4 8 (PK 65 - 27 ~ 1). This PN is one of the most typical L-type nebulae. It is situated
in the globular cluster M15, its distance d ~ 10 kpc (Gathier etal. , 1983). Since it is distant, it is very difficult to determine the value of its radio emission intensity Ss and
angular diameter. According to Gathier et al. (1983), we accepted $5 = 4 mJy, 0 = 1" (/9 = 0.05 pc, logD = - 1.31, logZ = - 17.664).
N G C 7662 (PK 106 - 17~ PN distance was determined by three different methods
2 -4 (Sabbadin, 1986a). We accepted d = 600 pc, 0 = 20", ( S 5 ) = 640 mJy (Milne, 1979; Phillips and Pottasch, 1984; Pottasch etal. , 1984; Phillips, 1984), D = 0.06 pc,
logE = - 18.062.
N G C 1514 (PK 1 6 5 - 15~ Its distance was determined by spectral parallax and
average absorption. The value of d is accepted to be equal to 600 pc (see Sabbadin, 1986a), S 5 is determined reliably ( $ 5 ) = 255 mJy (Milne, 1979; Daub, 1982; Schneider
etal. , 1987), 0= 116", D = 0.34pc, logZ = - 19.988. N G C 2392 (PK 197 + 17 ~ 1). The distance is determined by three methods: namely,
2, 4, and 6. The determination of d according to PN expansion is, however, unreliable
since two measurements yielded contradictory results. Therefore, in this case the method is estimated by 1. The data on the measurements o f d are given in the work of Sabbadin
(1986a). We accepted d = 700 pc, ( S 5) = 252 mJy (Schneider et al., 1987; Pottasch
etal. , 1984; Phillips, 1986), 0 = 46"; hence, D = 0.15 pc and logE = - 19.188.
N G C 3242 (PK 261 +32~ It is a typical representation of the L-type PNe. Its
distance was determined by the methods 2 and 4. We accepted d = 500 pc. S 5 and 0 were reliably determined by Phillips (1984), Pottasch et al. (1984): ( S 5 ) = 878 mJy,
0 = 39':5 thus making this PN one of the most reliable calibrators. Its D = 0.095 pc, logZ = - 18.513.
N G C 3211 (PK 2 8 6 - 4~ Like Sabbadin (1986a) we accepted d = 2 kpc (deter-
mined by methods 3 and 4). The value o f S 5 = 80 mJy (Gathier et al., 1986) agrees with the measurements at other frequencies and can be considered reliable. 0 is accepted to be 0-- 15", thus D = 0.14 pc, logZ = - 18.709.
He 2-131 (PK 315 - 13 ~ 1). Gathier et al. (1986) determined the distance to it by the method of individual absorption. In this work E B _ v = 0.13 was used and d = 600 pc was obtained. However, according to 12 different EB _ v measurements the best value of EB_ v = 0.16, which leads to more reliable d = 800pc. At 0 = 6':5 we obtain D = 0.025 pc. This calibrator is the smallest one by size. At S 5 = 325 mJy (Gathier et al., 1986) we obtain logZ = - 17.380.
5 0 P , R , A M N ' ( ~ ' E L E T A L .
A 36 (PK 318 + 41 ~ The distance determined by mean absorption and the model
of CS is d = 5 0 0 p c . At S 5 = 2 1 5 m J y (Calabretta, 1982) and 0 = 4 5 0 " we get
D = 1.096 pc and logE = - 21.240. This PN is the largest one among the calibrators.
The values of Z of the L-type calibrators depending on D are shown in Figure 8.
Within the diameter interval 0.08-1 pc the dependence is approximated as
logE -- - (2 .81 + 0 .14) logD - (21.28 _+ 0.14) (3)
with the linear correlation coefficient 0.99.
At D < 0.08 pc this dependence becomes apparently flatter though the number of
calibrators here is not enough to come to a reliable conclusion. The comparison of the
Y,(D)-dependence with the similar one of Amnuel et al. (1984) within 0.08-0.4 pc shows
that both dependences are close to each other. Distances obtained by the previous
- 17~ i
I -I ~-. A
"- \
- 1 8 \ \ ~
\ \
\
- 1 9
- 2 0
- 2 1
1
t I U
\
�9 :~',',..
�9 ~ .,
\ ', \ \ \ ! \ ~ \
3,0r 7 ~ \\\
\ \ \
I _ _ I
- 1.5 - 1.0 - 0 . 5 l o g D o
Fig. 8. The •(D)-dependence of low-mass PNe. Empirical X(D)-dependence is shown by a solid line. Long dashed lines show the model dependences for the CS mass 0.57 Mo: 'A' corresponds to the mass loss rate at AGB stage ~r = 10 - 5 Me yr- 1, 'B' corresponds to M = 3 x 10 - 6 Mo yr- 1. Short dashed lines are those of equal ages (PN ages in years are shown at the figure). Calibrators designations: 1-PK315-13~ 2-PK65-27~ 3 -PK 11-0~ 4 - P K 106- 17~ 5 - PK261 +32~ 6 - PK 286-4~
7 -PK29-5~176176176
PLANETARY NEBULAE IN THE GALAXY 5 ]
Z(D)-dependence change inconsiderably if a PN is the L-type and has - 18.3 > log2 >~ - 20.2.
By use of the 2(D)-dependence alone, the dependence shown at Figure 8, distances for 220 PNe has been determined. A total of 131 of them are the L-type, 27 are the L/I-type, and the mass class of 62 PNe is unknown (they are designated by '?'). This constitutes about ~ of all PNe given in Table IV.
An important parameter characterizing a PN is its mass which is determined by
Mp,~ = O.0127neeD 3 1 + 4y (4) 1 + 1 . 5 y '
where y is the value of ratio He/H. For the L-type PNe ( H e / H ) = 0.10, the value of n e can be determined from the formula of free-free emission of the heated gas (the value of T e is accpeted as 1.2 x 10 4 K)
n~= 1.45x IO~2(~EY/2. \ e D /
(5)
Combining Equations (4) and (5), we have
Mpn = 2.32 x 101~ m , (6)
where Z is in W m - 2 Hz - 1, D is in pc. For the L-type PNe b = 1, for the I- and M-type it is 1.06 and 1.09, respectively.
In order to determine Mpn by the Z(D)-dependence it is necessary to know the value of e which is usually accepted to be constant and equal for all PNe (Pottasch, 1984; Gathier, 1987). Amnuel et al. (1984) showed that within 0.08 pc < D < 0.4 pc one accept ~ ~ D - 1. The value ofe can be estimated by (5) using the values o f n e determined by the method independent of Z(D), viz., by the ratio of forbidden lines intensities. Figure 9 shows the dependence of n e (by forbidden lines) on the diameter D (by Z(D)-dependence) for the L-type PNe. As is seen, the majority of points are situated near e = 1, no systematic change ofewith D is seen. The calculation for calibrators using independent values ofne, D gives e ~ 0.7-1 (for the majority o fPNe e ~ 1, and for some
of them ~ > 1, which apparently shows smaller values of the measured n3's ). Most likely, one can accept for the majority of the L-type PNe that e = 1.
Figure 10 shows the dependence of Mp, (D) for the L-type PNe. The value of ionized mass increases up to D ~ 1 pc reaching 0.6-0.7 M o. It is difficult to say whether the increase o f Mp~ continues at D > 1 pc. When the growth of Mpn stops it must lead to a steeper Z(D)-dependence at D > 1 pc and/or to the shift of dots at Figure 9 toward the line which corresponds to smaller values of e. Unfortunately, the L-type PNe with D > 1 pc are not practically observed. However, one must bear in mind that there is no L-type PNe with logZ < - 21.3 in Table IV, but there are the M- and I-type with such Z. Apparently, then the total mass of the L-type PNe can only a little be more than 0.6-0.734o.
TA
BL
E
IV
Na
me
M
ass
-
log
51
Ind
ep
en
de
nt
dis
tan
ce
Z -
D
de
term
ina
tio
ns
clas
s (W
m -
2 H
z -
l )
PK
O
ther
s d
(pc)
W
eigh
t lo
gD
d (p
c)
D (
pc)
logD
Z
(pc)
1 2
3 4
5 6
7 8
9 10
11
0 +
12
~ 1
1C 4
63
4
L
18.0
21
1700
0
.07
-
1.16
3
50
0 +
3
~ 1
He
2-2
50
L
18
.396
4
30
0
0.0
9
- 1.
02
22
0
0 -
3 ~
1 M
3-2
2
L/I
1
8.6
56
3
50
0
0.1
2
- 0.
93
160
1 -
3~
H
1
-47
L
17
.558
6
30
0
0.0
4
- 1.
36
33
0
1 -
4 ~
1 H
1
-55
L
1
7.8
34
8
60
0
0.0
6
- 1.
22
54
0
1 -
4~
H
1
-56
L
18
.059
6
70
0
0.0
7
- 1.
15
46
0
1 -
6~
S
wS
t 1
L
15
.92
9
10
00
1
- 2
.40
1
20
0
0.0
05
-
2.31
12
0
2 +
5
~ 1
NG
C
6369
* I
17.8
77
20
00
2
(2)
- 0
.56
7
80
0
.I1
-
0.97
7
0
2-
2~
M
2-2
3
L
15.8
57
23
00
0
.00
4
- 2.
35
80
2-
3~
M
1
-37
L
17
.442
5
30
0
0.0
4
- 1A
1 2
80
2-
3~
M
1
-38
L
17
.488
4
20
0
0.04
-
1.39
2
20
2-
4 ~
l H
1
-54
L
/I
t6.4
00
3
00
0
0.01
-
2.0
2
21
0
2-
4~
M
1
-42
I
18.6
48
41
00
0
.14
-
0.71
2
80
2-
601
M 2
-33
L
18
.141
5
20
0
0.0
8
- 1.
12
54
0
2-
6~
H
1
-63
L
18
.363
3
80
0
0.0
9
- 1.
04
36
0
2 -
13 ~
1
IC 4
77
6
I 18
.196
3
60
0
0.1
4
- 0
.86
8
10
3+
5
M2
-15
L
18
.358
4
10
0
0.1
0
-0.9
8
36
0
3 +
5
~ 1
H 2
-15
L
1
8.5
72
4
90
0
0.11
-
0.9
6
44
0
3 +
3
~ 1
H
2-1
7
L/I
18
.260
4
90
0
0.0
8
- 1.
07
25
0
3 +
2
~ 1
Hb
4
I 1
7.5
32
3
00
0
0.08
-
1.09
10
0
3 -
2~
IC
46
73
M
19
.050
5
30
0
0.3
9
- 0.
41
180
3-
4~
H
2-4
1
? 18
.028
19
00
0.0
7
- 1.
16
130
3 -
4~
N
GC
65
65
*
An
1
8.6
30
13
00
2(1
) -
1.21
13
00
0.0
6
- 1.
19
90
3-
4~
A
p 1
-12
L
/I
19.3
10
34
00
0
.20
-
0.7
0
24
0
3 -
6 ~
1 M
2-3
6
L
18
.98
2
27
00
0
.15
-0
.82
2
80
3 -
14 ~
1
Hb
7
L
17.9
39
33
00
0
.06
-
1.19
7
90
Tabl
e IV
(co
ntin
ued)
Nam
e M
ass
- lo
g Z
In
dep
end
ent
dis
tan
ce
Z -
D
det
erm
inat
ion
s cl
ass
(Win
-2
Hz-
l)
PK
O
ther
s d
(pc)
W
eig
ht
log
D
d (p
c)
D
(pc)
lo
gD
Z
(p
c)
1 2
3 4
5 6
7 8
9 10
11
3-
17~
H
b 8
L
16
.734
6
90
0
0.02
-
1.82
2
00
0
4 +
4 ~
1 M
1
-25
I
17.8
28
46
00
0.
10
- 0.
98
320
4+
2
~
H2
-25
L
/I
18.3
87
43
00
0.
09
- 1.
03
150
4+
1~
H
2-2
4
? 18
.737
4
10
0
0.12
-0
.90
80
4 -
22 ~
1
He
2-4
36
L
18
.904
3
00
0
0.14
-
0.84
11
00
5+
6
~
M3
-11
L
18
.583
3
20
0
0.11
-0
.96
33
0
5 +
5 ~
1 M
3
-12
L
/I
18.2
49
28
00
0.
08
- 1.
08
25
0
5 +
5~
H
2-1
6
L
19.7
20
36
00
0.
28
-0.5
5
32
0
5+
4
~
H
1-2
7
L/I
18
.474
3
10
0
0.10
-
1.00
2
20
5 -
6 ~
1 N
GC
6
62
0
L
18.5
02
42
00
0.
10
- 0.
99
44
0
6+
8
~
M
1-2
0
L
16.6
77
27
00
0.
01
- 1.
84
380
6+
4
~
H 2
-18
I
17.7
36
1280
0 0.
10
- 1.
01
770
6+
4
~
M
3-1
5
L
17.5
66
26
00
0.
04
- 1.
35
180
6 +
3~
M
1
-28
?
19.7
95
24
00
0.
30
- 0.
53
120
6-
3~
M
2
-31
L
17
.203
2
90
0
0.03
-
1.53
16
0
7+
1~
H
b6
M
17
.318
4
00
0
0.10
-0
.99
80
7-
4 ~
1 H
1
-65
L
17
.434
6
20
0
0.04
-
1.41
4
30
8 +
3 ~
1 N
GC
64
45
M
18.7
42
22
00
1
- 0.
45
1900
0.
31
- 0.
51
90
8-
1~
M
1-4
0
? 17
.266
13
00
0.03
-
1.50
20
8 -
4 ~
1 M
2-3
9
L
18.4
26
59
00
0.
10
- 1.
02
41
0
8-
7~
N
GC
6
64
4
L
16.9
62
20
00
0.
02
- 1.
67
24
0
9 +
14 ~
1
NG
C
6309
I
18.5
17
22
00
0.
18
- 0.
75
53
0
9 -
5 ~
1 N
GC
66
29*
I 18
.181
15
00
2(2
) -
0.95
18
00
0.14
-
0.87
16
0
10 +
18
~
M
2-9
I
19.7
89
3200
0.
47
- 0.
33
99
0
10 +
0 ~
1
NG
C
6537
* M
17
.488
2
40
0
2(I
) -
0.93
2
40
0
0.12
-
0.93
0
10
- 1~
N
GC
65
78
I 17
.954
2
00
0
2(2
) -1
.05
2
60
0
0.11
-0
.94
50
10 -
6 ~
1 IC
47
32
L
17
.827
3
10
0
0.06
-
1.23
3
20
Tabl
e 1V
(con
tinue
d)
-~
Na
me
M
ass
-
logZ
; In
de
pe
nd
en
t d
ista
nce
~
- D
de
term
ina
tio
ns
clas
s (W
m-
2 H
z-
1)
PK
O
ther
s d
(pc)
W
eig
ht
log
D
d (p
c)
D
(pc)
lo
gD
Z
(p
c)
1 2
3 4
5 6
7 8
9 10
11
11 +
6 ~
1
M 2
-15
L
18
.600
3
60
0
0.11
-
0.95
3
70
11 +
5
~ 1
NG
C
64
39
A
n
18.0
46
1200
1
- 1.
49
1200
0
.03
-
1.49
11
0
11 -
0
~
NG
C 6
56
7*
L
17
.909
16
00
4(2
) -
1.14
14
00
0.0
6
- 1.
20
0
12 -
2
~ 1
M
1-4
5
L
17.3
39
47
00
0.
03
- 1.
