SN 1987A
Chemical Evolution Cosmology Trigger Star formation Neutrinos BH, NS, GRBs Reionization of the Universe etc etc
Supernovae are one of the most energetic explosive events in Nature
• BRIGHT A SN in 10 sec releases 100 times the energy that the sun
releases in all its lifeSN1054 was as luminous as the moon for some days
• RARE: About 1 per century in our GalaxyLast recorded seen by naked-eye :1006 (Lupus),
1054 (Chinese), 1572 (Brahe), 1604(Kepler)
• BRIEF: Luminosity falls by a factor of 100 in 4 months
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 curve morphology
Light Curves
Type Ia SN•Similar luminosity
•Similar spectral evolution Good distance indicatorsCosmological parameters
Type II SN•Dramatic differences
•II-P (plateau)•II-L (rapid declination)
• Cosmology
SNe RATE
Galaxy
Ia Ib/c II
E-S0 0.04 < 0.01 < 0.01
S0a-Sb 0.065 0.026 0.12
S0c-Sd 0.17 0.067 0.74
Irr 0.77 0.21 1.7
Mannucci et al. 2005
SN rate per unit Mass (10-10 M 10-2 yr (Ho/75)2
SN Ia in E-S0 Old populations
Long lived progenitors Low mass in Binary Systems
SN Ib/c & SNII Absent in E-S0 Young populations Short lived progenitors Massive
SN Ia rate in Spirals Galaxies-with SFRPart of SN Ia comes from a younger population Cappellaro et al 2003, Mannucci et al. 2005, Sullivan et al. 2006
Stellar EvolutionM<0.8 M
0.8<M/M<8
8<M/M<11
11<M/M<100
M>100 M
MyrGyr
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 collapse NS/BH
~ 1Myr
may or may not explode
SN II Ib/c
AGBSN Ia
-12
-11
-10
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
0 20 40 60 80 100 120 140 160 180 200 220
Atomic Weight
Lo
g M
as
s F
rac
tio
n
The most abundant isotopes: 1H 4He 16O 12C 20Ne (-elements)
O16O
4He
1H
12C20Ne 56Fe
N=50 N=82 N=126
Solar System Abundances
Origin of the Elements: Inside the Stars
Observational Evidences:
Pop II Less heavy elements by a factor of 100 Our Galaxy has synthesized 99 % of the heavy elements during ¡ts evolution
Merril (1952) discovered Tc in All Tc isotopes decay 1/2 106 yr
Tc has been synthesized inside the star
Klein, Beskow & Treffenberg (1947)
Studied the abundances at NSE
in function of T and
rate nuc. re. = inverse rate
This mechanism could not reproduce the observed abundances
But NOT bad for the Fe peak !!
Origin of the Elements:
Nuclear Statistical Equilibrium (NSE) ?
),(),( TnfZAN n
Binding Energy per nucleonBE/c2=[Zmp + (A-Z)mn - m(A,Z)]
© Rolfs & Rodney 1988
BE/A
56Fe smallest mass per nucleonto 56Feexothermic reactions
The interpretation of the abundances
The Peaks in the abundances of 4He, 12C, 16O, 20Ne and other elements capture nuclear reactions inside the stars
Fe-peak elements
56Fe is the isotope with higher binding energy 56Fe is the last product of exothermic nuclear fusion reactions, NSE
Elements heavier than Fe
High Coulomb barrier for charge reactions Neutron captures
Solar System Abundances
Abundances peak at the “magic numbers”,Z: 2, 8, 20, 28, 56, 82 He, O, Ca, Fe, Ba, Pb
© Cameron 1982
The familiar picture H burning (the most effective, with an average of 7MeV per nucleon of generated energy): produced 4He, 3He, and gives (generally secondary) contributions to intermediate nuclei up to Si.
He burning (the second-most effective): produces 12C, 16O, some 20Ne, plus secondary chains starting from 14N or 13C and leading to neutron generation.
Fusion of intermediate nuclei - 12C, 16O, 20Ne, 28Si nuclei below and up to the Fe-peak.
Nuclear statistical equilibrium (NSE) processes, crossing the peak at 56Fe - 56Ni.
Explosive nucleosynthesis, starting from NSE and reorganizing abundances up to 65Cu, occur in CCSNe and in SN Ia.
Neutron captures (slow and rapid – s and r - processes).
Some definitions…
• “Metals”: elements heavier than helium, Z
• “Metallicity”: [Fe/H] = log (Fe/H) – log (Fe/H)
• “Abundance ratio”: [X/Y]= log (X/Y) – log (X/Y)* Abundance scale by number: 12 log N(H)* Mass fractions: X= Hydrogen (X~0.71) Y= Helium 4 (Y~0.27) X+Y+Z= 1 Z= Metals (Z~0.02)
Population I objects (stars): Z ~ Z
Population II : Z << Z
Population III : Z ~ 0 (not detected yet ?)
