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The Physics of Supernovae

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1 The Physics of Supernovae
Inma Domínguez Universidad de Granada Santiago de Chile, octubre de 2007

2 Chemical Evolution Cosmology Trigger Star formation Neutrinos
SN 1987A Chemical Evolution Cosmology Trigger Star formation Neutrinos BH, NS, GRBs Reionization of the Universe etc etc

3 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 life SN1054 was as luminous as the moon for some days RARE: About 1 per century in our Galaxy Last recorded seen by naked-eye : (Lupus), 1054 (Chinese), 1572 (Brahe), 1604(Kepler) BRIEF: Luminosity falls by a factor of 100 in 4 months

4 Standard Candles Fainter  Further Distance Modulus
Luminosity Distance

5 SNe Classification Based on spectra and light curve morphology SNe
I b (strong He) I c (weak He) SNe II P Type II II L No H H Type I I a (strong Si) Core collapse of massive stars Thermonuclear explosion

6 Basic SN type spectra

7 Light Curves Type II SN Type Ia SN Dramatic differences
Similar luminosity Similar spectral evolution Good distance indicators Cosmological parameters Type II SN Dramatic differences II-P (plateau) II-L (rapid declination) Cosmology

8 SNe RATE Galaxy Ia Ib/c II E-S0 0.04 < 0.01 S0a-Sb 0.065 0.026 0.12
SN rate per unit Mass (10-10 M yr (Ho/75)2 Galaxy Ia Ib/c II E-S0 0.04 < 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

9 SN Ia in E-S0 Old populations
SN Ib/c & SNII Absent in E-S0 Young populations Short lived progenitors Massive  SN Ia in E-S0 Old populations Long lived progenitors Low mass  in Binary Systems SN Ia rate  in Spirals Galaxies-with SFR Part of SN Ia comes from a younger population Cappellaro et al 2003, Mannucci et al. 2005, Sullivan et al. 2006

10 Stellar Evolution  AGB SN Ia SN II Ib/c ~ 1 Myr ~ 1-10 Myr
M<0.8 M¤ 0.8<M/M¤<8 8<M/M¤<11 11<M/M¤<100 M>100 M¤ 30 Myr<t< 15 Gyr 0.5<Mf /M¤< CO WD t>1/Ho t~10-30 Myr Mf = M¤ ONeMg WD ~ 1-10 Myr Mf = M¤ Fe collapse NS/BH ~ 1 Myr may or may not explode AGB SN Ia SN II Ib/c

11 Classification of SNe ~ 4000 SNe (nowadays > 300 /yr)

12 Solar System Abundances
1H 4He 16O 12C O 20Ne 56Fe N=50 N=82 N=126 The most abundant isotopes: 1H 4He 16O 12C 20Ne (-elements)


14 50 yrs !!

15 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 t1/2  106 yr Tc has been synthesized inside the star

16 Origin of the Elements: Nuclear Statistical Equilibrium (NSE) ?
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 !!

17 Binding Energy per nucleon
BE/c2=[Zmp + (A-Z)mn - m(A,Z)] BE/A 56Fe smallest mass per nucleon to 56Fe exothermic reactions © Rolfs & Rodney 1988

18 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

19 Most abundant nuclei Nuclear Physics Physical Conditions
Where & When ?? Anders & Grevesse 1989

20 Solar System Abundances
© Cameron 1982 Abundances peak at the “magic numbers”,Z: 2, 8, 20, 28, 56, 82 He, O, Ca, Fe, Ba, Pb

21 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).

22 Solar System Abundances
SNII BBN SNII SNII ? AGB SNIa BBN AGB Anders & Grevesse 1989 Cameron 1982

23 Some definitions… “Metallicity”: [Fe/H] = log (Fe/H) – log (Fe/H)
“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 ?)