46
160
14
- 4
~ 1
M
1-5
0
L/I
18
.032
2
70
0
0.0
7
- 1.
16
180
15
- 4
~
M
1-5
3
L/I
18
.165
2
40
0
0.0
8
- 1.
11
170
16
- 1
~
M
1-4
6
? 18
.516
17
00
0.1
0
-0.9
8
30
16
- 4
~
M
1-5
4
? 19
.126
2
10
0
0.1
7
-0.7
7
140
17 -
4
~ 1
M
3-3
0
I 1
9.4
76
4
30
0
0.3
7
- 0.
43
31
0
17 -
21
~ 1
A
65
I 2
1.1
33
3
00
0
1.32
+
0.1
2
1080
18 +
20
~ 1
N
a 1
L
18
.302
3
60
0
0.0
9
- 1.
06
1200
19 -
2
3 ~
1
A 6
6
L
21
.37
4
82
0
1.08
+
0.0
3 3
20
22
- 2
~
M
1-5
7
L/I
18
.399
2
00
0
0.0
9
- 1.
02
70
22
- 3
~
M
1-5
8
L/I
18
.178
2
30
0
0.0
8
- 1.
10
120
23
- 2
~
M
1-5
9
I 17
.461
14
00
3 (2
) -
1.49
3
80
0
0.0
8
- 1.
12
120
25
+ 4
0 ~
1
IC 4
59
3
L
18.4
15
1600
0
.10
-
1.02
11
00
25
- 4
~
IC 1
295
I 2
0.5
93
17
00
0.8
7
- 0.
06
130
25 -
11
~ 1
A
60
L
2
1.0
20
2
10
0
0.81
-
0.09
4
00
25
-
17 ~
1
NG
C
68
18
I
18.3
92
22
00
1
- 0.
68
1600
0
.16
-
0.8
0
49
0
27
+
4~
M
2-4
3
L/I
17
.711
18
00
0.05
-
1.27
13
0
27
+
0~
M
2-4
5
? 17
.817
18
00
0.0
6
- 1.
23
0
27 -
9
~ 1
IC 4
84
6
L
17.2
65
28
00
0.
03
- 1.
50
44
0
28
+
5~
K
3-2
L
17
.591
3
60
0
0.0
4
- 1.
35
31
0
28 -
3
~ 1
Pe
1-2
1
? 18
.658
2
80
0
0.1
2
- 0.
93
140
28
- 4
~
Pe
1-2
0
? 18
.257
2
50
0
0.0
8
- 1.
07
170
29 -
5
~ 1
NG
C 6
75
1"
L
19.1
19
1500
2
(1)
- 0.
83
1700
0.
17
- 0.
77
150
31 +
5
~
K 3
-3
L/I
18
.469
2
20
0
0.1
0
- 1.
00
20
0
Tabl
e IV
(co
ntin
ued)
Na
me
M
ass
-
log
E
Ind
ep
en
de
nt
dis
tan
ce
Z -
D
de
term
ina
tio
ns
clas
s (W
m
2H
z
L)
PK
O
ther
s d
(pc)
W
eig
ht
log
D
d (p
c)
D
(pc)
to
gD
Z
(p
c)
1 2
3 4
5 6
7 8
9 10
11
32
+
5~
K
3-4
L
/I
19,0
87
29
00
0
.17
-0
.78
2
50
33 -
2
~ 1
NG
C
67
41
" M
1
7.8
32
17
00
3 (2
) -
0.9
3
22
00
0.
15
- 0.
81
70
33 -
6
~ 1
NG
C 6
77
2
I 2
0.1
90
14
00
1 -
0.2
4
1600
0
.65
-
0.1
9
170
34
+ 1
1~
N
GC
6
57
2
I 1
7,3
97
5
00
4
(3)
- 1.
50
1100
0
.07
-
1.15
2
00
34 -
6
~ 1
NG
C
67
78
I
18.9
23
31
00
0
.24
-
0.65
3
20
0
35
- 0
~
Ap
2-1
L
1
9.0
12
9
20
0
.16
-0
.81
0
36 +
17
~ 1
A 4
3
L
22
.07
0
49
00
1.
90
+ 0
.28
14
00
36 -
1
~ 1
Sh
2-7
1
I 2
0.6
14
14
00
0.8
7
- 0
.06
3
0
36
-
57 ~
1
NG
C
72
93
A
n
21
.09
0
100
1 -
0.3
9
140
0.5
9
- 0.
23
110
37
- 6
~ 1
NG
C
67
90
I
17
.53
0
11
00
1
- 1.
44
24
00
0.
08
- 1.
08
26
0
37
-
34 ~
1
NG
C
70
09
A
n
18
.21
4
60
0
1 -
1.12
3
90
0,
05
- 1.
31
22
0
38 +
12
~ 1
Cn
3-1
I
18,0
15
46
00
0
.12
-
0.9
2
95
0
38 -
2
5 ~
1
A 7
0
I 2
0.4
33
3
90
0
0.7
8
- 0.
11
15
00
39
+
2~
K
3-1
7
? 18
.068
8
70
0
.07
-
1.14
3
0
39 -
2
~ 1
M
2-4
7
I 1
8.0
88
3
50
0
0.13
-
0.8
9
130
41 -
2
~ 1
NG
C 6
781
I 19
.773
16
00
1 -
0.0
7
88
0
0.4
7
- 0
.33
3
0
42
-
6 ~
1 N
GC
6
80
7
L
17.2
03
41
00
0.
03
- 1.
53
42
0
42
-
14 ~
1
NG
C
68
52
L
19
,859
2
30
0
0.31
-
0.5
0
55
0
43 +
37
~ 1
NG
C 6
21
0
I 18
.273
18
00
0.1
5
- 0
.83
1
20
0
45
-
4 ~
1 N
GC
6
80
4
L
19
.35
8
1700
1
- 0.
45
1000
0.
21
- 0.
68
70
46
-
4 ~
1 N
GC
6
80
3*
I
17
.75
8
1800
2
(2)
- 1.
31
35
00
0
.10
-
1.01
2
50
48
+
2 ~
1 K
3-2
4
? 1
8.4
36
3
20
0
0.1
0
- 1.
01
110
50
+
3~
M
1
-67
I
19.8
95
1000
0.
51
-0.3
0
60
51 +
9
~ 1
Hu
2-1
I
17
.13
4
33
00
0.
05
- 1.
29
52
0
51 -
3
~ 1
M
1-7
3
? 1
8.0
20
2
90
0
0.0
7
- 1.
16
150
52
- 2
~
Me
1-1
M
18
.528
6
80
0
0.2
6
- 0
.58
2
40
53 -
1
~ 1
K 3
-38
?
18
.07
2
37
00
0
.07
-
1.14
7
0
Tabl
e IV
(co
ntin
ued)
~,
Na
me
M
ass
-
log
E
Ind
ep
en
de
nt
dis
tan
ce
N -
D
de
term
ina
tio
ns
clas
s (W
m
- ~
Hz
- 1
)
PK
O
ther
s d
(pc)
W
eig
ht
log
D
d (p
c)
D
(pc)
lo
gD
Z
(p
c)
1 2
3 4
5 6
7 8
9 I0
11
54
- 1
2~
N
GC
689
1 L
18
.433
6
50
1
- 1.
37
14
00
0
.10
-
1.01
2
90
55 +
2
~ 1
He
2-4
32
?
17.9
56
27
00
0
.07
-
1.18
9
0
57
- 8
~ 1
NG
C 6
87
9
L
18.2
31
34
00
0
.08
-
1.08
4
80
58 -
10
~ 1
IC 4
99
7
I 1
6.6
66
3
30
0
0.0
3
- 1.
58
58
0
60
-
3 ~
1 N
GC
68
53
*
An
2
0.2
56
2
50
3
(2)
- 0
.36
2
20
0
.39
-
0.41
10
60
- 7
~ 1
He
1-5
L
2
0.0
69
2
60
0
0.3
7
- 0.
43
31
0
60 -
7
~
NG
C
68
86
*
I 1
7.8
96
2
00
0
2(2
) -
1.20
3
40
0
0.11
-
0.9
6
42
0
.~
61 +
2
~
He
2~
44
2
L/I
18
.391
3
30
0
0.0
9
- 1.
03
110
.~
61 -
9
~ 1
NG
C
69
05
I
19.8
54
22
00
0
.49
-
0.3
0
35
0
63 +
13
~ 1
NG
C 6
72
0
An
1
9.6
60
5
50
4
(3)
- 0
.60
4
60
0.
21
- 0
.68
10
0
64
+ 4
8 ~
1
NG
C 6
05
8
I 19
.598
3
20
0
0.4
0
- 0
.39
2
40
0
t"
64
+
5 ~
1 B
D +
30
~
I 17
.372
7
00
3
(2)
- 1.
49
17
00
0
.07
-
1.16
14
0
65 +
0
~ 1
NG
C 6
84
2
L
19
.67
7
98
0
0.2
7
- 0
.57
0
65 -
2
7 ~
1
K 6
48
*
L
17
.66
4
10
00
0
2(1
) -
1.31
1
00
00
0
.05
-
1.29
4
70
0
~
66 -
28
~ 1
N
GC
7
09
4
L
21
.08
9
19
00
0
.86
-
0.0
7
90
0
68 +
1
He
2-4
53
?
19
.85
0
26
00
0.
31
- 0.
51
50
69
- 2
~
NG
C
68
94
" A
n
19
.67
6
12
00
3
(2)
-0.6
0
10
00
0
.22
-0
.67
4
0
71 -
2
~
M
3-3
5
L
16
.52
4
16
00
0.
01
- 1.
94
50
74
+
2 ~
1 N
GC
68
81
I 1
7.3
12
3
20
0
0.0
6
- 1.
19
110
82 +
11
~ 1
NG
C
68
33
L
1
6.6
14
3
80
0
0.01
-
1.89
7
10
82 +
7
~ 1
NG
C
68
84
L
17
.639
1
60
0
1 -
1.31
1
60
0
0.0
5
- 1.
32
190
83 +
12
~ l
NG
C 6
82
6
L
18.4
95
80
0
0.1
0
- 0
.99
16
0
84
- 3
~ 1
NG
C
70
27
*
M
16.6
92
10
00
5
(4)
- 1.
20
10
00
0
.06
-
1.19
5
0
86
- 8
~
Hu
1-2
I
17.4
88
1500
1
- 1.
44
33
00
0
.08
-
1.11
4
60
88 -
1
~ 1
NG
C
70
48
I
19.6
61
19
00
3
(2)
- 0
.24
1
40
0
0.4
3
- 0
.37
3
0
89
+
0 ~
1 N
GC
7
02
6
I 1
8.3
82
2
20
0
4 (3
) -
0.7
0
1800
0
.16
-
0.8
0
0
89 -
5
~ 1
IC 5
11
7
L
16.3
33
24
00
2
(2)
- 1.
73
12
00
0.
01
- 2
.06
10
0
Tabl
e IV
(co
ntin
ued)
Nam
e M
ass
- lo
gZ
In
dep
end
ent
dis
tan
ce
clas
s (W
m-Z
Hz
-1)
E -
D d
eter
min
atio
ns
PK
O
ther
s d
(pc)
W
eig
ht
log
D
d (p
c)
D
(pc)
lo
gD
Z
(p
c)
1 2
3 4
5 6
7 8
9 10
11
93 +
5
~ 1
NG
C
7008
* I
19.7
76
1000
3
(2)
- 0.
36
1300
0.
47
- 0.
33
110
93
+
1~
M
1-7
8
I 18
.921
77
0 0.
25
-0.6
1
10
95 +
0
~ 1
K 3
-62
?
t7.6
35
2
00
0
0.05
-
1.30
0
95 -
2
~ 1
M
2-4
9
L
16.7
04
20
00
0.
01
- 1.
83
80
96 +
29
~ 1
NG
C
6543
L
17
.954
57
0 0.
05
- 1.
27
27
0
96
+
1~
K4
-45
9
16.8
68
28
00
0.
02
1.73
4
0
t~
10
0-
5 ~
1 IC
521
7 L
17
.817
12
00
1 -
1.40
15
00
0.06
-
1.23
14
0 >
10
0-
9~
M
e2-2
I
16.7
43
50
00
0.
03
- 1.
53
700
x
104
+ 7
~ i
NG
C
7139
I
20
.54
2
20
00
3
(2)
- 0.
12
21
00
0.
83
- 0.
08
26
0
t,
10
6-
17~
N
GC
76
62*
L
18.0
62
60
0
5(3
) -
1.24
73
0 0.
07
- 1.
14
22
0
107
+ 2
~ i
NG
C
7354
* I
18.2
75
20
00
5
(3)
- 0.
63
1300
0.
15
- 0.
84
40
r~
10
7-
2~
M
1
-80
M
18
.902
9
60
0
0.35
-0
.46
34
0
111
- 2
~
Hb
12
I 16
.266
35
00
0.01
-
1.88
I2
0
"~
;=
11
8-
8~
Vy
1-1
L
18
.221
3
20
0
0.08
-
1.09
4
40
11
8 -
74 ~
1
NG
C
246
An
2
0.6
23
57
0 4
(3)
- 0.
18
41
0
0.48
-
0.32
4
00
>~
r-
1
19
- 6
~
Hu
1-1
I
18.4
33
68
00
0.
17
-0.7
8
73
0
> x 1
20
+
9~
N
GC
40
I
18.6
98
700
1 -0
.91
11
00
0.20
-0
.69
17
0
123
+ 34
~ 1
IC
356
8 L
18
.358
17
00
0.09
-
1.04
9
40
13
0+
1~
IC
174
7"
I 18
.419
2
40
0
5(3
) -0
.82
2
60
0
0.16
-0
.79
4
0
130
- t0
~ 1
N
GC
6
50
-1
An
2
0.1
24
12
00
1 -
0.26
74
0 0.
34
- 0.
47
130
13
0-
11~
M
1
-1
I 18
.150
4
50
0
0.13
-0
.87
86
0
13
8+
2
~
IC2
89
I
19.1
28
25
00
3
(2)
-0.3
6
1600
0.
28
-0.5
5
50
144
+ 6
~ 1
NG
C
1501
I
19.4
35
1300
1
- 0.
46
1300
0.
36
- 0.
45
140
14
7-
2~
M
1
-4
M
17.7
15
62
00
0.
15
-0.8
2
20
0
148
+ 57
~ 1
N
GC
3
58
7
An
20
.713
4
60
1
- 0.
36
45
0
0.49
-
0.31
38
0
159
- 15
~ 1
IC
351
I
18.4
83
46
00
0.
17
- 0.
76
1200
161
- 14
~
IC 2
003
I 18
.288
4
40
0
0.13
-0
.83
11
00
Tabl
e IV
(co
ntin
ued)
Na
me
M
ass
-
log
E
Ind
ep
en
de
nt
dis
tan
ce
Z -
D
de
term
ina
tio
ns
clas
s (W
m-
2 H
z -
i )
PK
O
ther
s d
(pc)
W
eig
ht
log
D
d (p
c)
D
(pc)
lo
gD
Z
(p
c)
1 2
3 4
5 6
7 8
9 10
11
165
- 15
~ 1
N
GC
1
51
4'
L
19.9
88
60
0
3 (2
) -
0.4
7
61
0
0.3
4
- 0
.46
16
0
166
+ 1
0 ~
1 IC
21
49
L
17
.979
9
00
1
- 1.
33
1300
0
.07
-
1.17
2
20
16
9-
0~
IC
21
20
?
19.5
65
1200
0.
