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Solar flare observations with INTEGRAL/SPI. (M. Gros, J. Kiener, V. Tatischeff et al.). Nuclear g -rays. e -. p, a. Hard X-rays. Neutrons. CORONA. TRACE & RHESSI, 28-Oct-2003. 2.22 MeV g -ray line. CHROMOSPHERE. n. PHOTOSPHERE. H. 12 C*. 12 C. p. - PowerPoint PPT Presentation
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Solar flare observations Solar flare observations with INTEGRAL/SPIwith INTEGRAL/SPI
IEEC, Barcelona, September 23, 2004
(M. Gros, J. Kiener, V. Tatischeff et al.)
TRACE & RHESSI, 28-Oct-2003
CHROMOSPHERE
PHOTOSPHERE
CORONA
e-
Hard X-raysp, ...
Nuclear -rays
Neutrons
2.22 MeV -ray line
H
12Cp
h
12C*
Nuclear de-excitation lines:
n
The INTEGRAL satelliteThe INTEGRAL satellite
IEEC, Barcelona, September 23, 2004
Launched (Proton) on 17 Oct 2002
Ge detector matrix
Masks
BGO shield
ISGRI (CdTe)
PICSIT (CsI)
SPI IBIS
E Range (MeV)
~0.02–10
ISGRI: ~0.02–1 PICsIT: ~0.16–
10
(FWHM)
2.5° 12’
E (FWHM)
3 keV @ 1.7 MeV
9 keV @ 100 keV 80 keV @ 1
MeV
Scientific objectives: AGN, -ray bursts, compact objects, novae, SNe, interstellar -ray emissions...
Interest of SPI for solar flare Interest of SPI for solar flare physicsphysics
IEEC, Barcelona, September 23, 2004
Compact array of 19 hexagonal Ge detectors (Stot=500 cm2): good efficiency
at high energy (compared to RHESSI) using "multiple events"
Anti-Coincidence veto System (ACS) of 91 BGO scintillator crystals: Spro~6000–9000 cm2
32 °
Ge detector matrix
Masks
BGO shield
ISGRI
PICSIT
BGO shield
SPI observations of the 2003 Oct 28 solar flare SPI observations of the 2003 Oct 28 solar flare (X17.2)(X17.2)
IEEC, Barcelona, September 23, 2004
During INTEGRAL observation of IC443 (rev 127; PI: A. Bykov)
Simulated response function for the satellite configuration during the flare: in progress (Weidenspointner et al.) All results are preliminary
Measured spectra and time Measured spectra and time historyhistory
With all types of Ge events (including multiples 2-5)
mostly instrumental
pair prod.
IEEC, Barcelona, September 23, 2004
4.44 and 6.13 MeV line characteristics4.44 and 6.13 MeV line characteristics
Rest Energy(keV)
% Redshift % FWHM
4438.030.632 0.097
1.67 0.24
0.79 2.06
6128.630.59 0.12 1.95 0.38
0.58 1.99
+ 0.95- 0.65
+ 0.24- 0.29
RHESSI results are for the 23 July, 2002 X4.8 flare (73° helio. angle) - Smith et al. 2003
+ 1.11- 0.83
+ 0.23- 0.22
Compton
IEEC, Barcelona, September 23, 2004
Best fit results:12C only : /p = 0.00 = 20°16O only : /p = 0.09 = 34°12C +16O : /p = 0.03 = 29°
common best fit16O best fit
common best fit12C best fit
68.3 % C.L.90 % C.L.95.4 % C.L.
4.44 and 6.13 MeV line shape 4.44 and 6.13 MeV line shape calculationscalculations
IEEC, Barcelona, September 23, 2004
Detailed model based on laboratory data
Sensitive to the angular distribution of the accelerated particles and the /p ratio
The 6.92 and 7.12 MeV lines of The 6.92 and 7.12 MeV lines of 1616O*O*
Fit with a fixed line shape: same relative redshift and FWHM as for the 6.13 MeV line
The two 16O* lines at ~7 MeV are resolved for the first time
From a simplified model of solar -ray absorption:
Line Energy (MeV)
Relative fluences
2.2 10.7 1.7
4.4 0.92 0.14
6.1 1.00 0.17
6.9 0.33 0.13
7.1 0.20 0.12
IEEC, Barcelona, September 23, 2004
Gamma-ray line ratiosGamma-ray line ratios
Fast ion composition: Solar Energetic Particles (SEP) from impulsive flares
Fast ion energy spectrum: dN/dE E-S
Nuclear de-excitation lines (thick target production model) compared to 2.22 MeV line production (Hua et al. 2002) S
Smax for /p=0.1
Smin for /p=0.1
?