24 Stellar Evolution & Nucleosynthesis
The activation of a nuclear burning phase The stellar life-time DEPEND on Mass AGB Planetary Nebulae White Dwarfs CCSNe Neutron  (Pulsars) Black Holes (if) Binary Systems Novae SNe Ia AIC: Neutron  (Pulsars) “Less” in Z…


26 Low mass stars M < 8 M AGB/Planetary Nebulae return
C, N, s-elements etc to the ISM

27 (accreting mass from a companion)
Exploding CO WDs (accreting mass from a companion) Type Ia Supernovae (SN Ia or Thermonuclear SNe) SN Ia produce ~2/3 of the observed Fe in the Universe

28 Massive  25 M Chieffi, Limongi, Straniero 1998

29 Massive stars M ≥ 8-10 M likely r-p-elements into the ISM
Core Collapse Supernovae eject O, Mg, Ti and likely r-p-elements into the ISM

30 Origin of the elements 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

31 The Origin of the Elements up to Zn
L* M < 8M neut. Irra CR Cosmic Rays ApJS 1995 s shell x Explosive rich freeze out

32 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)

33 Some definitions Yields Mass Loss !! in M Production Factor

34 Yields + Evolution-Time  Chemical Evolution
SN Ia + SNII 20Ne 24Mg 28Si 32S 36Ar 40Ca Fe SN II -elements time Chemical Evolution

35 -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)

36 Initial mass function (IMF)
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

1 Dimension Lagrangian Hydrostatic + Chemical Evolution

Convection (a problem !!)  Time-dependent convection  Mixing-Nuclear burning coupled Micro-physics EOS Opacity Nuclear Cross Sections (Strong & Weak) Screening factors Neutrinos

39 NUCLEAR NETWORK High number of Isotopes
64Zn 66Zn 67Zn 68Zn 65Zn 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 51Ti 46Ti 45Ti 44Ti 51Mn 52Mn 53Mn 44Sc 45Sc 46Sc 47Sc 48Sc 49Sc 41Sc 42Sc 43Sc 42Ca 43Ca 44Ca 45Ca 46Ca 47Ca 48Ca 40Ca 41Ca 38K 39K 40K 41K 42K 48Cr 49Cr 37K 49Ca 38Ar 39Ar 40Ar 41Ar 35Ar 36Ar 37Ar 38Cl 35Cl 36Cl 37Cl 33Cl 34Cl 58Cu 59Cu 60Cu 61Cu 62Cu 35S 36S 37S 33S 34S 32S 31S 33P 34P 32P 31P 30P 27Mg 27Si 33Si 32Si 31Si 30Si 28Si 29Si 27Al 26Mg 24Mg 25Mg 23Na 22Ne 20Ne 21Ne 19F 18O 16O 17O 16N 14N 15N 14C 12C 13C 19O 17F 18F 13N 15O 20F 21Na 22Na 23Ne 24Na 25Al 26Al 28Al 47V 48V 46V 52Fe 53Fe 54Co 55Co 56Co 57Co 29P 56Ni 57Ni 63Zn 60Zn 61Zn 62Zn 65Ni 66Cu 52V 55Cr 61Fe 67Cu 23Mg 45V 57Mn 50Sc 62Co 57Cu 11B 10B 10Be 8Be 9Be 7Be 7Li 6Li 4He 3He 3H 2H 1H n High number of Isotopes High Number of Nuclear Reactions p, n and  captures e± captures ± Decay (p,g) (a,n) (a,g) (a,p) (p,n) (p,a) (n,g) (n,p) (n,a) (g,n) (g,p) (g,a) b+,e- b-,e+ Extensive Nuclear Networks  Automatic Adaptive Network

40 THE FRANEC CODE MAIN PROGRAM (Finite difference Henyey Method)
Strong reactions Weak reactions Neutrinos Initial stellar parameter (mass, chemical composition) Opacities Equation of State First model at the beginning of the Pre-MS Atmosphere Adaptive re-zoning Definition of Convective borders MAIN PROGRAM (Finite difference Henyey Method) Mixing Mass loss Physical evolution Chemical evolution THE FRANEC CODE New temporal step Output