25
-0.6
1
0
17
1-2
5~
B
a 1
L
20
.33
4
24
00
0
.46
-0
.34
1
00
0
174
- 14
~ 1
H
3
-29
I
19.4
26
43
00
0
.36
-
0.4
4
1050
17
8-
2 K
3
-68
L
19
.362
4
10
0
0.2
0
- 0
.68
14
0
18
4-
2~
M
1
-5
L
16.9
99
23
00
0
.02
-
1.65
7
0
189
+ 1
9 ~
1 N
GC
23
71
-2
An
19
.787
5
00
1
- 0.
91
95
0
0.23
-
0.63
2
80
18
9+
7
~
M
1-7
" A
n
19
.t5
2
25
00
2
(1)
-0.9
2
28
00
0.
11
-0.9
4
33
0
190
- 17
~ 1
J
32
0
L
18.7
68
29
00
0.
13
- 0
.89
8
60
19
3-
9~
H
3-7
5
L
19.9
53
26
00
0
.34
-0
.47
4
10
194
+
2 ~
1 J
900*
I
18.2
05
32
00
3
(2)
- 0.
81
29
00
0
.14
-
0.8
6
100
196
- 10
~ 1
N
GC
20
22
L
18
.926
15
00
1 -
0.8
3
1500
0.
15
- 0
.84
2
50
196
- 12
~ 1
A
11
L
2
0.2
20
2
90
0
0.4
2
- 0
.38
6
00
19
7+
17
~
NG
C 2
39
2"
L
19.1
88
70
0
3(3
) -0
.81
8
20
0
.18
-0
.74
2
40
197
- 2
~ 1
V-V
1-4
?
19.9
33
53
0
0.3
4
- 0
.48
2
0
19
8-
6~
A
12
?
19.8
46
18
00
0
.32
-0
.51
18
0
20
4 +
4
~ 1
K 2
-2
I 2
1.7
63
9
50
2
.00
+
0.3
0
60
20
5 +
14
~ 1
YM
29
A
n
21
.32
9
22
0
0.6
6
- 0
.18
6
0
20
6 -
4
0 ~
1
NG
C
1535
L
18
.621
15
00
1 -
0.8
4
1200
0.
11
- 0
.94
7
60
21
0+
1
~
M
1-8
M
19
.349
4
80
0
0.4
9
-0.3
1
80
211
- 3
~
M
1-6
L
17
.019
2
20
0
0.0
2
- 1.
63
110
21
2+
4
~
M
1-9
L
17
.408
3
80
0
0.0
4
- 1.
42
26
0
21
4+
7
~
A2
0
L
20
.75
9
21
00
0
.65
-0
.18
2
50
215
+
3 ~
1 N
GC
23
46
M
19
.848
10
00
5 (3
) -
0.55
2
60
0
0.7
2
- 0
.14
14
0
215
- 24
~ 1
IC
41
8
L
17.2
95
33
0
1 -
1.68
5
30
0.
03
- 1.
49
22
0
215
- 30
~ 1
A
7
I 2
1.5
88
4
90
1.
89
+ 0
.28
2
50
>
'z
>
.t-
Tabl
e IV
(co
ntin
ued)
Nam
e M
ass
- lo
g Z
In
dep
end
ent
dis
tan
ce
Z -
D
det
erm
inat
ion
s cl
ass
(Wm
-2
Hz
-1 )
PK
O
ther
s d
(pc)
W
eig
ht
log
D
d (p
c)
D
(pc)
lo
gD
Z
(p
c)
1 2
3 4
5 6
7 8
9 10
11
21
7+
14
~
A2
4
An
2
1.6
26
51
0 0.
76
-0.1
2
130
220
- 53
~ 1
N
GC
13
60
L
20.8
53
550
1 +
0.07
33
0 0.
70
- 0.
15
270
221
- 4
~
A
17
? 21
.052
4
00
0
0.83
-0
.08
2
80
221
- 12
~ 1
IC
21
65
" I
17.8
31
24
00
2
(2)
- 1.
02
26
00
0.
10
- 0.
98
540
223
- 2
~ 1
K
1-8
?
20.2
53
1100
0.
43
- 0.
36
40
22
6+
5
~ 1
M
1-1
6
I 17
.773
6
90
0
0.10
-
1.00
61
0
227
+ 33
~ 1
A
32
L
21
.22
0
1600
0.
95
- 0.
02
850
228
+ 5
~ 1
M
1-1
7
L
17.8
98
43
00
0,
06
- 1.
20
370
23
1+
4
~
NG
C
2438
I
20.0
12
1500
1
-0.2
9
1600
0.
55
-0.2
6
110
23
2-
1~
M
1-1
3
? 18
.999
31
00
0.15
-0
,81
50
233
- 16
~ 1
A
15
L
19
.986
2
10
0
0.35
-
0.46
57
0
23
4 +
2
~ 1
NG
C
2440
* M
1
82
07
2
20
0
4 (3
) -
0.46
18
00
0.30
-
0.52
60
23
6+
3
~
K
1-1
2
? 20
.426
2
70
0
0.50
-0
.30
14
0
23
8+
34
~
A3
3
I 21
.781
17
00
2.29
+
03
6
97
0
239
+ 13
~ 1
N
GC
2
61
0
I 19
.968
2
50
0
0.54
-
0.27
59
0
241
+ 2
~
M
3-4
?
19.3
42
31
00
0.
20
-0.6
9
100
242
- 11
~ 1
M
3
-1
I 18
.984
4
60
0
0.25
-
0.60
88
0
243
- 1
~ 1
NG
C
24
52
I
19.1
10
3600
3
(2)
- 0.
44
30
00
0.
28
- 0,
56
50
24
5+
1~
M
3-5
?
18.5
76
32
00
0.
11
-0.9
6
50
25
2+
4
~
K
1-1
?
20.5
69
24
00
0.
56
-0.2
5
170
25
4+
5
~
M
3-6
I
18.2
70
29
00
0.
15
- 0.
84
25
0
25
9-
0~
H
e2-9
?
17.3
80
1700
0.
04
- 1.
44
0
261
+ 32
~ 1
N
GC
32
42*
L
18,5
13
500
3 (2
) -
1.02
54
0 0.
10
- 0.
98
29
0
261
+ 8
~
NG
C2
81
8"
M
20.1
45
35
00
2
(I)
-0.0
7
3800
0.
91
-0.0
4
53
0
26
1+
2
~
He
2-1
5
? 18
.847
14
00
0.14
-0
,86
50
263
- 5
~ 1
PB
2
L/I
17
.618
33
00
0.05
-
1.33
2
80
264
- 8
~ 1
He
2-7
I
18.8
22
3500
0.
22
- 0.
65
49
0
Tab
le I
V (
cont
inue
d)
Na
me
M
ass
-
log
Z
Ind
ep
en
de
nt
dis
tan
ce
E -
D
d
ete
rmin
ati
on
s cl
ass
(Wm
2
Hz
-l)
PK
O
ther
s d
(pc)
W
eigh
t lo
gD
d (p
c)
D (
pc)
logD
Z
(pc
)
1 2
3 4
5 6
7 8
9 10
11
26
4-
12~
H
e2
-5
L
17.7
58
38
00
0
.06
-
1.25
13
00
26
5 +
4
~ 1
NG
C 2
79
2
L
18.4
01
23
00
3
(2)
- 0
,84
15
00
0.1
0
- 1.
02
100
26
9-
2 ~
l P
B 3
?
18.1
11
22
00
0
.07
-
1.13
12
0
27
2+
12
~
NG
C
31
32
A
n
19.4
51
70
0
5(3
) -0
.69
6
10
0
.16
-0
.79
13
0
27
4+
2
~
He
2-3
5
? 18
.128
3
90
0
0.0
7
-1.1
2
140
27
5-
2~
H
e 2
-28
?
18.9
65
31
00
0
.15
-0
.82
11
0
27
5-
2~
H
e 2
-29
?
19.0
44
28
00
0
.16
-
0.7
9
90
275
- 4
~ 1
PB
4
I 18
.449
3
50
0
0.1
7
- 0
.77
2
20
27
5-
4~
H
e 2
-21
L
1
7.8
22
5
00
0
0.0
6
- 1.
23
35
0
27
7-
3 ~
1 N
GC
28
99
M
2
0.3
79
2
10
0
1.09
+
0.0
4
110
27
8+
5
~
PB
6
I 1
8.8
72
4
40
0
0.23
-0
.64
3
90
278
- 5
~ 1
NG
C 2
86
7
I 18
.205
14
00
1 -
0.9
9
19
00
0
.14
-
0.8
6
170
27
8 -
6
~ 1
He
2-2
6
I 19
.846
2
70
0
0.4
9
- 0.
31
38
0
27
9-
3~
H
e 2
-36
I
18
.31
2
20
00
1
-1.0
2
30
00
0.
15
-0.8
2
160
281
- 5
~
IC 2
501
L
16.4
51
1400
1
- 1.
87
1100
0.
01
- 1.
98
90
28
3+
2
~
My
60
?
18.2
26
23
00
0
.08
-1
.09
8
0
285
- 2
~ 1
He
2-4
7
L
16
.99
0
1500
0
.02
-
1.65
6
0
28
5-
5 ~
1 IC
25
53
L
1
7.5
06
2
10
0
0.0
4
- 1.
38
190
18.1
91
1800
0.
08
- 1.
10
160
285
- 14
~ 1
IC
24
48
L
18
.299
2
10
0
0.0
9
- 1.
06
50
0
28
6 -
4
~ 1
NG
C
32
11
" L
18
.709
2
00
0
3 (2
) -
0.8
4
17
00
0
.12
-
0.91
12
0
28
8-
2~
P
e 1
-3
? 1
8.6
92
3
20
0
0,1
2
-0.9
2
110
28
8 -
5
~ 1
He
2-5
1
? 1
8.6
97
2
20
0
0.1
2
- 0
.92
2
00
28
9+
7
~
He
2-6
3
L
18.1
41
52
00
0
.08
-1
.12
6
30
28
9-
0~
A
GC
ar
? 18
.931
8
20
0,
15
-0.8
4
0
29
0 +
7
~ 1
Fg
1
? 19
.508
15
00
0.23
-
0.63
19
0
291
- 4
~
1C
26
21
L
1
6.9
30
14
00
0.0
2
- 1.
69
100
Tabl
e IV
(co
ntin
ued)
Nam
e M
ass
- lo
g Z
In
dep
end
ent
dis
tan
ce
Z -
D
det
erm
inat
ion
s cl
ass
(Wm
-
2 H
z -
1 )
PK
O
ther
s d
(pc)
W
eig
ht
log
D
d (p
c)
D
(pc)
lo
gD
Z
(p
c)
1 2
3 4
5 6
7 8
9 10
11
292
+ 4
~ 1
PB
8
L/I
18
.249
34
00
0.08
-
1.08
2
40
29
2+
1~
N
GC
36
99
M
19.7
76
30
00
0.
68
-0.1
7
40
29
2+
1
~
He2
-67
?
18.0
51
29
00
0.
07
- 1,
15
50
29
4+
43
~
NG
C
4361
I
19.9
35
1400
1
-0,1
8
1100
0.
52
-0.2
8
74
0
29
4 +
4
~ 1
NG
C
39
18
" I
17.6
90
20
00
2
(1)
- 0.
83
1300
0.
09
- 1.
03
80
29
6-
3 ~
1 H
e 2
-73
?
17.5
89
23
00
0.
04
- 1.
35
120
296
- 20
~ 1
N
GC
31
95
I 19
.926
2
80
0
0.52
-
0.28
9
30
298
- 0
~ 1
He
2-7
7
L
17.6
46
42
0
0.05
-
1.31
0
298
- 4
~ 1
NG
C
4071
M
20
.531
14
00
1 -
0.33
3
60
0
1.22
+
0.08
2
50
30
0-
2 ~
1 H
e 2
-86
?
17.2
82
1900
0.
03
- 1.
49
60
303
+ 40
~ 1
A
35
I 2
1.8
42
36
0 2
(1)
+ 0.
23
44
0
2.09
+
0.32
2
90
30
4-
4~
IC
419
1 I
18.3
28
1500
1
-0.9
9
22
00
0.
15
-0.8
2
150
30
6-
0~
T
H 2
-17
A
? 19
.263
16
00
0.19
-0
.72
0
307
- 3
~ 1
NG
C
5189
* I
20.0
31
1500
3
(2)
+ 0.
05
750
0.56
-
0.25
30
307
- 4
~ 1
My
Cn
18
I
17.7
97
1700
1
- 1.
31
36
00
0.
10
- 0.
99
25
0
308
- 12
~ 1
H
e 2
-10
5
L
20
.20
8
25
00
0.
42
- 0.
38
510
309
- 4
~ 1
He
2-9
9
? 19
.545
2
70
0
0.24
-
0.62
19
0
309
+ 4
~
NG
C
5315
I
17.0
96
26
00
2
(1)
- 1.
14
1700
0.
05
- 1.
31
120
31
0-
2 ~
I H
e 2
-10
3
? 19
.613
2
60
0
0.26
-
0.59
9
0
31
1+
2
~
He
2-1
02
?
18.6
56
27
00
0
.I2
-0
.93
10
0
312
+ 10
~ 1
N
GC
53
07
L
18.4
89
1700
0.
10
- 0.
99
29
0
31
2-
1 ~ 1
H
e 2
-10
7
? 18
.453
2
00
0
0.10
-
1.00
4
0
31
5-
13~
H
e 2
-13
1"
L
17.3
80
800
3(2
) -
1.60
12
00
0.04
-
1.44
2
70
31
6+
8
~
He
2-1
08
L
18
.830
2
60
0
0,13
-0
.87
3
50
31
7-
5~
H
e 2
-11
9
? 19
.691
11
00
0.27
-0
.56
10
0
318
+ 41
~ 1
A
36*
L
2
1.2
40
50
0 3
(2)
+ 0.
04
45
0
0.97
-
0,01
2
90
31
8-
2~
H
e 2
-11
4
? 2
0.1
79
2
80
0
0.41
-0
.39
10
0
Tabl
e IV
(co
ntin
ued)
Nam
e M
ass
- lo
gZ
In
dep
end
ent
dist
ance
Z
-D
det
erm
inat
ion
s cl
ass
(Wm
-
2 H
z -
1)
PK
O
ther
s d
(pc)
W
eigh
t lo
gD
d (p
c)
D (
pc)
logD
Z
(pc
)
1 2
3 4
5 6
7 8
9 10
11
319
+ 15
~ 1
IC
44
06
I
19.1
25
1900
0.
26
- 0.
53
49
0
32
0-
9 ~
1 H
e 2
-13
8
L
18.0
75
22
00
0.
07
- 1.
14
330
321
+ 2
~ 1
He
2-1
15
L
17
.027
17
00
0.02
-
1.63
60
321
+ 2
~
He
2-1
17
?
17.2
37
1300
0.
03
- 1.
51
40
32
1+
1~
H
e 2
-12
0
? 19
.761
2
00
0
0.29
-0
.54
40
321
- 16
~
He
2-1
85
L
19
.011
3
20
0
0.16
-0
.81
89
0
17.9
65
45
00
0.
07
- 1.
18
1300
3
22
- 0
~ !
Pe
2-8
?
16.6
74
1800
0.
01
- 1.
85
0
32
2-
2~
M
z 1
? 19
.359
15
00
0.21
-0
.68
50
3
22
- 5
~ 1
NG
C
5979
L
/I
18.0
04
1500
2
(1)
- 1.
22
1700
0.