Stellar Evolution & Nucleosynthesis
Mass AGB Planetary Nebulae White Dwarfs
(if) Binary Systems
Novae SNe Ia AIC: Neutron (Pulsars)
Neutron (Pulsars) Black Holes
CCSNe
The activation of a nuclear burning phase The stellar life-time DEPEND on
“Less” in Z…
R
MTc
Exploding CO WDs (accreting mass from a companion)
SN Ia produce~2/3 of the observed Fe in the Universe
Type Ia Supernovae (SN Ia or Thermonuclear SNe)
Massive stars M ≥ 8-10 M
Core Collapse Supernovae eject O, Mg, Ti and likely r-p-elements into the ISM
-12-11-10
-9-8-7-6-5-4-3-2-1012
0 20 40 60 80 100 120 140 160 180 200
Atomic Weight
Lo
g M
as
s F
rac
tio
n
BB CR neut.Novae IMS SNIISNIa s-r
BB = Big Bang; CR = Cosmic Rays; neut. = ν induced reactions in SNII;IMS = Intermediate Mass Stars; SNII = Core collapse supernovae;SNIa = Thermonuclear supernovae; s-r = slow-rapid neutron captures
Origin of the elements
The Origin of the Elements up to Zn
ApJS 1995L* M < 8M
neut. IrraCR Cosmic Rays
s shellx Explosive rich freeze out
Yields Low and Intermediate Mass Stars 4He C N s-process (A > 90) elements Lattanzio et al., Meynet & Maeder, Marigo et al., Siess et al. Straniero et al. (TERAMO), Siess et al., Van den Hoeck & Groenewegen Ventura et al.
Type Ia Supernovae Fe and Fe-peak Nomoto et al., Iwamoto et al. Höflich et al., Thielemann et al.
Massive stars -elements (O, Ne, Mg, Si, S, Ca), some Fe-peak, s-process elements (A < 90) and r-process elements.
Woosley & Weaver / Limongi & Chieffi (ORFEO)
Some definitions
Yields
Production Factor
Meje
i
Meje
i
i
dmX
dmX
PF0
Meje
itii dmXXYield )( 0
Mass Loss !!
in M
Yields + Evolution-Time Chemical Evolution
time
SN II
SN Ia + SNII
FeMgFeMgFeMg /log/log/
Chemical Evolution
-elements
Fe
20Ne24Mg28Si32S36Ar40Ca
-enhancements appear naturally due to the different life-times between SNII and SNIa… but at what level? and when?
Modification of the IMF: more massive stars produce more “alphas”Modification of the SFR: more “alphas” produced before SNIa appear
© McWilliam (1997)
Ingredients of GCE
Initial conditions Big Bang abundances Prompt initial enrichment
Initial mass function (IMF) Relative birthrates of stars with different masses
Star formation rate (SFR) Constant, burst, interruptions etc
Stellar yields vs. stellar mass and metallicity SNII, SNIa, AGB, Novae, etc
Galactic gas inflow/outflow Late infall of primordial gas etc Supernova-driven galactic winds etc Stellar & gas dynamics
),,(4
),,(),,(),,(
),,(4
1
4
2
2
4
i
igraviinuc
i
YTPPr
GmT
m
T
YTPYTPYTPm
L
YTPrm
r
r
Gm
m
P
STELLAR EVOLUTION EQUATIONS
1 Dimension Lagrangian Hydrostatic
Ni
YYYvNlkjc
YYvNkjcYjct
Y
lklkj
jlkjAi
kkj
jkjAij
jjii
,........,1
),,(
),()(
,,,,
22
,,
+ Chemical Evolution
Pdl
Tdl
n
n
STELLAR EVOLUTION EQUATIONS
Convection (a problem !!)
