(Informal) workshop - Ferrara April 2004

SNe

Astrophysical (natural) Explosive Devices

Thermonuclear SNe

Gravitational collapse

C-deflagration

He-detonation

C-delayed detonation

Induced Core collapse (nuclear runaway fails)

Pair instability, core collapse & O explosion (core collapse fails)

SNe Classification

Core collapse of massive stars

Thermonuclear explosion

I b (strong He)

I c (weak He)

SNe

II p

Type II

II L

No H

H

Type I

I a (strong Si)

based on spectra and light curves morphologies

Type Ia light curve Riess et al. , 1997

Brighter Slower Decline

Dimmer Faster Decline

standard candles visible

up to z ~ 1

Supernova Cosmology Project

High-z Team (Brian Schmidt & co)

The Universe is Accelerating

0.25 mag fainter than for an EMPTY Universe

(Saul Perlmutter & co.)

DL

z Fainter Further

Moq 21

Type IIp light curve:

potentialstandard

candles up to z ~ 5

(with NGST)

log

log

P

5/3

4/3

M1

M2

Non-degenerate

Non-relativistic

relativisticCollapse or ig

nition

The virial theorem: stellar core evolution

5.1

3

1

0

2

0

M

Md

M

R

r

Mq

VPR

GMq

r

dMMG

rr

Rrr

g

3

2

3

442 MRMP

457.15.0

83.5 2

Che

eCh

MYif

YM

Stellar evolution

M<0.8 M

0.8<M/M<8

8<M/M<11

11<M/M<100

M>100 M

GyrMyr 0.5<Mf /M<1.1 CO WD

Myr Mf

=1.2-1.3 M ONeMg WD

1-10 Myr Mf =1.2-2.5 M Fe (Ye0.45) collapse NS or BH1Myr O (pair jnstability) (Ye=0.5) may or may not explode

4He

16O

12C

5 M

Z=0.02 Y=0.28

He-burning: the competition between He-burning: the competition between

33 ->-> 1212C and C and 1212C+C+ ->->1616O+O+

Ex (keV) J

10957

10367

9847 9580

8872

7117 6917

6130

6049

0

0-

4+

2+

1-

2-

1-

2+

3-

0+

0+

1212C+C+44HeHe

2418

2685 3195

ECM (keV)

Gamow peack energies Gamow peack energies

-45

-245

1616O O level schemelevel scheme

Q = 7.162 MeV

Low Adop. high

Kunz et al 2001

5.25 7.58 10.2

Buchmann 1996

3.04 7.04 13.04

NACRE 5.44 9.11 12.8

CF88 4.74

CF85 11.3

Na<,v> (10-15 cm3mol-1s-

1) for T9=0.2

Not an error bar

Carbon left in the core Carbon left in the core 0.8M0.8M < M < 25M< M < 25M (from Imbriani et al. (from Imbriani et al.

2001).2001).

High rate – empty circle Low rate - Black circle

1 Hp overshoot – triangle Breathing pulses - square

CO WD

ONeMgWD

Core Collapse

Bright Homogeneous No evolutionary effects

Supernovae Ia

Light Curve

L

time

56Ni 56Co 56 Fe

Thermonuclear Explosionof a CO WDM~MChandrasekhar

L MNi

~ 1.4 M

H accreting WDsSingle Degenerate system: WD+RG RG

MS

Merging scenario:Double Degenerate system: CO+CO

a) GWR: ang. momentum loss

b) secondary tidal disruption

c) accretion 10-5 Myr-1

Roche lobe overflow

White Dwarf interior: C and O profiles

12C()16

O

High rate

Low rate

12C(,n)16O and the final mass of 56Ni

M(56Ni)=10%

15.3 d 18.0 dRise time

-19.30-19.21MV

LOWHIGHRate

18± 0.4 dHIGH Rate C/O

Observed:

from Dominguez, Hoflich, Straniero 2002

Massive stars

from Limongi, Chieffi & Straniero 2001

e-,e+

e-

Pressure contributionsDegenerate electrons

Thermal contributio

n

At the onset of the core collapse

18.145.0 Che MY

• e-+p n+e (10 MeV)

• 56Fe+ 13+4n (124 MeV)

COLLAPSE, BOUNCE & STALL

+0.2 ms

-0.5 ms +2.0 ms

1012 g/cm3

3x1014 g/cm3

1051 erg lost each 0.1 Mo

subsonic | supersonic

hard core (1014 g/cm3)

Ye and 12C()16O

18.145.0 Che MY

Low rate (solid)

High rate (dotted)

from Imbriani et al. 2001

M-R relation:high rate = shorter C burning =

more compact

progenitor

Observable consequences: SN yields

1) I ntermediate-light elements, Ne, Na, Mg, and Al (which are produced in the C convective shell), scale directly with the C abundance lef t by the He burning because they depend directly on the amount of available f uel. 2) All the elements whose yields are produced by any of the f our explosive burnings (complete explosive Si burning, incomplete explosive Si burning, explosive O burning, and explosive Ne burning) scale inversely with the C abundance lef t by the He burning because the mass-radius relation in the deep interior of a star steepens as the C abundance reduces. 3) A low C abundance (about 0.2 by mass f raction), or an high rate, is required to obtain yields with a scaled solar distribution. 5) A low C abundance leads to smaller iron cores, thus f avoring the explosion.