07
- 1.
17
150
323
+ 2
~ 1
He
2-1
23
L
17
.550
3
50
0
1 -
1.13
2
10
0
0.04
-
1.36
70
323
- 2
~ 1
He
2-1
32
L
19
.379
2
40
0
0.21
-
0.68
80
32
4+
2
~
He
2-1
25
?
17.0
74
1700
0.
02
-1.6
2
60
32
4-
1~
He
2-1
33
L
17
.148
15
00
0.03
-1
.56
20
325
+ 3
~ 1
He
2-1
29
?
17.0
74
3400
0.
02
- 1.
61
180
32
5-
4~
H
e 2
-14
1
? 18
.838
2
00
0
0.14
-0
.87
14
0
327
+ 10
~
NG
C
5882
L
18
.041
11
00
1 -
1.12
11
00
0.07
-
1.15
19
0
32
7-
1~
H
e 2
-14
3
M
17.6
19
5200
0.
13
-0.8
8
90
32
7-
1~
H
e2-1
40
?
17.1
93
22
00
0.
03
- 1.
54
40
32
7-
2 ~
1 H
e 2
-14
2
L/I
17
.516
2
50
0
0.04
-
1.38
90
32
8-
2~
He
2-1
46
L
18
.641
11
00
0.11
-0
.94
4
0
32
9+
2
~
Sp
1
L
20.1
29
1400
1
-0.3
0
1100
0.
39
-0.4
1
40
33
0-
3~
He
2-1
59
L
/I
18.8
68
23
00
0.
14
-0.8
6
150
331
+ 16
~
NG
C
5873
I
18.1
93
47
00
0.
14
-0.8
6
1260
331
- 1~
M
z 3*
M
18
.443
4
00
0
2(1
) -0
.23
16
00
0.25
-0
.61
30
33
1-
2~
H
e 2
-16
1
L
18.7
61
26
00
0.
13
-0.9
0
90
332
- 3
~ 1
He
2-1
64
I
18.6
87
26
00
0.
20
- 0.
70
140
Tabl
e IV
(co
ntin
ued)
Nam
e M
ass
-lo
g Z
In
dep
end
ent
dis
tan
ce
E -
D d
eter
min
atio
ns
- C
lass
(W
m-a
Hz
-1)
PK
O
ther
s d
(pc)
W
eig
ht
log
D
d (p
c)
D (
pc)
log
D
Z
(pc)
1 2
3 4
5 6
7 8
9 10
II
33
3+
1~
H
e2-1
52
L
18
.057
14
00
0.07
-
1.15
20
33
4-
9 ~
1 IC
464
2 L
- 18
.907
18
00
0.14
-
0.84
29
0 3
35
- 1~
H
e 2
-16
9
? 17
.965
17
00
0.07
-1
.18
20
33
6+
1~
P
e 1
-6
? 18
.533
25
00
0.10
-0
.98
40
3
36
- 5~
H
e2-1
86
L
17
.898
43
00
0.06
-
1.20
37
0
33
6-
6~
PC
14
L
18.4
79
3000
0.
10
- 1.
00
310
33
8+
5~
H
e 2
-15
5
? 18
.750
17
00
0.12
-0
.90
15
0 33
8 -
8 ~
1 N
GC
632
6 I
18.6
24
3000
0.
19
- 0.
72
350
341
+ 13
~ 1
N
GC
602
6 L
19
.938
12
00
0.33
-
0.48
29
0
34
1+
5~
N
GC
615
3 I
18.3
52
1700
1
-0.7
0
1300
0.
16
-0.8
0
110
342
+ 17
~ 1
M
e 2
-1
L
18.3
32
2900
0.
09
- 1.
05
1400
3
42
+
0~
NG
C 6
072
M
19.7
10
1800
1
-0.2
6
2100
0.
65
-0.1
9
360
342
- 14
~ 1
S
p 3
L
19.5
69
1400
0.
25
- 0.
61
350
34
5+
0~
IC
463
7 L
18
.154
90
0 0.
08
-1.1
1
0
34
5-
8~
TC
1
L
18.1
21
1600
1
- 1.
12
1600
0.
07
- 1.
12
220
34
6-
8~
IC 4
663
L/I
18
.929
21
00
0.14
-0
.84
28
0 34
8 -
13 ~
1
IC 4
699
L
18.6
20
3500
0.
11
- 0.
94
770
34
9+
4
~
M2
-4
L
16.9
19
3500
0.
02
- 1.
70
230
34
9+
1~
N
GC
63
02
" M
16
.723
17
00
3(2)
-
1.11
15
00
0.07
-
1.18
20
3
49
- 1~
N
GC
633
7 I
19.6
25
1800
0.
42
-0.3
8
30
35
0+
4~
H
2-1
L
17
.917
23
00
0.06
-
1.20
16
0
35
1+
5~
M
2-5
L
18
.391
48
00
0.09
-1
.02
43
0 3
53
+
6~
M
2-6
L
16
.944
47
00
0.02
-
1.68
50
0 3
54
+
4~
M
2-1
0
L/I
17
.470
70
00
0.04
-
1.39
49
0
35
5-
2~
H
1
-32
L
16
.254
27
00
0.00
8 -2
.10
90
3
55
- 2
~
H
1-31
L
/I
16.2
44
4100
0.
008
-2.1
1
140
35
5-
4~
M
1
-30
17
.419
37
00
0.04
-
1.42
26
0
Tabl
e IV
(co
ntin
ued)
Nam
e M
ass
- lo
g I2
In
dep
end
ent
dis
tan
ce
Z -
D d
eter
min
atio
ns
clas
s (W
m -
2 H
z -
1 )
PK
O
ther
s d
(pc)
W
eig
ht
log
D
d (p
c)
D
(pc)
lo
gD
Z
(p
c)
1 2
3 4
5 6
7 8
9 10
11
35
5-
6~
M
3
-21
L
18
.187
3
30
0
0.08
-
1.10
34
0
356
- 4
~ 1
Cn
2-1
L
17
.248
2
60
0
0.03
-
1.50
19
0
35
6-
4~
H
1
-41
L
/I
19.0
69
24
00
0.
16
-0.7
9
170
35
6-
5~
M
2-2
4
L
19.2
81
44
00
0.
19
-0.7
1
380
35
7+
7~
M
4-3
I
16.5
69
64
00
0.
02
-1.6
5
750
35
7+
3~
M
3-7
L
18
.484
3
10
0
0.10
-0
.99
16
0
357
+ 3
~
M
3-4
1
? 17
.678
2
50
0
0.05
-
1.28
13
0
357
+ 2
~
H
1-1
8
I 16
.606
4
90
0
0.02
-
1.68
17
0
357
+ 1 ~
1
H
1-2
3
L
16.9
50
33
00
0.
02
- 1.
68
60
35
7-
4~
H
1
-42
L
/I
18.2
20
28
00
0.
08
- 1.
09
190
358
+ 5
~ 1
M
3-3
9
? 18
.397
9
60
0.
09
- 1.
02
90
35
8+
4
~
M3
-8
L
18.3
31
3300
0.
09
-1.0
5
220
358
+ 3
~ 1
M
3-1
0
L/I
17
.873
3
50
0
0.06
-
1.21
19
0
35
8+
3
~
TH
3-1
9
L/I
16
.153
4
00
0
0.0
07
-2
.17
2
10
358
+ 3
~
H
1-2
0
L
17.9
01
28
00
0.
06
- 1.
20
150
35
8+
1~
M
4-6
L
16
.726
2
80
0
0.02
-
1.82
50
3
58
- 0
~
M
1-2
6"
I 17
.020
18
00
3(2
) -
1.43
2
10
0
0.04
-
1.36
0
358
- 7
~ 1
NG
C
6563
* A
n
19.7
16
60
0
3 (2
) -
0.87
9
70
0.
22
- 0.
66
120
35
9+
15~
A
40
L
20
.431
33
00
0.50
-0
.30
84
0
35
9+
5
~
M
3-9
L
/I
19.2
61
23
00
0.
19
- 0.
72
190
35
9-
0~
H
b5
M
18
.129
2
00
0
3(2
) -0
.69
19
00
0.19
-0
.71
0
359
- 1 ~
M
3
-44
?
17.3
66
35
00
0.
04
- 1.
44
60
35
9-
2~
H
1
-40
L
16
.465
3
10
0
0.01
-
1.98
11
0
35
9-
4~
M
2
-27
L
16
.795
2
60
0
0.02
-
1.77
19
0
PN
ca
lib
rato
rs a
re d
esig
nat
ed b
y *
,
O)
0
Fig. 9.
_
PLANETARY NEBULAE IN THE GALAXY
I
65
�9 \ \ .
I I I \ "
- 2 - 1 0 log D
T h e d e p e n d e n c e o f n e o n t h e d i a m e t e r D for l o w - m a s s P N e . L i n e 1 c o r r e s p o n d s to t he filling f a c t o r
e = 1, for l ine 2 e = 0.2.
Theoretical E(D)-dependences for the L-type PNe can be obtained using the known models of PN expansion and evolution and CS evolution (Wood and Faulkner, 1986; Volk and Kwok, 1985; Iben, 1984; Spergel et al., 1983; Schmidt-Voigt and K~Sppen, 1987a, b). Volk and Kwok (1985) calculated the PN expansion models with CS masses 0.57, 0.60, and 0.64 M e. According to our classification these CS are classified as L- and the I-type.
The physical picture of PN formation and evolution is as follows. At the AGB stage
the star loses the mass by means of stellar wind with constant rate ~ / a n d velocity V o. Volk and Kwok (1985) thought that the outflow time is equal to 105 yr. A shell is formed, its size being 0.1 (V o km s - 1 ) p c with the mass distribution n ,-~ r -2 where n is the number density of particles, where r is the distance from CS to shell. Then the wind stops, a CS is formed and there is no outflow during a certain time t o. For this time the CS heats from 5 x 103 to 3 x 104 K, afterwards the fast wind stage with intensing mass
loss rh and high-velocity Vw begins; moreover, V w ,> Vo; rh ~ ~/. The matter of the fast wind reaches the inner boundary of the shell thrown away at the AGB stage. Here the shock wave is formed. Along the matter of the shell which is compressed by the fast wind ionization front is spread. The value of rh is calculated by the Reimers formula at r/= 1; Volk and Kwok (1985) accepted t o -- 1500 yr.
The comparison of model Z(D)-dependences with the observed one allows to not only estimate the mean velocities of the matter losses by stars at the AGB stage (for the
66
h0 O r-I
- 1
- 2
J
P. R. AMNUEL ET AL.
I
- 3 I 1
- . 5 - 1 . 0 - 0 , 5 0 l o g D
Fig. 10. The dependence of PN mass Mpn on the d iamete r D according to the Z(D)-dependences for PNe
of different mass types at e, cor responding to these mass types of PNe (see the text). 1 - M-type PNe,
2 - I- type PNe, 3 - L-type PNe.
L-type PNe ()k/) ,,~ 6 x 1 0 - 6 M o yr -1) but also compare PN ages obtained by the
models of Volk and Kwok (1985) from the moment AGB wind stops with kinematic
PN ages tki n = D/Vex p where Vexp is taken constant (from observations), and the value
of D is taken from observations. We should note that when D < 0.3 pc tki n is, in this
case, the lower limit of PN age since PN expansion velocity V~• (see, e.g., Amnuel et al.,
1984) increases with the growth of D. This is confirmed by observational data too
(Sabbadin and Hamzaoglu, 1981). The real kinematic age can be ~ 1.5 times larger than
the calculated one at V~x p = const.
Table V shows the values of kinematic age tk i n and theoretical t~=_ D for the L-type
calibrators at the CS mass 0.57 Mo, the agreement between ages being good. In two
cases (PK 65 - 27 ~ 1 and PK 286 - 4 o 1) there are no measured values of Vex p, and tki n is not determined. From model tz_~9 for these PNe the probable values of V~x p = 12 km s - t and 14 km s - 1 were obtained, respectively. We should note that the
smaller the measured Vexp the better coincide ages.
PLANETARY NEBULAE IN THE GALAXY
TABLE V
67
PK name V~p tki n tz - D 3 ) / D
(km s -1) (103 yr) (103 yr) (10-6Moyr 1) (pc)
11- 0~ 18.2 1.9- 2.8 2.5 7 0.07 29- 5"1 28.8 2.5- 3.8 5 4 0.15 65 - 27 ~ 1 (12.0) - 2 10 0.05
106- 17~ 25.7 1.1- 1.6 2 5 0.06 165 - 15 ~ 1 25.1 6.6-10 10 6 0.34 197+ 17~ 53.7 1.4- 2.1 5 4 0.16 261 + 32 ~ 1 15.1 3.1- 4.6 3.1 5 0.10 286- 4~ (14.0) - 5 7 0.14 315 - 13 ~ 1 (10.2) - 1.2 7 0.02 318 + 41 ~ 1 36.3 15-22.5 30 10 1.10
The values Ve• = D/tz_ D are in brackets.
It follows from Table V that for the L-type PNe at the mean CS mass 0.55-0.57 M o
the mean outflow value (3;it) ~ 6 x 10 - 6 M o y r - 1. At outflow duration ~ 105 yr the
ejected shell reaches the mass ~ 0.6 M o , which agrees with the above-given value of
P N mass. However, this value should be accepted with care, since the real value of
outflow time at AGB stage is unknown. F rom Figure 10 it follows only that it is most unlikely to be less than 5 x 1 0 4 yr.
The comparison of models with observations allows to conclude that the L-type PNe
have a weak halo. In fact, in the model of Volk and Kwok (1985) the ionization front
for the time ~ 103 yr reaches the boundary of the matter compressed by the shock wave.
In such a case, the ionization of the more rarefied part of red giant's wind before the
shock wave front begins and in the density of the matter within wind is enough, then
an emission should be obtained (halo). At present the haloes are detected in 6 L-type
PNe at 0.05 pc < D < 0.2 pc, corresponding to t~ -D ~ (2-3) x 103 yr.
Figure 11 shows the dependence of F'/F on D for the L-type PNe where F ' and F
are, respectively, the ultraviolet photon numbers of Lyman continuum which are emitted
by the central star (s - 1 ), and the number of photons necessary for ionizing the visible
shell of PNe. The number of photons emitted by the CS at D > 0.05 pc is more than
the number of photons necessary for ionization. Though the scatter of the values is large,
an increase ofF'IF with the diameter (and with P N age) is nevertheless observed, which
corresponds to the CS evolution to the left of the L - T diagram (Figure 1). The
dependence o f F'/F on D was studied earlier by AmnueI et aL (1985). The boundary of
halo arising in the L-type PNe (Figure 11) corresponds to F'/F = 1 which concludes about using the models of Volk and Kwok (1985).
The possibility of determining D by the Y(D)-dependence allows to consider the shape
of CS evolution at the L - T diagram by observational data. Thus, there are independent
determinations of Tet r for 39 L-type CS, for them by the E(D)-dependence the values
o f d and L are determined. These PNe were classified in 6 groups in order of the growth
68 P . R . AMNUEL ET AL.
Fig. 11.
1.5
hO o
I - I
1 ,0
0 .5
- 0 . 5
| I 1 ! - - I
Q Q
I �9 l
Q
�9 /
I I i i I
- 2 - 1 0 l o g D
The dependence of log(F' IF) on the logD for L-type PNe. Vertical dashed lines limit the region where halo exists.
of D - i.e., with the increase of age. The averaged data by L, Tefr, D, tk~ n are given in Table VI. Figure 12 shows the evolutionary track of the L-type CS determined by these
data. The evolution occurs at almost constant L toward the increase of T , at
( M ) c , ~ 0 . 5 5 M e which does not contradict the P N evolution models. The mean
lifetime of the L-type PNe until their diameter reaches D ,-, 1 pc is tki . ~ 1.5 X 104 yr.