tmix Time-dependent convection
Mixing-Nuclear burning coupled nucmix
Micro-physics
EOS Opacity Nuclear Cross Sections (Strong & Weak) Screening factors Neutrinos
Extensive Nuclear Networks Automatic Adaptive Network
64Zn 66Zn 67Zn 68Zn65Zn
63Cu 65Cu
58Ni 59Ni 60Ni 61Ni 62Ni 63Ni 64Ni
54Fe 55Fe 56Fe 57Fe 58Fe 59Fe 60Fe
64Cu
58Co 59Co 60Co 61Co
54Mn 55Mn 56Mn
50Cr 51Cr 52Cr 53Cr 54Cr
49V 50V 51V
47Ti 48Ti 49Ti 50Ti 51Ti46Ti45Ti44Ti
51Mn 52Mn 53Mn
44Sc 45Sc 46Sc 47Sc 48Sc 49Sc41Sc 42Sc 43Sc
42Ca 43Ca 44Ca 45Ca 46Ca 47Ca 48Ca40Ca 41Ca
38K 39K 40K 41K 42K
48Cr 49Cr
37K
49Ca
38Ar 39Ar 40Ar 41Ar35Ar 36Ar 37Ar
38Cl35Cl 36Cl 37Cl33Cl 34Cl
58Cu 59Cu 60Cu 61Cu 62Cu
35S 36S 37S33S 34S32S31S
33P 34P32P31P30P
27Mg
27Si 33Si32Si31Si30Si28Si 29Si
27Al
26Mg24Mg 25Mg
23Na
22Ne20Ne 21Ne
19F
18O16O 17O
16N14N 15N
14C12C 13C
19O
17F 18F
13N
15O
20F
21Na 22Na
23Ne
24Na
25Al 26Al 28Al
47V 48V46V
52Fe 53Fe
54Co 55Co 56Co 57Co
29P
56Ni 57Ni
63Zn60Zn 61Zn 62Zn
65Ni
66Cu
52V
55Cr
61Fe
67Cu
22Na
26Al
44Ti
60Fe
60Co
44Sc
23Mg
45V
57Mn
50Sc
62Co
57Cu
11B10B
10Be8Be 9Be7Be
7Li6Li
4He3He
3H2H1H
n(p,)
(,n) (,)
(,p)(p,n)
(p,)
(n,)
(n,p)
(n,)
(n)
(p)
()
NUCLEAR NETWORK
High number of IsotopesHigh Number of Nuclear Reactions
p, n and captures e± captures ± Decay
THE FRANECCODE
MAIN PROGRAM(Finite difference Henyey Method)
Strong reactionsWeak reactions
Neutrinos
OpacitiesEquation of State
Initial stellar parameter (mass, chemical composition)
First model at the beginning of the Pre-MS
Definition ofConvective
borders
Mixing
Adaptive re-zoning
Mass loss
Atmosphere
Physicalevolution
Chemical evolution
Newtemporal stepOutput
C-O core
He intershell
H-rich convective envelope
He-burning shell
H-burning shell
Dredge-up
Flash-driven intershell convection
Schematic structure of an AGB star (not to scale)
Schematic structure of an AGB star (not to scale)
Evolutionary track toward the WD
0.6 CO
0.55 He 0.2 CO
0.1 He
0.5 He
0.6 CO
WD
MS
RGBHB
AGB
PNM=1 M
t =10 Gyr
Remnant: CO WD 0.6 M
Prada Moroni & Straniero 2002
Light Curve
L
time
56Ni 56Co 56 Fe
Thermonuclear Explosionof a CO WDM~MChandrasekhar
Lmax MNi
~ 1.4 M
“Universally” accepted model for Ia:
Supernova Cosmology Project
WD is degenerate
Pressure for relativistic electrons:
3
4
3
12
4
3
HR mA
ZcP
1926 Fowler Pauli Exclusion Principle
P independent of T
Thermonuclear Explosion
e- Degenerate Pressure (EOS)
The Chandrasekhar limit
MM
eCh
22
456.1
nuc < hyd
Thermonuclear Explosions
C-deflagration
C or He detonation
C-delayed detonation
RGWD
WD WD
SD
DD
Detonation vburnvsound
Deflagration vburn< vsoundDelayed detonationDeflagration Detonation
Propagation of the burning front
MCh
Compressionalheating
WD
ignition
Still Key Problems to control SNIa !!
Progenitors ? CO WD + companion SD vs DD… both ?? Accretion ??
1D parametrization3D still … fighting !! (Barcelona, Chicago, MPI, NRL)
begin subsonic Explosion Mechanism ?
CSM: 2002ic Hamuy et al. Nature 2003 2005gj Aldering et al. 2005 2006X Patat et al. Science 2007 NORMAL SNIa
Massive Core
Collapse
At the end...Layered StructureDense Iron Core
107 g·cm-3
T 1010 KMCore 1.4M
RSi-Core 4000 kmRFe-Core 800 km
Massive Core
Collapse
Fusing Main Fusion Products TimeH He 6 million years He C, O 700000 yearsC Ne, O 1000 yearsNe O 9 MonthsO S, Si, Ar 4 MonthsSi Fe, Cr 1 day
End result ? A star whose core looks like an onion
Burning Site Main Products
Si Burning 54Fe, 56Fe, 55Fe, 58Ni, 53Mn
O Conv. Shell 28Si, 32S, 36Ar, 40Ca, 34S, 38Ar
C Conv. Shell 20Ne, 23Na, 24Mg,25Mg, 27Al + s-process
He Centrale 16O, 12C + s-process
He Shell 16O, 12C
H Centrale+Shell
14N, 13C, 17O S
i b
urn
ing
(Ce
nt.