IEEC, Barcelona, September 23, 2004
With a stochastic acceleration With a stochastic acceleration spectrumspectrum
The source spectrum should be a modified Bessel function rather
than a power law (e.g. Forman et al.
1986).
no improvement for C/O
: acceleration efficiency T: escape time
from the acceleration region
?
IEEC, Barcelona, September 23, 2004
With SMM and OSSE dataWith SMM and OSSE data 9 SMM flares with strong (and complete) -ray line emission (SM95)
OSSE: 1991 June 4 flare (Murphy et al. 1997)
RHESSI results not yet taken into account
?
S determination for the 1989 Nov 15 flare
Correction for heliocentric angle
IEEC, Barcelona, September 23, 2004
The The 1212C/C/1616O line ratio O line ratio problemproblem
IEEC, Barcelona, September 23, 2004
Calculated 4.44)/6.13) overestimates by a factor of ~1.5 the average line ratio obtained from SMM, OSSE and SPI data.
Origin of the problem: - the interaction model ? - the cross sections ? - the abundances of 12C and 16O in the ambient medium (coronal, from gradual event SEP) ?
comparison with the 2 other significant lines detected with SMM and OSSE: at 1.37 (24Mg*) and 1.63 MeV (20Ne*)
from Ramaty et al.
Cross sections Cross sections (1)(1)
Mainly from KMR02 (ApJ Suppl), the figures.
4.44 MeV line S=3 S=4.5
a: 12C(p,p’)12C* 47.4%
43.1%
b: 14N(p,x)12C* () 1.6% 0.2%
c: 16O(p,x)12C* 35.7% 9.5%
d: 12C(,’)12C* 8.7% 39.3%
e: 14N(,x)12C* () 0.4% 0.3%
f: 16O(,x)12C* 6.3% 7.5%
A(b,c)D: cross section measured by the -ray method (10–20% uncertainties)
(): Cross sections overestimated in KMR02 ; calculated with EMPIRE-II (nuclear statistical model)
(with /p=0.1)
IEEC, Barcelona, September 23, 2004
Cross sections Cross sections (2)(2)
6.13 MeV line 6.129 MeV (16O*) + 6.175 MeV (15O*),
but not the 6.322 MeV line (15N*), see Mandzhavidze et al. (1999).
S=3 S=4.5
a: 16O(p,p’)16O* 67.0% 42.7%
b: 20Ne(p,x)16O* 6.0% 1.6%
c: 16O(p,x)15O* 11.0% 0.5%
d: 16O(,’)16O* 15.2% 54.4%
e: 20Ne(,x)16O* () 0.6% 0.8%
f: 16O(,x)15O* <0.1% <0.1%
(): Cross section not considered in KMR02, calculated with EMPIRE-II
IEEC, Barcelona, September 23, 2004
Cross sections Cross sections (3)(3)
7 MeV lines 6.92 MeV + 7.12 MeV (16O*)
S=3 S=4.5
a: 16O(p,p’)16O*6.92 78.0% 40.0%
c: 16O(,’)16O*6.92 22.0% 60.0%
b: 16O(p,p’)16O*7.12 87.1% 52.3%
d: 16O(,’)16O*7.12 12.9% 47.7%
• Minor contributions (neglected) from 20Ne spallation (EMPIRE-II)
IEEC, Barcelona, September 23, 2004
Cross sections Cross sections (4)(4)
1.63 MeV line 1.634 MeV (20Ne*) + 1.636 MeV (23Na*) + 1.635 MeV (14N*)
S=3 S=4.5
a: 20Ne(p,p’)20Ne* 55.1%
62.1%
b: 24Mg(p,x)20Ne*,23Na* 20.5% 4.1%
c: 28Si(p,x)20Ne* 5.3% 0.5%
d: 20Ne(,’)20Ne* 7.0% 27.1%
e: 24Mg(,x)20Ne*,23Na* 2.5% 1.3%
a’: 14N(p,p’)14N* 4.1% 2.9%
b’: 16O(p,x)14N* 4.9% 0.3%
c’: 14N(,’)14N* 0.6% 1.8%
IEEC, Barcelona, September 23, 2004
Cross sections Cross sections (5)(5)
1.37 MeV line 1.369 MeV (24Mg*) + 1.370 MeV (55Fe*) + 1.367 MeV (59Ni*)
S=3 S=4.5
a: 24,25,26Mg(p,x)24Mg* 85.8%
74.5%
b: 28Si(p,x)24Mg* 7.2% 0.9%
c: 56Fe(p,x)55Fe* 1.1% 0.1%
d: 24Mg(,’)24Mg* 5.3% 22.2%
e: 56Fe(,n)59Ni* 0.6% 2.3%IEEC, Barcelona, September 23, 2004
theory=20% (due to )
added in quadrature to data for the 2 probabilities
Goodness-of-fits:
Ambient medium coronal
but ASEP(C) is too high
/p=0.1 is favored. Then Ne/O0.15 and Mg/O0.20The Dec 16, 1988
Flare. Not included in the probability calculations. Ambient photosph. ?