We should note that t = 1.5 x 104 yr is the time during which the L-type CS can make a loop at the L - T diagram as a result of helium flash (Iben, 1984). Apparently, as it was
considered by Amnuel et al, (1984), all evolution of the L-type PNe occurs during such
flash (i.e., inside the loop).
PLANETARY N E B U L A E I N THE GALAXY
TABLE VI
69
log D log T log L t k ~ N (103 yr)
< - 1.5 4.59 _+ 0.15 3.10 + 0.28 1.2 3 - 1.5 --<logD < - 1.1 4.61 _+ 0.11 3.27 + 0,2l 1.2- 2.8 8 - 1.1 --< logD < -0 .9 4.74 • 0.13 3.29 • 0.28 2.8- 4.3 9 -0 .9_<logD < -0 .5 4.73 _+ 0.17 3.12 i 0.21 4.3- 7.4 6 - 0.5 -< logD < - 0.1 4.94 + 0.11 3.07 _+ 0.25 7.4-14.8 6
> -0.1 4.92 + 0.08 3.34 • 0.37 14.8-29.4 7
0 r-I
3
I I
0.6
3 2
_J
IL .. 4--
0 . 5 5 4
0.55
2
1 I
5.0 4.5 4.0 log
Fig. 12. The averaged empirical evolutionary track for L-type PNe CS. The evolution goes from region 1 to region 6, one can see the average L and T and corresponding ages for these regions at Table VI. The theoretical tracks of the masses equal to 0.554 Me, 0.6 Me, 0.8 M o (solid lines) and 0.55 M e (dashed line)
are shown.
70 P.R . AMNUEL ET AL.
Thus the observational data on the L-type PNe on the whole agree well with the model
of Volk and Kwok (1985). However, it should once more be noted that, because of the
difference in evolution time of CS and PNe, the models of the late-stages of evolution
of low-mass stars need to be considerably revised. Let us consider the distribution of the L-type PNe in the Galaxy. In order to determine
the scale-height/~, it is necessary to know the maximum distance d till which one can
neglect the selection and at which practically all PNe within this volume are observed.
For the L-type PNe the value of d can be determined not only totally but for PNe with
different diameter as well:
l o g D < - 1 . 5 , d = 2 5 0 0 p c ,
- 1 . 5 < l o g D < - 1 . 1 , d = 1700pc,
- 1 . 1 < l o g D < - 0 . 9 , d = 1600pc,
- 0 . 9 < l o g D < - 0 . 1 , d = 1200 pc ,
l o g D > - 0 . 1 , d = 500 pc .
In order to estimate/~ let us take the L-type PNe with logD < -0 .1 to the distance
1200 pc (besides the L-type PNe we use also the L/I-type and type '?'). There are
31 PNe of such type in all their scale-height/~ = 220 + 10 pc.
The local number density of the L-type PNe (types L, L/I, and ?) is ao = 6.4 + 1.4 kpc 2. The local spatial density in this case is Po = 29.0 + 7.7 kpc - 3.
Let us determine the radial distribution of the L-type PNe in the Galaxy by the method suggested by Amnuel et al. (1984), calibrating the distribution at a 0 = 6.4 k p c - 2. If we express the distribution as p = Pc x 10- m R - l l Z l, where R and Z are, respectively, the
distance to the galactic center and that to the galactic plane then we have
1 = 0.218 + 0.023 and m = 1.98 + 0.09. The total number of the L-type PNe in the Galaxy N ~ 2.9 x 104. This, of course, is a rough estimate; since the value of m and l
change within the Galaxy. For determining the birthrate of the L-type PNe we use those within 1200 pc selecting
among them the PNe with logD < - 0.5 (this corresponds to the age of up to 104 yr).
Their ao = 5.08 + 1.06 kpc -2 ; hence,
vlo o= (2.3 x 0.7) x 10-12 p c - 3 y r - 1
The total PN of the L-type birthrate is, in this case, v L ~ 2.3 y r - 1
5. Massive Nebulae (M-Type)
Unlike the L-type, those of PNe M-type are not numerous. However, we succeeded in selecting among them 9 calibrators with well enough determined distances. Only those PNe were chosen whose mass index K > + 0.6 at 5 or more criteria. As calibrators we used PNe N G C 2440, N G C 2818, N G C 6302, N G C 6537, N G C 6563, N G C 6741, N G C 6853, N G C 7027, and Mz 3. Let us consider them as they are given in Table IV.
PLANETARY NEBULAE IN THE GALAXY 71
N G C 6 5 3 7 ( P K 10 + 0 ~ i) . Its distance was determined by the method 3 (Gathier et al.,
1986), d = 2400 pc. Taking 0 -- 10" and ( $ 5 ) = 624 mJy (Calabretta, 1982; Isaacman,
1984) we obtain D = 0.119 pc an logi2 = - 17.488.
N G C 6741 (PK 3 3 - 2 ~ 1). The distance was determined by the methods 3 and 4
(Gathier et al., 1986; Kaler and Lutz, 1985; Acker, 1978). Like Sabbadin (1986) we took d = 1700 pc. Taking 0 = 8': 3 and ( S 5 ) = 187 mJy (average value of two observations by Aller e ta l . , 1985), we obtain D = 0.117 pc and logZ = - 17.832.
N G C 6853 (PK 60 - 3 ~ 1). This PN is one of the nearest and largest PNe. Its distance was estimated by the methods 2-5 (for details, see Sabbadin, 1986a). There are
considerable differences in determinations of 0: from 200" to 480". We accepted
0 = 360". By use &th is value, as well as d = 250 pc we have D = 0.436 pc. Assuming
S 5 = 1325 mJy (Phillips, 1984) we have logZ -- - 20.256. Though by the majority of its parameters this PN is classified as M-type some of its features allow to select it (as well
as a number of other PNe) into a special group - anomalous PNe. We shall consider these PNe below.
N G C 7 0 2 7 ( P K 8 4 - 3 o 1). Its distance was determined by the methods 2 -5 (Sabbadin,
1986a). At d --- 1000 pc and 0 = 13" we have D = 0.063 pc. The mean measurement of those of Milne (1979), Daub (1982), and Phillips and Pottasch (1984) give ( S 5 ) = 6337 mJy, hence, logZ = - 16.692.
N G C 2440 (PK 234 + 2 ~ 1). The distance was repeatedly determined by the methods
3-5. Like Gathier et al. (1986) we accepted d = 2200 pc which at 0 = 34" corresponds
to D = 0.347 pc. At ( S 5 ) = 416 mJy (Gathier et aL, 1986; Pottasch et aL, 1984) we have logZ = - 18.707.
N G C 2 8 1 8 ( P K 2 6 1 + 8 ~ 1). This PN is situated in the open cluster N G C 2818. Dufour
(1984) discussed in detail the belonging of this PN to the cluster and the distance to the cluster. At d = 3500pc, 0 = 50", and S 5 = 33mJy (Dufour, 1984) we have D = 0.851 pc and logZ = -20.145.
M z 3 (PK 331 - 1 ~ 1). According to the criteria this PN is certainly classified as
M-type. However, there is some doubt about the value of d determined only by one method. According to Acker (1978) d -- 4000 pc. At such distance and at 0 = 30" we
h a v e D = 0.589 pc, and at ( S 5 ) = 607 mJy (Dinerstein, 1980; Pottasch et al., 1984) we
obtain logZ = - 18.443. At the Z - D diagram this PN is situated considerably higher than the rest (Figure 13). This is apparently due to an overestimate of d. The value of d ,-~ 2 kpc is likely to be more correct.
N G C 6302 ( P K 349 + 1 ~ 1). The PN is situated in the open cluster N G C 6334 (Phillips
and Pottasch, 1984). Other values do not contradict the value o fd = 1700 pc either. The determination of 0 is uncertain. We accepted 0 = 9':5 according to Altschuler e ta l .
(1986), Rodriguez et aL (1985). At S 5 = 3150 mJy (Rodriguez et aL, 1985) we obtain D = 0.078 pc and logY. = - 16.723.
N G C 6563 ( P K 358 - 7 ~ 1). This PN, in spite of its being M-type like N G C 6853, is classified as belonging to a special class of anomalous PNe; and will be considered
separately. The principal parameters of this PN are as follows: d = 600 pc (determined by methods 3 and 4, see Sabbadin, 1986a; Acker, 1978), 0 = 46':5, S 5 = 77 mJy (Calabretta, 1982), hence, D = 0.135 pc and logZ = - 19.716.
72 P. R. AMNUEL ET AL.
- 1 7
- 1 8
- 1 9
- 2 0
\ \xB k \ A
k k , \ ,103~\
\
\ \
\
\ \
k
3 10 3 ;Q\
0 7
\x �9 6 \ \ �9 ' \ \
\ \
\ \
\
- 21 I I - 1.5 - 1.0 ,-0.5
5 0
\'~k 103
X \ 1o,\\
0 9 \ \
log D
Fig. 13. The l~(D)-dependence for M-type PNe. Empirical dependence is shown by a solid line. Dashed lines show the model dependences at 2~/= 4 x 10 - s Mo yr - 1. Line A shows the CS mass 0.8 714o, line B shows those with masses 1.2 M o. Filled circles are the normal massive PNe, unfilled ones show the anomalous PNe. Dashed lines show the model ages of PNe. PN designations: 1 - P K 8 4 - 3 ~ 2 - P K 349+ I ~ 1 0 + 0 ~ 1 7 6 PK 331 - l ~ 1 7 6 358-7~
8 - P K 2 6 1 + 8~ 9 - P K 6 0 - 3 ~
T h e Z - D diagram o f the M - t y p e calibrators is s h o w n in Figure 13. T h e P N e
P K 60 - 3 ~ 1 and P K 358 - 7 ~ 1 are s i tuated cons iderably lower, P K 331 - 1 ~ 1 is con-
s iderably higher than six PNe situated on the line
logl~ = - 3 logD - 20.27 ; (7)
PLANETARY NEBULAE IN T H E GALAXY 73
the linear correlation coefficient being 0.96. This dependence is correct within the diameter range 0.05-1 pc.
Figure 13 shows the theoretical tracks of the PN evolution according to the models calculated by Spergel et aL (1983). The physical picture of the PN formation and expansion in this model is as follows. The star at the AGB stage loses mass with constant velocity 20 km s - 1 and rate .~/during 2.5 x 10 4 yr. The matter forms a shell with density distribution ~ r - 2. Then the ejection stops, a CS is formed (in the model
the CS with 0.8 M G and 1.2 M o are considered), which ionizes the matter of the ejected shell. The ionization front moves in the shell outward, and reaches some time later the outer boundary of the shell. Afterwards the PN radius coincides with the outer boundary of the matter ejected at the AGB stage. Inner boundary of the shell continues its outward movement at the same velocity of 20 km s - 1. The shell is not compressed by the shock wave, since the fast wind from the CS is not considered in the model. The model of Spergel et al. (1983) is thus simpler than that of Volk and Kwok (1985) considered above. Figure 13 shows the Z(D)-dependence obtained within the framework of the model of Spergel et al. (1983) for the CS masses 0.8 M o and 1.2 M o at the outflow rate _~/= 4 x 10 - 5 Mo y r - 1. The points corresponding to the times t z_ n since the moment of the M-type CS formation are shown: 300, 103, and 3 x 103 yr. Qualitatively this theory is in agreement with the observational points describing both the value of the slope of the Z(D)-dependence and the absence of changes in this slope in the observed range of D.
We have determined e for the M-type PNe similar by as was done for those of L-type; e turned out to be equal to 0.3 (in some cases e > 1, like for the L-type PNe what is explained by an evident underestimate of the measured values of %). The dependence of e and D is not observed for the M-type PNe either. By use of e = 0.3 one can obtain the M-type PN masses. According to (6) using the E(D)-dependence we obtain approxi- mately logMpn = logD. Thus, at D = 1 pc, the M-type PN has the mass M p , ,,~ 1 M o .
Let us check whether the models of the M-type PN evolution correspond to observa- tions comparing characteristic ages. In this case it is useless to use tkin since the sizes of the M-type PNe not correspond to the expansion of the shell matter but to the expansion of ionization front which during the PN lifetime (according to the observa- tions) does not reach the outer boundary of the shell ejected at the AGB stage.
Let us select among the M-type PNe those for which there are either independent measurements of CS temperature by ultraviolet, or spectral data or these temperatures can be determined by the Zanstra method in the radio range assuming F ' / F = 1
(S tankievich and S harova, 1983; Amnuel et al . , 1985 ). Tee r is determined by independent data only for PN PK 234 + 2 ~ 1. For another five calibrators, Tee r is determined by the Zanstra method. Furthermore, we determine the CS ages by their location at the L - T
diagram and compare them with those of the corresponding PNe at the Z(D)- dependence; we also find the PN ages from the models of Spergel et aL (1983). Table VII gives ages t~_ n and t L _ T which agree with each other within their error limits (for the CS model with mass 0.8 Mo). In two cases, the model of Volk and Kwok (1985) suits better at M = 0.64 M o with the mass loss /s 8 x 10 -5 M o y r - 1. Evidently, for the
74 P. R. AMNUEL ET AL.
T A B L E VII
P K n a m e t z - - D t L ~ T tk in C o m m e n t s (10 3 yr) (10 3 yr) (10 3 yr)
N o r m a l M- type P N e
10 + 0 ~ 1 4 4 5.6 Mcs = 0.64 M e
33 - 2 ~ 1 0 .15 -0 .3 0.01 2.6 0.80 M o
84 - 3 ~ 1 0.25 0.1 1.5 0.80 M o
234 + 2 ~ 1 0.4 0 . 1 - 0 . 2 a 7.3 0.80 M o
261 + 8 ~ 1 30 25 7.8 0.64 M o
331 - 1 ~ 1 0.3 0 . 1 - 3 - 0.80 M o
N o r m a l I - type P N e
2 + 5~ 10 3 -
9 - 5~ 5 10 a 11
2 5 - 17~ 15 20 a 3.8
3 3 - 6~ 20 20 a 23
6 0 - 7 ~ l 2 - 3 2 0 - 3 0 1.9
1 2 0 + 9~ 3 2 a 2 - 3
221 - 12~ 4 - 2.3
3 0 7 - 3~ 20 100 ~ 16
3 5 8 - 0~ 1.2 2 a 1 .6 -3
A n o m a l o u s P N e
3 - 4 ~ 2 8 - I - type
11 + 5 ~ 1 0.6 7 0 - 2 0 0 0.6 I - type
36 - 57 ~ 1 1.5 200 a 11 M - t y p e
6 0 - 3 ~ 1 1 30 a 9 M - t y p e
63 + 13 ~ 1 6 20 a 4.5 I - type
6 9 - 2~ 6 100 2.8 1-type
148 - 57 ~ 1 10 50 a 5.6 1-type
189 + 19 ~ 1 2 70 a 1.4 I - type
189 + 7 ~ 1 2 - 4 200 5 1-type
272 + 12 ~ 1 5 150 7.3 1-type
3 5 8 - 7 ~ 1 0 . 2 - 1 1 0 - 2 5 6 M- type
a The value o f T is d e t e r m i n e d a c c o r d i n g to spec t r a l a n d p h o t o m e t r i c da t a . In o the r cases :
by the Z a n s t r a m e t h o d in r ad io range .