+S
eh
ll)
O c
on
v.
Sh
ell
C c
on
v.
Sh
ell
He
Ce
ntr
ale
He
Sh
ell
H S
he
ll
H C
en
tra
le
16O28Si
20Ne
12C
4He1H
“Fe”
M=25M
Chieffi & Limongi
Collapse and Explosion
Core-Collapse Mechanism
Once the star has finished its fuel the core cools because
of two reasons:
c) Contraction turns into a free-fall collapse,vast amount of neutrinos are produced
In less than 1 second the inner core radius goes from 4000 km to 10 km
(matter from the rest of the core is falling inward)
a) Iron dissociation fusion of light nuclei the star continues emitting energy
b) Degenerate e- gas p + e-(2.25 MeV) n + e
(neutronization) e escape and remove energy
Core-Collapse MechanismMaking Stars Explode
PROBLEM: Turning the implosion into an explosion !!!There are several models explaining the explosion,
but until now simulations do not succeed in obtaining an explosion
Because the neutrinos free path is small the falling matter becames very hot
and expands outwards.
Finally, the star explodes and ejects the star’s outer
layers into space.
All that remains of is a very dense object: neutron star or black hole
Core Collapse SNe: LCs
L M56Ni 56Ni 56Co 56 Fe
II-P1. Rise: thermal energy (envelope is fully ionized)2. Plateau: recombination of H Lenght MH
3. Radioactive Tail: 56Co decay
II-L No Plateau Small H-envelope
simulated by a piston of initial velocity v0, located near the edge of the Fe core
Explosion Mechanism Still Uncertain
Numerical Methods STELLAR EVOLUTION
FRANEC (Chieffi, Domínguez, Imbriani, Limongi, Piersanti, Straniero)
1D Hydrostatic Code Extended Nuclear Network (700 isotopes) Physics and Chemestry coupled Time dependent mixing
PMS AGB WD Accretion Explosive C-ignition
TPs
PMS Fe-core
Low-mass
Massive
Numerical Methods EXPLOSION & LIGHT CURVES
1D Radiation-Hydrodynamic Code (PPM)(Höflich, Khokhlov )
Ray transport Monte Carlo Frequency dependent transport eq. (1000 )
Extended Nuclear Network (postprocess) Radiation transport via moments eq. Expansion opacities (scatt., bf, bb) Explosion mechanism: detonation deflagration piston CCSNe
LCs
Eddington fac.Mean opacities
+
SNIa
1999ee SNIaHamuy et al. 2002
1999em IIPHamuy et al. 2001
2001el SNIaKrisciunas et al. 2003
Observations
Lmax LCLmax B-VLmax VCa
Lmax VNi
LCsSpectra (evolution)Observed Relations
Information from the spectra
-4 days + 15 daysC-burning Star of Si burning
Duration of these phases lower limit to the mass
SN1999byMgII1.05m
CaII1.15m
Hoflich et al. 2000
SNIaSub-L
Type Ia SN remnants:shocked ejecta
Tycho SN 1572
X-ray emission spectra
Interaction with the Ambient Medium AM~ 10-24 g/cm3
T Xi ionization
XMM-Newton
DDTPDDT
PDDT Sub-ChIdentify Explosion Mechanism DDT
Fe
Fe
Ca
Ca
SFe
O
SiAr
Badenes et al. 2003
Cas A
Asymmetrically expanding Explosion ??
Age ~ 300 yr SN1680
Good spatial resolution
X and Optical data CCSNe He-rich envelope
SiXIII/MgXI
Vink et al. 2004
Hwang et al. 2004
Chandra Si
Fe
Bibliography
BÖHM-VITENSE 1993, Introduction to Stellar Astrophysiscs, University of Chicago Press. CLAYTON 1992, Principles of Stellar Evolution and Nucleosynthesis, University of Chicago Press. HANSEN & KAWALER 1994, Stellar Interiors: Physical Principles, Structure and Evolution, Springer-Verlag
KIPPENHAHN 1990, Principles of Stellar Structure and Evolution, Springer-Verlag.
OSTLIE & CARROLL 1996, An Introduction to Modern Stellar Astrophysics, Addison Wesley.
Bibliography
PAGEL 1997, Nucleosynthesis and Chemical Evolution of Galaxies, Cambridge University Press.
BUSSO, GALLINO, WASSERBURG 1999, Nucleosynthesis in AGB stars, Ann. Rev. A. &A., 36, 369.
WALLERSTEIN et al. 1998, Synthesis of the elements in stars forty years of progress, Reviews of Modern Physics, Volume 69,