IEEC, Barcelona, September 23, 2004
With the 1.63 With the 1.63 and 1.37 MeV and 1.37 MeV
lineslines
The Dec 16, 1988 Flare. Not included in the probability calculations. Ambient photosph. ?
same results, but on average the probabilities are slightly lower as S
With With S from S from 2.222.22//6.136.13 only only
IEEC, Barcelona, September 23, 2004
Good consistency of the 3 probability distributions
From maximum likelywood: (C/O) = 0.28 0.03 (1)0.28 0.08 (2)
The C abondance in the interaction The C abondance in the interaction regionregion
IEEC, Barcelona, September 23, 2004
With /p=0.
1(C/O)SEP=0.460.01
(Reames 1999)
(C/O)pho=0.500.08
(Lodders 2003)
A new photospheric C abundance A new photospheric C abundance ??
• Anders & Grevesse (1989)
• Grevesse & Sauval (1998)
• Holvecker (2001)
• Lodders (2003)
• Asplund et al. (2004), A&A for O, in prep. for C
IEEC, Barcelona, September 23, 2004
(C/O)chr~0.3 but (C/O)pho=0.5 ?
Apho(C) and Apho(O) are uncertain:
recent substantial revisions (NLTE, 3D models)
A reduced Asol(C) would better fit the
C abondance gradient in the Galactic disk (see Hou et al. 2000, fig. 6)
for /p=0.1
speculative
The photospheric The photospheric 33He He abundance*abundance*
The time evolution of the 2.22 MeV line emission is sensitive to Apho(3He):
{3He(n,p)3H}1.6·104{1H(n,)2H}
NRC = 1 / {n(3He)·NRC·vn}
= RC (H/3He) 6.25·10-5
IEEC, Barcelona, September 23, 2004
Neutron-production time history prompt -ray line emission (good quality data with SPI)
*Not measured by atomic spectroscopy*Not measured by atomic spectroscopy
Neutrons 2.22 MeV
H
n
p e-
e n 3He
3H
n
p
Chromosphere Photosphere
No PAS
Strong PAS
The magnetic loop model The magnetic loop model
IEEC, Barcelona, September 23, 2004
(Hua, Lingenfelter, Murphy, Ramaty...)
CHROMOSPHERE
PHOTOSPHERE
CORONA
isotropic accelerated- particle release
MHD turbulence pitch-angle scattering
B (pressure)
constant B
magnetic mirroring (sin2 B)
“loss cone"
No PAS (mean free path ): “fan beam“ of interacting particles (i.e. parallel to the solar surface)
Strong PAS: loss cone continuously repopulated “downward beam“
Hua et al. (2002)
Calculated 2.22 MeV lightcurvesCalculated 2.22 MeV lightcurves
IEEC, Barcelona, September 23, 2004
Monte-Carlo code (Hua et al. 1987, 2002) to simulate: (i) the propagation and interaction of the accelerated
particles (ii) the neutron production and propagation(iii) the 2.22 MeV line production and
absorption
For instantaneous release of the accelerated particles, the 2.22 MeV lightcurves fall faster with increasing PAS (decreasing ) and increasing 3He/H (see Murphy et al. 2003)
The two free parameters are strongly correlated from 4.44 and 6.13 MeV line shapes more accurate 3He/H Solar neutron measurements (monitors + CORONAS/SONG) could help...
The photospheric The photospheric 33He abundance: He abundance: resultsresults
fan beam
downward beam
IEEC, Barcelona, September 23, 2004
From -ray spectroscopy of the 2003 Oct 28 solar flare with SPI:
- energy spectrum of the accelerated ions (-ray line fluences)
- accelerated /p ratio (-ray line shapes and fluences)
- amount of PAS in magnetic loop/angular distribution of the interacting particles (-ray line shapes and 2.22 MeV
lightcurve)
acceleration and transport processes
- ambient C abundance (-ray line fluences)
- ambient 3He abundance (2.22 MeV lightcurve)
solar composition and atmospheric response
Much more to do:
- timing analyses using the ACS (and radio data)
- analyses of the 2003 Nov 4 flare (near the solar limb !)
...
SummarSummaryy
IEEC, Barcelona, September 23, 2004