M-type PNe the value of the wind at the AGB stage can on the average be accepted
as ~ / ~ 5 x 10 - s Mo yr - 1. The mean M-type PN lifetime is ~ 3000 yr, the CS mass
0.8 M o. One cannot estimate the duration of the mass loss at the AGB stage and the
total of the matter ejected (at least, t > 2 x 1 0 4 yr and Mshe~ I > 1 Me), since the ioni-
zation front has no time to reach the boundary of the matter ejected from the star.
It is qualitatively clear that, from the L-type PNe to those of the M-type, both the mass
of the shell ejected by a red giant and slow wind rate (by a factor of 10), as well as the CS mass, increase. This, in turn, shows that our division of the PNe according to criteria
by mass classes is correct. A total of 27 PNe are classified as M-type (Table III). The analysis (see below) showed that 6 PNe among them are classified as anomalous
PLANETARY NEBULAE IN THE GALAXY 75
objects. Distances to 21 PNe are obtained by Y.(D)-dependence (6) and are given in
Table IV. Distances to 6 anomalous PNe are also obtained by the Z(D)-dependence
which will be considered below (Section 7).
Let us consider the distribution of the M-type PNe in the Galaxy. Since the number
of objects is small, it is practically impossible to determine the selection depending on
the PN diameter. On the average, there is no observational selection for the M-type PNe
up to the distance of ~ 2 kpc. Seven M-type PNe (including anomalous ones) whose
scale height/3 = 120 + 20 pc are situated within 1.5 kpc. The local surface number density of the M-type PNe (without anomalous ones) % = 0.5 + 0.2 k p c - 2 that giving
for the local formation rate of the M-type PNe at mean age ~ 3000 yr
Vloca ~ = (1.4 + 0.6) x 10- 12 p c - 3 y r - 1
The distribution of the M-type PNe does not show any systematic concentration
toward the galactic centre. On the other hand, out of 21 PNe's situated at a distance
of less han 4 kpc form the Sun, at least, 14 are within the galactic arms (mainly in the
local and Scorpio-Centaurus arms) while the expected number of random occurrence
is hardly larger than 7. Evidently, the M-type PNe really concentrate toward the galactic
arms, like normal stars of classes earlier than B. The scale-height of an M-type PNe is consistent with this fact as well.
Assuming the flat distribution of the M-type PNe to be without any marked concen-
tration toward the galactic centre, let us estimate the total number of such PNe in the Galaxy as ~-, 350.
6. Intermediate Mass PNe (I-Type)
In order to determine the 2(D)-dependence of an I-type PNe, 15 PNe with the most reliable distances were chosen on condition that their mass index be from - 0.3 to + 0.3.
These are PNe NGC1747 , NGC3918 , NGC5189, NGC6369 , NGC6565 ,
N G C 6629, N G C 6803, N G C 6886, N G C 6894, N G C 7008, N G C 7354, IC 2165,
M 1-7, M 1-26, and J 900. Let us consider them in the order they are given in Table IV.
NGC 6369 (PK 2 + 5 ~ I). Its distance was determined by the methods 4 and 5 (Gathier
etaL, 1986; Acker, 1978), the obtained values of d agree well with each other. Like Gathier et al. (1986) we accepted d = 2000 pc, this for S 5 = 2002 mJy and 0 - 28'.'5 giving D = 0.276 pc and logE = - 17.877.
NGC 6565 ( 3 - 4 ~ The distance to this PN was repeatedly measured by the method 1 (Maciel etal., 1986; Gathier etal., 1986; Acker, 1978). We accepted
d = 1300pc, which corresponds to the constructed consolidated dependence of d(EB - v) in the direction of the PN and E B_ v = 0.20. Despite the small value of radio intensity ( S 5 ) = 39 mJy, it is determined with certainty (Gathier et al., 1986; Isaacman, 1984). According to a number of features this PN is classified as anomalous (see Section 7). We accepted 0 = 9"5, D -- 0.062 pc, logZ = - 18.630.
NGC 6629 (PK 9 - 5~ The distance was determined by the methods 4 and 5 (Gathier et al., 1986). Like Sabbadin (1986a) we accepted d = 1500 pc, which cor-
76 P. R. AMNUEL ET AL.
responds to D = 0.112 pc for 0 = 15':5. At S 5 = 292 mJy (Calabretta, 1982) we have logY~ = - 18.181.
N G C 6803 (PK 4 6 - 4 ~ 1). Its distance was determined by the methods 4 and 5
(Gathier etal. , 1986; Acker, 1978). We accepted d = 1800 pc, which for 0 = 5'.'5 and ( $ 5 ) = 101 mJy (Isaacman, 1984; Turner and Terzian, 1984) corresponds to
D = 0.049 pc and logZ = - 17.758. N G C 6886 (PK 60 - 7 ~ Its distance was determined by the methods 4 and 5 (Acker,
1978; Gathier et aL, 1986). The values of 0 = 6"5 and ( S 5) = 99 mJy (Milne, 1979; Pottasch et al., 1984; Isaacman, 1984) were determined with certainty. At d = 2000 pc
we have D = 0.63 pc, logE = - 17.896. N G C 6894 (PK 6 9 - 2 ~ 1). The distance was determined by the methods 3 and 4
(Acker, 1978; Kaler and Lutz, 1985). We accepted d = 1200pc. For 0 = 43" and
( S 5 ) = 72 mJy (Milne, 1979; Daub, 1982) we have D = 0.25 pc, log Y~ = - 19.676. The
PN is classified as anomalous (see Section 7). N G C 7008 (PK 93 + 5~ The distance of the PN was determined by the methods
of individual and mean absorptions (Acker, 1978; Pottasch, 1980). The present determi-
nation of E B_ v = 0.55 corresponds to the distance d = 1 kpc. The values of 0 = 89" and ( $ 5 ) = 2 4 5 m J y (Milne, 1979; Daub, 1982; Phillips, 1984)correspond to
D = 0.436 pc and logZ = - 19.776. N G C 7354 (PK 107+2~ The distance was determined by both variations of
method 3 and by method 5 (Kaler and Lutz, 1985; Gathier et al., 1986); then d = 2 kpc.
Reliable estimates of 0 = 24"5 and ( S 5 ) = 593 mJy (Milne, 1979; Daub, 1982; Kaler
and Lutz, 1985) give D = 0.234 pc and logE = - 18.275. IC 1747 (PK 130 + 1 ~ The distance was determined by the methods 3-5 (Acker,
1978; Daub, 1982; Gathier et al., 1986). Takingd = 2400 pc, 0 = 13", ( S 5 ) = 114 mJy
(Milne, 1979; Kaler and Lutz, 1985; Phillips and Pottasch, 1984; Phillips, 1984) we
obtain D = 0.151 pc and logY. = - 18.419. M 1 - 7 (PK 189+ 7~ The distance was determined by the method of individual
absorption, d - - 2 5 0 0 p c (Sabbadin etal. , 1984). The value of the flux is small,
S 5 = 13 mJy (Milne, 1979). This fact, as well as other parameters of the PN, allow to classify it as anomalous. For 0 = 10" we have D = 0.120 pc and logE = - 19.152.
J9OO(PK 194 + 2 ~ 1). The distance was determined by the methods 3 and 4 (S abbadin,
1986a; Gathier etaL, 1986). We accepted d = 3200pc. For 0 = 10" and ( $ 5 ) = 115mJy (Calabretta, 1982; Isaacman, 1984) we have D---0.152pc, and
log~ = - 18.205. IC 2165 (PK 221 - 12 ~ I). The distance was determined by the methods 4 and 6 and
according to Sabbadin (1986a) d = 2400pc. For 0 = 8" and ( $ 5 ) = 183mJy (Calabretta, 1982; Isaacman, 1984) we have D = 0.096 pc and log~ = - 17.831.
N G C 3918 (PK 294 + 4 ~ i). Its distance was determined by the methods 3 and 4 (Acker, 1978; Gathier etal. , 1986). The difference in determinations is large; we accepted d = 2kpc ; and for 0 = 15" and S 5 = 859mJy (Gathier etaL, 1986) this
corresponds to D = 0.148 pc and logZ = - 17.690. N G C 5189 (PK 3 0 7 - 3 ~ I). The distance was determined by the methods 3 and 4
P L A N E T A R Y N E B U L A E I N T H E G A L A X Y 77
(Acker, 1978; Gathier e ta l . , 1986). We accepted d = 1500 pc which at 0 = 155" cor- responds to D = 1.12pc. The value of S 5 = 413mJy (Gathier e ta l . , 1986) gives logZ = -20.031. This PN is the largest in size among calibrators.
M 1 - 2 6 (PK 358 - 0 ~ i) . This PN is the smallest in size among calibrators. Its distance was determined by the methods 3 and 4. We took d = 1800 pc, which for 0 -- 4':5 and ( S 5 ) = 326 mJy (Calabretta, 1982; Isaacman, 1984; Kwok, 1985) gives D = 0.057 pc and logE = - 17.020.
The E(D) diagram of the I-type calibrators is shown in Figure 14. This figure also shows the dependences of the M- and L-type PNe. O n e can see that the PNe NGC 6565, NGC 6894, and M 1-7 are situated below the dependences of the L-type
I I
- 1 7
t - I
- 1 8
_ 1 9
A \ \
' \ \ \
9
O l l
12 0
\
�9
D \ \
1.5 - I.0 - 0.5 O log D
Fig. 14. The 2(D)-dependence for the I-type PNe. The solid line B is empirical dependence. Lines A and C are corresponding empirical Z(D)-dependences for M- and L-type PNe. The model tracks (long dashed lines) for .~/= 10 - 5 Mo yr - 1 are shown; line E is the CS mass 0.57 Mo , line D is the CS mass 0.64 M o. Filled circles are normal I-type PNe, unfilled ones show anomalous PNe. Ages 103 and 3 x 103 yr are given by short dashed lines. PN designations: 1 - P K 3 5 8 - 0 ~ 2 - P K 2 9 4 + 4 ~ 3 - P K 4 6 - 4 ~ 4 - 2 2 1 - 1 2 ~ 5 - P K 2 + 5 ~ 6 - P K 6 0 - 7 ~ 7 - P K 9 - 5 ~ 8 - P K 1 9 4 + 2 ~ 9 - P K 1 0 7 + 2 ~
1 0 - P K 1 3 0 + 1 ~ 1 1 - P K 3 - 4 ~ 1 2 - P K 1 8 9 + 7 ~ 1 3 - P K 6 9 - 2 ~ 1 4 - P K 9 3 + 5 ~ 15 - PK 3 0 7 - 3~
78 P . R . AMNUEL ET AL,
ones. Like some M-type PNe, these are also classified as anomalous and will be considered in Section 7. The rest of the calibrators are situated between the s
dependences of the M- and L-type PNe. In the region D > 0.05 pc the Z(D)-dependence
of the I-type calibrators is taken by us as
log2; = - 3 logD - 20.77. (8)
In the region D < 0.05 pc the Z(D)-dependence is flatter in accordance with the
situation of calibrators and similar to the s of the L-type PNe. The
theoretical track of PN expansion for the CS masses 0.57 M o and 0 .64M o at ~ / = 10- 5 Mo y r - 1 by the model of Volk and Kwok (1985) is also given here.
As it was done above the mean filling factor ( e ) g 0.7 was determined. Using the Z(D)-dependence, one can obtain that the mass of the I-type PN increases as
logMpn = - 0.1 + logD, (9)
and reaches 0.9 M o at D = 1 pc. As in the case of the M-type PNe, we do not reach
the boundary of the matter ejected at the AGB stage. Thus the Mp,,(D)-dependences of the L-, I-, and M-type PNe are consistent with their mass classification and subdivision
according to our criteria. Evidently, the expansion model at CS mass 0.64 M o (Volk and Kwok, 1985) at 2~/= 10 -5 M o yr-1 is the most suitable for the I-type PNe
(Figure 14). One can check the correspondence of the observed PNe and the PN expansion and
CS evolution models by comparing the corresponding times of evolution as was done above. The estimates are given in Table VII. Here - as mainly for the L-type PNe - the
kinetic ages are close enough to those determined by the s and, at the
same time, these ages are close to the CS ages determined by the L-T diagram. Thus,
both the CS models and those of PN expansion are for the I-type PNe in agreement
with observations. All 94 PNe are classified as a I-type (Table IV). Probably, about 20 are classified as
anomalous. Distances to the I-type PNe obtained by the Z(D)-dependence are given in Table IV. The data on 10 found anomalous PNe are given in Table VIII.
Within 1 kpc from the Sun there are 12 I-type PNe, 4 of them being anomalous. The local surface number density of the I-type PNe (without the anomalous ones) is a o ~ 2.5 k p c - 2. The vlane of the scale-height determined by 15 PNe situated at the
distance of up to 1200 pc is fi = 150 + 20 pc. By use of the values of/? and a 0 as well as the lifetime of the I-type PNe 1.5 x 10 4 yr we shall obtain their local birthrate
Vloca 1 = ( 0 , 8 -}- 0.3) x 10- 12 p c - 3 y r - 1
Unlike the M-type PNe, the I-type ones do not concentrate toward the galactic arms. A small concentration of PNe toward the galactic centre m = 0.11 is observed. Then the total number of the I-type PNe in the Galaxy is ~ 5000, and their total birthrate all
over the Galaxy is Vtota I ~ 0.27 y r - 1
PLANETARY NEBULAE IN THE GALAXY
TABLE VIII
79
PK name d (pc) D (pc) logD Z (pc)
3 - 4~ 1300 0.06 - 1.19 90 11+ 5~ 1200 0.03 - 1.49 110 36 - 57 ~ 1 140 0.59 - 0.23 I10 37 - 34 ~ 1 390 0.05 - 1.31 220 60- 3~ 220 0.39 -0.41 10 63 + 13 ~ 1 460 0.21 - 0.68 100 69- 2 ~ 1 1000 0.22 - 0.67 40
118 - 74 ~ 1 410 0.48 - 0.32 400 130 - 10 ~ 1 740 0.34 - 0.47 130 148 + 57 ~ 1 450 0.49 - 0.31 380 189 + 19 ~ 1 950 0.23 - 0.63 280 189+ 7~ 2800 0.11 -0.94 330 205 + 14 ~ 1 220 0.66 - 0.18 60 217+ 14~ 510 0.76 -0.12 130 272 + 14 ~ 1 610 0.16 - 0.79 130 358 - 7 ~ 1 970 0.22 - 0.66 120
7. Anomalous PNe
By an analysis of the location of different mass class PNe at the E(D) diagram, we found
that some I- and M-type PNe are situated below the Z(D)-dependence of the L-type PNe
(see Figure 15). Is this circumstance only the result of an underest imate of P N distances,
or does it show the real difference of these PNe from other objects of corresponding
mass classes?
Let us first note that the assumption of underestimated distances leads to the opposite
effect: distances to these PNe estimated by corresponding Z(D)-dependences, lead to
abnormally large distances d and diameters D. Thus the average distance from the
galactic plane for the M-type PNe from the group are greater than 500 pc; while for
distances more than 5 kpc, the PN sizes exceed 1 pc. Therefore, the assumption of
distance underest imation is not correct.
If one accepts the correctness of independent estimates of d for this group of PNe,
then the necessity of explaining their irregular location at the E(D) diagram arises.
We have analyzed possible differences of anomalous PNe from corresponding normal
ones by various criteria. No considerable systematic differences were found out, except
for the following three causes:
(1) Anomalous M-type PNe have n e which allow to classify them rather as the I-type
(in the overwhelming majority, according to the criterion 7 the index 0 is observed
instead of 1) - i.e., mainly, the density of matter in these PNe is less than the expected
one according to their mass class.
(2) The chemical composit ion of anomalous PNe, on the average, does not differ
from that of the rest PNe of the same mass class. However, the relative content of
80 P. R. AMNUEL ET AL.
nitrogen in all anomalous PNe is within 8.3 < logN/H + 12 < 8.6. For the same mass
class normal PNe the value logN/H + 12 is uniformly distributed within 7.8 and 8.8. (3) The main characteristic of anomalous PNe is he fact that their ages determined
as by L - T and Z(D) diagrams considerably differ from each other. In all cases the PN age determined by Z(D) diagram and PN evolution model (Volk and Kwok, 1985;
Spergel et aL, 1983) is considerable smaller than that of CS determined by the L - T
diagram. So, for the normal M-type PNe ( t I . - r / t~_z~) = 0.5-0.7, for the normal
I-type PNe ( tL -T / t~_D> =2.5--5, moreover, in the latter case ( t L _ r / t z _ D > increases because of the contribution of PK 34 + 11 ~ 1 where the underestimation of the
CS temperature is possible. As for the anomalous PNe ( t L_ r/t~_D > ~ 40-80; more- over, there is no case in which this ratio would be smaller than 4-5. In 8 cases out of
11 this ratio is greater than 10. The striking difference of the anomalous PN and their CS ages allows us to assume
that the anomalous PNe formed at the relatively later stage of the CS evolution, when
the matter ejected by the star at the AGB stage has time to scatter. Evidently, the
formation of the anomalous PNe is connected with the fact that the CS is subject to
helium outburst (see, e.g., Iben, 1984) as a result of which the CS can for some time ( ~ 103 yr) look like a red giant. As a result of the helium flash, characteristic evolutionary
loop is formed at the L - T diagram. Though some time later the CS return to its general
track, the time necessary to reach the given point at the L - T diagram can considerably
differ from t L _ r calculated by the general track. Besides, unfortunately, the models of
the CS evolution with helium outbursts, which result in loop at the L - T diagram, were
calculated for the stars with masses 0.6 M o, while the anomalous PNe have masses
> 0.64 M o . Thus among the M- and I-type PNe with known distances, 11 ones were chosen
(Table VII) which, according to the numbered features, can be classified as anomalous.
Here there are both the PNe with well-known distances which are not considered as
calibrators because of their mass index (NGC 6720 and N G C 3132) and PNe with unreliable distances. Table IV, for example, gives for the PN 36 - 57 ~ 1 a distance of
100 pc, while in the work of Mendez et al. (1988) the distance estimated by the core
model is ~ 250 pc. Figure 15 shows the Z(D)-dependence of anomalous PNe. In the region log I2 > - 20
the dependence can be approximated by
log12 = - 2 logD - 21.0 ; (10)
and in the region tog Z < - 20.5, by
log12 = - 5 logD - 22.25. (11)
The latter dependence practically coincides with the asymptote of the Z(D)-dependence given in the work of Amnuel et al. (1984). This means that the PN distances determined by Amnuel et al. (1984) for logZ < - 20.5 are correct only for irregular PNe, and should
be reduced for the rest.
PLANETARY NEBULAE IN THE GALAXY 81
- 1 8
W <3
r-I
- 1 9
- 2 0
_ 2"1
B I C I
0 3 4
9
1o II
11
L I I " I
- 1.5 - 1.0 - 0.5 0 log D
Fig. 15. The Z(D)-dependence for anomalous PNe (line A). Lines B and C are dependences for massive and low-mass PNe. PN designations: 1 - P K l l + 5 ~ 2 - P K 3 - 4 ~ 3 - P K 1 8 9 + 7 ~ 4 - P K 2 7 2 + 1 2 ~ 1 7 6 1 7 6 P K 1 8 9 + 1 9 ~ 1 7 6
1 0 - P K 1 4 8 + 5 7 ~ 1 1 - 3 6 - 5 7 ~
The slope of the dependence equal to - 5 shows that, unlike normal PNe, the anomalous ones with diameters D ~> 0.4 pc have the constant mass which does not grow with the increase of D. In order to determine this maximum mass of anomalous PNe according to (5), it is necessary to determine the value of a. Let us find the mean value
of a so as it was done in case of the rest PNe. We establish, first, that e does not depend on D; and, secondly, ( e ) = 0.3. The maximum mass of anomalous PN is then close to 0.08 + 0.02 M o. Thus, evidently, an anomalous PN represents the ejected shell of small mass < 0.1 Me , and is not the result of the compression of the slow wind matter
82 P. R. AMNUEL ET AL.
(or superwind) as in the case of normal PNe. The existing calculations (e.g., Iben, 1984)
show that, in case of a helium outburst, the CS with mass 0.6 M o ejects about 10 - 3 M e . The value of the mass of anomalous PNe is by a factor of magnitude larger.
Probably, the absence of model calculation of CS evolution with masses > 0.6 M o is
the reason of such divergence. We also succeeded in finding out a certain number of anomalous PNe among I- and M-type with unknown distances. The distance to these
PNe was accepted by this, or that the E(D)-dependence of the normal PNe and then
(after the anomaly transpired) was re-estimated by the E(D)-dependence for anomalous
PNe. A PN was considered anomalous if the ratio t L _ r / t z _ D proved large irrespective
of which distance scale was used. The complete list of the established anomalous PNe is given in Table VIII. Out of
16 anomalous PNe, 13 are situated nearer than 1 kpc, this fact showing strong observa-
tional selection for such PNe. The estimated scale height of anomalous PNe fl ~ 150 pc,
once more confirms that they belong to the I- nd M-type. The local surface number density of anomalous PNe a o = 3.8 kpc -2 which for a lifetime t = 2 x 10 4 yr (as the
value of age we took tki,) gives
Vloo~ 1 = (1.3 _ 0.7) x 10- 12 p c - 3 y r - 1
If one compares the obtained frequency with those of normal M- and I-type PNe
formation, it turns out that about a half of CS with masses > 0.6 M o during their
evolution have had at least one helium outburst. The fraction of anomalous PNe is ~ �88 which coincides with independent estimates of the fraction o fPNe CS with the repeating
helium outbursts (Sch0nberner, 1986). However, one should bear in mind that, probably, the greater part of the L-type PNe is also the result of the CS evolution within the loop
at the L - T diagram.
8. Discussion
This work deals with a number of problems concerning the PN formation and evolution.
Let us try to sum up the results and connect them with a number of other problems on
stellar evolution. In Section 3 a number of criteria was analysed which allowed to subdivide the PNe
into three classes: massive (M-type), intermediate mass (I-type), and low mass (L-type). At that, the physical parameters of both parent stars and central stars (CS), and planetary nebulae (PNe) were brought to mutual agreement. It is shown that, as a result of the increase of parent-star mass, a more massive CS and more massive shell (PN) appear at the end of evolution. The existing calculations of the chemical composition of stars do not completely describe the observed picture (Figure 2). Nevertheless, the
data on some chemical elements in a PN (e.g., He, N, Ne) can be used for a rough
estimate of the CS mass (Figure 3). There are CS at the L - T diagram which are situated below the track of evolution
for the mass 0.54 M o. This fact contradicts both the theoretical data on the minimum CS masses and the time of evolution of low-mass CS. One can consider two ways out
PLANETARY NEBULAE IN THE GALAXY 83
of this dilemma: either to calculate the CS evolution with the loss of mass which will
influence the estimate of the CS ages, or assume that the L-type CS undergo helium outbursts, and the whole PN evolution takes place inside the loop on the L - T diagram.
Both hypotheses, in their turn, are contradictory and, therefore, the question on the L-type CS remain open. It is evident that in case of more massive CS (anomalous PNe
- M- and I-type) a helium outburst does take place. However, there are no theoretical models with helium outburst yet for the CS with masses more than 0.6 M o. The model of Iben (1984) for M = 0.6 M o gives the value of the ejected shell lesser by an order of magnitude than is seen from the observations.
Nevertheless, the models of the CS evolution with masses more than 0.57 M o and the PN expansion agree well with the observations. This follows from the cor- respondence of the observed and theoretical Z(D)-dependences, as well as from the
correspondence of evolution times tkin, t z _ z~, and t L _ T . The PNe (excluding anomalous ones) can be considered as the ionized part of the mass ejected by the star at the AGB stage and compressed by the shock-wave which had been formed by the fast wind of the CS. In case of the L- and I-type PNe the ionization front reaches the boundaries
of the compressed mass rather quickly (tki n = tz_D). In case of M-type PNe the ionization front moves slower and in most cases it does not reach the outer boundary of the shell during the PN lifetime.
The comparison of the theoretical and observed Z(D)-dependences not only shows that PN subdivision into mass classes is correct, but it also allows as to estimate the intensity of the mass loss by the star at the AGB stage (see Table IX). The mass-loss rate by the stars generating the M-type PNe is almost by an order of magnitude larger than that of the stars generating those of the L-type. At equal diameters the M-type PNe have their masses larger than that of the I-types. Correspondingly, the mass of the I-type
TABLE IX
L-type I-type M-type Anomalous
Mms/M o 0.8 1.5-2.5 2.5-8 2.5-8 M d M o 0.57 0.57-0.64 0.64 0.57 M A o B ( M o yr -x) 6 x 10 -6 10 -5 4 x 10 -5 -
Mpn/M o 0.6 0.8 1 0.08 <He/H> 0.109 + 0.003 0.120 _+ 0.014 0.149 + 0.010 0.120 +_ 0.007 <N/H> x 104 0.98 x 0.16 2.24 + 0.45 3.51 + 0.45 3.07 + 0.48 < ]Z] > (pc) 220 + 10 150 + 20 120 + 20 150 % (kpc - 2) 6.4 2.5 0.5 3.8 Vloc (10-12 pc - 3 yr -1 ) 2 .3+0.7 0 .8+0.3 1.4+0.6 1.3+0.7 v (yr- 1) 2.3 0.27 0.12 rn (radial distrib.) 0.22 0.11 concentration ?
towards to galactic arms
<~> 1 0.7 0.3 0.3 Ntot~a 3 x 104 5 • 103 350 (3-8) x 103 Nobs 238 64 27 16
84 P .R . AMNUEL ET AL.
PNe is larger than of the L-types. The mass loss time at the AGB stage can be estimated for the L-type PNe as t = 105 yr, and for the I- and M-type one can obtain only the lower
limits of duration of this stage (t > 2 x 10 4 yr). The objects with the most reliable
independent distances were selected among each PN mass class and were used as
calibrators for constructing the Z(D)-dependences. Ten L-type, 6 M-type, and 12 I-type PNe in all were used as calibrators. Meanwhile there are independent distance determi-
nations for 91 PNe (Table IV) with some degree of reliability. The reliability of the
distance scales obtained by Z(D)-dependences can be checked comparing the distances obtained by these dependences with independent ones of all PNe which have cor-
responding estimates. For different classes of PNe we have:
L - t y p e P N e N = 16,
I-type PNe N = 47,
M-type PNe N = 28,
(dind/dz_D) = 1.03 + 0.13,
(dind/dr.-D) = 1.04 + 0.06,
(dind/dx_D) = 1.08 + 0.07.
Thus the accepted Z(D)-dependences give, on the average, the correct values of
distances to the corresponding classes of PNe (within 3-8 ~o). Of course, the errors in
individual distances estimates by the Z(D)-dependence can be much larger, but only in
rare cases they are equal to the true value of the distance. The obtained distance values allow to study the spatial characteristics of PNe:
scale-height, spatial number density, distribution in the Galaxy, birthrate. As it follows
from Table IX, the total birthrate of all class PNe V~oo, ~ = (4.5 + 0 . 6 ) x 10- tz p c - 3 yr-1 . This exceeds approximately twice the present birthrate of white
dwarfs. As was already mentioned by Amnuel et al. (1984) the reason of the divergence can be, for example, the fact that when estimating the white dwarf birthrate only single
stars were used, while the majority of the CS are binaries. As is seen from the comparison
of birthrates of different class PNe with the corresponding ones of white dwarfs (Guseinov et al., 1983), the similar ratio remains constant. This means that the CS mass
distribution is similar to that of white dwarfs. Table IX also shows that the CS mass distribution is wide and asymmetric, shifted toward the M-type CS (the average CS
mass of the M-type PNe is 0.8 Mo). On the average, (Mcs) ~ 0.57 M o (Table IX) which also agrees well with the data
on white dwarfs (Guseinov et al., 1983). Amnuel et al. (1987) compared the deathrates of different mass stars with white dwarf birthrates. Using the similar method one can estimate the initial mass of stars which originate the PNe of different mass classes. At that, the initial mass-function of stars (Miller and Scalo, 1979) was used, and it was assumed that the PNe were formed only if the initial mass of Main-Sequence stars had been not more than 8 M o. It was obtained that the evolution of stars with initial mass 2.5-8 M o leads to the formation of the M-type PNe; while the I-type PNe are formed as a result of the evolution of stars with initial masses 1.5-2.5 M o, and the L-types after the evolution of stars with masses 0.8-1.5 M o. Both the PN scale-height and the galactic distribution of different mass-class PNe correspond well to these values of mass (see Table IX). The obtained data also allow to conclude that there is not any con-
PLANETARY NEBULAE IN THE GALAXY 85
siderably way of the death of stars with masses less than 8 M o at which the stage of the PN would not appear. This conclusion agrees with the results obtained by Auer and
Wolf (1965), Wolf (1974), Guseinov and Novruzova (1974), and others, it is based on a vast observational material. However, the number of the present-day existing material is also insufficied to answer the question: which is, in reality, the minimum mass of single white dwarfs and central stars?
9. Conclusions
(1) Ten criteria according to which one can determine the PN mass class (type) are analysed. Four of these are connected with the mass class of the parent star, three are connected with the mass class of very PN, one with the CS mass class and another two are connected with the CS and PN masses combined. The PNe are divided into three mass classes.
(2) There is a direct dependence between the masses of the parent star, CS, and PN. (3) In order to determine distances to the PNe, the Z(D)-dependences at 5 GHz are
considered. One-hundred thirty-one PNe are classified as low mass (L-type), 27 PNe as massive (M-type), 94 PNe as intermediate mass (I-type), 27 and 3 PNe as L/I and I/M-types accordingly. The distances for the L/I-type PNe are obtained by the Y{D)- dependence for the L-type PNe, the distances for the I/M-type PNe are obtained by the 2(D)-dependence for the M-type PNe. We did not successed in classifying 62 PNe (marked with '?').
For constructing the Z(D)-dependences, 10 L-type, 6 M-type, and 12 I-type PNe were used. The distance scales obtained give a mean accuracy of distance determinations of 3 -8%.
(4) The values of scale-height and local surface number densities of different mass- class PNe have been obtained. The data are given in Table IX. The local PN birthrates
o f different mass classes are estimated. The total PN birthrate is Vlooa 1 = 4.5 x 1 0 - 1 2 p c - 3 y r -1.
(5) The L-type PNe are rather strongly concentrated toward the galactic centre. The concentration of the I-types is considerably less pronounced; while those of the M-type concentrate toward the galactic arms. The total number of all mass-class PNe in the Galaxy can reach ~ 4 x 104. Annually 2 -4 PNe form in the Galaxy.
(6) It follows from the analysis and comparison of theoretical models with observa- tions that the evolution of the M-type PNe is best described by the model in which the CS has its mass 0.8M@ and the outflow of the mass at the AGB stage is 3;I ,,~ 4 • 10-5 Mo yr-1. The evolution of the I- and L-type PNe is correspondingly described by the CS with masses 0.64 M@ and 0.57 M o with mass losses at the AGB stage ~ 1 0 - 5 and ~ 6 x 1 0 - 6 M o y r - 1 .
(7) The filling factor ~ is practically independent of the PN diameter and for different mass class PNe it is close to 1, 0.7, and 0.3, respectively, for the L-, I-, and M-type PNe. A continuous increase of the PN-ionized mass up to D ~ 1 pc is observed at that.
(8) The I- and M-type PNe with anomalously small values of E make up a special
86 P. R. AMNUEL ET AL.
class. Anomalous PN ages calculated by their location at the 2(D)-dependence are considerably smaller than the ages of their CS calculated by the location at the L - T diagram. Evidently, anomalous PNe are the result of a secondary ejection of the CS mass at the stage of helium outburst after the initial PN scattered in space. The mass of ejected shell does not exceed 0.08 M o. We succeeded in identifying 16 anomalous PNe and specifying their parameters.
In the theory of CS and PN evolution, an interesting and important task is presented by the anomalous PN. This is connected with the possibility of the ejection of a rather massive shell in ~ 10 4 yr after the formation of the CS. Furthermore, an increase of the observational material will allow to classify the PN by their masses in detail, to identify whether a PN belongs to this or that mass type of the object.
References
Acker, A.: 1978, Astron. Astrophys. Suppl. Ser. 33, 367. Acker, A.: 1980, Astron. Astrophys. 89, 33. Acker, A.: 1983, Etoiles binaires diagramme H.R.C.r. journdes 5dme reun. Strasbourg, 20 janvier, 1983,
Strashourg, p. 103. Acker, A., Marcout, J., and Schohn, C.: 1983, Catalogue of the Central Stars of True and Possible Planetary
Nebulae. Adam, J. and K6ppen, J.: 1985, Astron. Astrophys. 142, 461. Adam, S., Seaton, M. J., Howarth, I. D., Auri6re, M., and Walsh, J. R.: 1984, Monthly Notices Roy. Astron.
Soc. 207, 471. Aller, L. H.: 1982, Astrophys. Space ScL 83, 225. Aller, U H.: 1983, Astrophys. J. Suppl. Ser, 51, 211. Aller, L. H. and Keyes, C. D.: 1987, Astrophys. or. SuppL Set. 65, 405. Aller, L. H., Keyes, C. D., and Czyzak, S. J.: 1981, Astrophys. J. 250, 596. Aller, L. H., Keyes, C. D., and Czyzak, S. J.: 1985, Astrophys. J. 296, 492. Aller, L. H., Keyes, C. D., Maran, S. P., Gull, T. R., Michalitsianos, A. G., and Stecher, T. P.: 1987,Astrophys.
Y. 32O, 159. Altschuler, D. R., Schneider, S. E., Gionavardi, C., and Silverglate, P. R.: 1986, Astrophys. J. 305, L85. Amnuel, P. R., Guseinov, O. H., Novruzova, H. I., and Rustamov, Yu. S.: 1984, Astrophys. Space Sci. 107,
19. Amnuel, P. R., Guseinov, O. H., Novruzova, H. I., and Rustamov, Yu. S.: 1985, Astrophys, Space Sci. 113,
59. Amnuel, P. R., Guseinov, O. H., Novruzova, H. I., and Rustamov, Yu. S.: 1987, Astrofizika 27, 53 (in
Russian). Auer, L. and Wolff, N.: 1965, Astrophys. J. 142, 182. Barker, T.: 1983, Astrophys. J. 267, 630. Barker, T.: 1984, Astrophys. J. 284, 589. Barker, T.: 1985, preprint. Barker, T. and Cudworth, K. M.: 1984, Astrophys. J. 278, 610. Beck, S. C., Lacy, J. H., Townes, C. H., Aller, L. H., Geballe, T. R., and Baas, F.: 1981, Astrophys. J. 249,
592. Becker, S. A. and Iben, I.: 1980, Astrophys. J. 237, 111. Bianchi, L. and Grewing, M.: 1985, Calibration of Fundamental Stellar Quantities, Proc. IIIth Syrup., Como,
May 24-29, 1984, D. Reidel Pub1. Co., Dordrecht, Holland, p. 603. Bianchi, L., Carrato, S., and Grewing, M.: 1986, Astron. Astrophys. 169, 227. Cahn, J. H.: 1984, Astrophys. J. 279, 304. Cahn, J. H. and Kaler, J. B.: 1971,Astrophys. & Suppl. Ser. 22, 319. Calabretta, M. R.: 1982, Monthly Notices Roy. Astron. Soc. 199, I41. Cohen, M., Fitzgerald, M. P., Kunkel, W., Lasker, B. M., and Osmer, P. S.: 1978, Astrophys. J. 221, 151.
PLANETARY NEBULAE IN THE GALAXY 87
Cudworth, K. M.: 1974, Astron. J. 79, 1384. Daub, C. T.: 1982, Astrophys. J. 260, 612. Dufour, R. J.: 1984, Astrophys. J. 287, 341. Dinerstein, H. L.: 1980, Astrophys. J. 237, 486. Faundez-Abans, M. and Maciel, W. J.: 1986, Astron. Astrophys. 158, 228. Feibelman, W. A.: 1983, PubL Astron. Soc. Pacific 95, 886. Feibelman, W. A.: 1984, Astrophys. J. 287, 353. Flower, D. R.: 1982, Monthly Notices Roy. Astron. Soc. 199, 15. French, H. B.: 1983, Astrophys. J. 273, 214. Gathier, R.: 1987, Astron. Astrophys. SuppL Ser. 71,245. Gathier, E., Pottasch, S. R., and Goss, W. M.: 1983, Astron. Astrophys. 127, 320. Gathier, R., Pottasch, S. R., and Pel, J. W.: 1986a, Astron. Astrophys. 157, 171. Gathier, R., Pottasch, S. R., and Goss, W. M.: 1986b, Astron. Astrophys. 157, 191. Goharje, A. and Adams, S.: 1984, Monthly Notices Roy. Astron. Soc. 210, 683. Golovaty, W., Pronik, V. I., and Jacik, O. S.: 1979, Izvestiya Crimean Astrophys. Obs. 59, 167 (in Russian). Greig, W. E.: 1971, Astron. Astrophys. 10, 161. Greig, W. E.: 1972, Astron. Astrophys. 18, 70. Guseinov, O. H. and Novruzova, H. I.: 1974, Astrofizika 10, 273 (in Russian). Guseinov, O. H., Novruzova, H. I., and Rustamov, Yu. S.: 1983, Astrophys. Space Sci. 97, 305. Harpaz, A. and Kovetz, A.: 1987, Astrophys. ,7. 323, 154. Heap, S. R.: 1987, Nature 326, 571. Hua, C. T. and Grundseth, B.: 1985, Astron. J. 90, 2055. Iben, I.: 1984, Astrophys. J. 277, 333. Isaacman, R.: 1984a, Astron. Astrophys. 130, 151. Isaacman, R." 1984b, Monthly Notices Roy. Astron. Soc. 208, 399. Ishida, K. and Weinberger, R.: 1987, Astron. Astrophys. 178, 227. Johnson, H. M.: 1981, Astrophys. J. 250, 590. Kaler, J. B.: 1981, Astrophys. J. 250, 231. Kaler, J. B.: 1983a, Astrophys. J. 264, 594. Kaler, J. B.: 1983b, Astrophys. J. 271, 188. Kaler, J. B.: 1984, preprint IAP 84-23. Kaler, J. B. and Feibelman, W. A.: 1985, Astrophys. J. 297, 724. Kaler, J. B. and Hartkopf, W. I.: 1981, Astrophys. J. 249, 602. Kaler, J. B. and Lutz, J. R.: 1985, Publ. Astron. Soc. Pacific 97, 700. Kaler, J. B., Mo, Jing-Er, and Pottasch, S. R.: 1985, Astrophys. J. 288, 305. Koester, D. and Weidemann, V.: 1980, Astron. Astrophys. 81, 145. Kwitter, K. B., Yacoby, G. H., and Lawrie, D. C.: 1983, Publ. Astron. Soc. Pacific 95, 732. Kwok, S.: 1985, Astron. J. 90, 49. Landaberry, S. J. C., Pachego, J. A. F., Viadona, L., and Bazzanella, B.: 1986, Rev. Mexicana Astron. Astrof
12, 191. Lutz, J. H.: 1984, Stellar Nucleosynthesis, Proc. 3rd Workshop, Adv. Sch. Astron., Ettore, Majorana Cent.
Sci. Cult., Erice, May 11-21, 1983, D. Reidel Pnbl. Co., Dordrecht, Holland, p. 15. Maciel, W. J.: 1981, Astron. Astrophys. Suppl. Ser. 44, 123. Maciel, W. J.: 1984, Astron. Astrophys. Suppl. Set. 55, 253. Maciel, W. J. and Pottasch, S. R.: 1980, Astron. Astrophys. 88, 1. Maciel, W. J., Faundez-Abans, M., and Oliveira, M. de: 1986, Rev. Mexicana Astron. Astrof 12, 233. Mendez, R. M., Kudritzki, R. P., and Simon, K. P.: 1985, Astron. Astrophys. 142, 289. Mendez, R. M., Kudritzki, R. P., Herrero, A., Husfeld, D., and Groth, H. D.: 1988, Astron. Astrophys. 190,
113. Miller, I. and Scalo, I.: 1979, Astrophys. J. Suppl. Ser. 41, 513. Milne, D. K.: 1979, Astron. Astrophys. SuppL Ser. 36, 227. Milne, D. K. and Aller, L. H.: 1975, Astron. Astrophys. 38, 183. Paeheco, J. A. de F. and Veliz, J. G.: 1987, Monthly Notices Roy. Astron. Soc. 227, 773. Pacheco, J. A. de F., Codina, S. J., and Vidana, L.: 1986, Monthly Notices Roy. Astron. Soc. 220, 107. Paczyflski, B.: 1971, Acta Astron. 21,417. Peimbert, M.: 1978, 'Planetary Nebulae: Observations and Theory', in Y. Terzian (ed.), IA U Syrup. 76, 2 t5.
88 P.R. AMNUEL ET AL.
Phillips, J. P.: 1984, Astron. Astrophys. 137, 92. Phillips, J. P. and Pottasch, S. R.: 1984, Astron. Astrophys. 130, 91. Pottasch, S. R.: 1980, Astron. Astrophys. 89, 336. Pottasch, S. R.: 1984, Planetary Nebulae, D. Reidel Publ. Co., Dordrecht, Holland. Pottasch, S. R., Band, B., Beintema, D., Emerson, J., Habing, H. J., Harris, S., Houck, J., Jennings, R., and
Marsden, P.: 1984, Astron. Astrophys. 138, 10. Pottasch, S. R., Dennefeld, M., and Jinger, M.: 1986, Astron. Astrophys. 155, 397. Pwa, T. H., Mo, J. E., and Pottasch, S. R.: 1984, Astron. Astrophys. 139, L1. Reay, N. K., Pottasch, S. R., Atherton, P. D., and Taylor, K.: 1984, Astron. Astrophys. 137, 113. Renzini, A. and Voli, M.: 1978, Astron. Astrophys. 94, 175. Rodrigues, L. F., Garcia-Barreto, J. A., Canto, J., Moreno, M. A., Torres-Peimbert, S., Costero, R.,
Serrano, A., Moran, J. M., and Garay, G.: 1985, Monthly Notices Roy. Astron. Soc. 215, 353. Rosado, M.: 1986, Rev. Mexicana Astron. Astrof 13, 49. Sabbadin, F.: 1984, Monthly Notices Roy. Astron. Soc. 210, 341. Sabbadin, F.: 1986a, Astron. Astrophys. 160, 31. Sabbadin, F.: 1986b, Astron. Astrophys. Suppl. Set. 64, 579. Sabbadin, F. and Hamzaoglu, E.: 1981, Monthly Notices Roy. Astron. Soc. 197, 363. Sabbadin, F. and MineUo, S.: 1978, Astron. Astrophys. Suppl. Set. 33, 223. Sabbadin, F , Bianchini, A., and Hamzaoglu, E.: 1984a, Astron. Astrophys. 136, 200. Sabbadin, F., Falomo, R., and Ortolani, S.& 1984b, Astron. Astrophys. 137, 177. Sabbadin, F., Bianchini, A., Ortolani, S., and StrafeUa, F.: 1985,Monthly Notices Roy. Astron. Soc. 217, 539. Sahu, K. C. and Desai, J. N.: 1986, Astron. Astrophys. 161,357. Schmidt-Voigt, M. and K6ppen, J.: 1987a, Astron. Astrophys. 174, 211. Schmidt-Voigt, M. and KOppen, J.: 1987b, Astron. Astrophys. 174, 233. Schneider, S. E., Silverglate, P. R., Altschuler, D. R., and Gionavardi, C.: 1987, Astrophys. 3. 314, 572. Schneider, S. E., Terzian, Y., Purgathofer, A., and Perinotto, M.: 1983, Astrophys. J. SuppL Set. 52, 399. Sch6nberner, D.: 1979, Astron. Astrophys. 79, 108. Sch6nberner, D.: 1981, Astron. Astrophys. 103, 119. Sch6nberner, D.: 1984, 'Observational Thesis of Stellar Evolution Theory', p. 209. Sch6nberner, D.: 1986, Astron. Astrophys. 169, 189. Shaw, R. A. and Kaler, J. B.: 1985, Astrophys. J. 295, 537. Shibata, N. and Tamura, S.: 1985, Publ. Astron. Soc. Japan 37, 325. Shklovsky, I. S.: 1956, Astron. Zh. 33, 315 (in Russian). Spergel, D., Giualiani, J., and Knapp, C.: 1983, Astrophys. J. 275, 330. Stankievich, K. S. and Scharova, O. I.: 1983, Astron. Zh. 60, 931 (in Russian). Storey, J. W. V.: 1984, Monthly Notices Roy. Astron. Soc. 206, 521. Surdej, A., Surdej, J., and Swings, J. P.: 1982, Astron. Astrophys. 105, 242. Taylor, A. R., Pottasch, S. R., and Zhang, C. Y.: 1987, Astron. Astrophys. 171, 178. Torr~s-Peimbert, S.: 1985, Rev. Mexicana de Fisica 31, No. 2, 199. Turner, K. C. and Terzian, Y.: 1984, Astron. J. 89, 501. Tylenda, R.: 1983, Astron. Astrophys. 126, 299. Volk, K. M. and Kwok, S.: 1985, Astron. Astrophys. 153, 79. Weidemann, V.: 1987, Astron. Astrophys. 188, 74. Weinberger, R. and Zeiner, R.: 1988, Astron. Astrophys. 191, 297. Woolf, N.: 1974, 'Late Stages of Stellar Evolution', in R. Taylor (ed.), IAU Symp. 66, 43. Wood, P. R. and Faulkner, G. J.: 1986, Astrophys. J. 307, 659. Zuckerman, B. and Aller, L. H.: 1986, Astrophys. J. 301, 772. Zuckerman, B. and Gatley, I.: 1988, Astrophys. a r. 324, 501.
![[OIII] Observations of Six Planetary Nebulae](https://img.pdfslide.net/doc/110x75/56814585550346895db2662c/oiii-observations-of-six-planetary-nebulae.jpg)