41 AGB Thermonuclear SNe Core Collapse SNe

42 Evolution of Low & Intermediate Mass Stars

43 Schematic structure of an AGB star
(not to scale)

44 Evolutionary track toward the WD
0.6 CO 0.55 He 0.2 CO 0.1 He 0.5 He M=1 M t =10 Gyr Remnant: CO WD 0.6 M WD MS RGB HB AGB PN Prada Moroni & Straniero 2002

45 A WD in a binary system toward a thermonuclear explosion
2 WDs WD + 

46 “Universally” accepted model for Ia:
Thermonuclear Explosion of a CO WD M~MChandrasekhar ~ 1.4 M Light Curve 56Ni  56Co 56 Fe L time Lmax  MNi Supernova Cosmology Project

47 WD is degenerate Pressure for relativistic electrons:
e- Degenerate Pressure (EOS) Fowler  Pauli Exclusion Principle Pressure for relativistic electrons: P independent of T The Chandrasekhar limit Thermonuclear Explosion nuc < hyd

48 Thermonuclear Explosions
RG WD SD Compressional heating MCh DD ignition Propagation of the burning front WD C-deflagration C or He detonation C-delayed detonation Detonation vburnvsound Deflagration vburn< vsound Delayed detonation Deflagration Detonation

49 Still Key Problems to control SNIa !!
Progenitors ? CO WD + companion SD vs DD… both ?? Accretion ?? CSM: 2002ic Hamuy et al. Nature 2003 2005gj Aldering et al 2006X Patat et al. Science NORMAL SNIa Explosion Mechanism ? begin subsonic 1D parametrization 3D still … fighting !! (Barcelona, Chicago, MPI, NRL)

50 Massive  Core Collapse
At the end... Layered Structure Dense Iron Core  107 g·cm-3 T  1010 K MCore  1.4M RSi-Core  4000 km RFe-Core  800 km

51 Massive  Core Collapse
Fusing Main Fusion Products Time H He 6 million years He C, O years C Ne, O years Ne O 9 Months O S, Si, Ar 4 Months Si Fe, Cr day End result ? A star whose core looks like an onion

52 Collapse and Explosion
M=25M Chieffi & Limongi He Shell H Centrale C conv. Shell He Centrale H Shell O conv. Shell 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 Si burning(Cent.+Sehll) 4He 16O 1H 28Si “Fe” 20Ne 12C Collapse and Explosion

53 Core-Collapse Mechanism
Once the star has finished its fuel the core cools because of two reasons: Iron dissociation  fusion of light nuclei  the star continues emitting energy Degenerate e- gas  p + e-(2.25 MeV) n + e (neutronization)  e escape and remove energy Not enough energy to mantain the thermal equilibrium + not enough pressure to mantain the hidrostatic equilibrium, then the contraction turns into a free fall collapse and as 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)

54 Core-Collapse Mechanism
Making Stars Explode 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 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

55 Core Collapse SNe: LCs simulated by a piston of initial velocity v0,
located near the edge of the Fe core Explosion Mechanism Still Uncertain II-P 1. Rise: thermal energy (envelope is fully ionized) 2. Plateau: recombination of H Lenght  MH 3. Radioactive Tail: 56Co decay L  M56Ni 56Ni  56Co 56 Fe II-L No Plateau Small H-envelope

56 Numerical Methods STELLAR EVOLUTION Low-mass  Massive 
FRANEC (Chieffi, Domínguez, Imbriani, Limongi, Piersanti, Straniero) 1D Hydrostatic Code Extended Nuclear Network (700 isotopes) Physics and Chemestry coupled Time dependent mixing Low-mass  PMS  AGB  WD  Accretion  Explosive C-ignition  TPs Massive  PMS  Fe-core

57 Numerical Methods EXPLOSION & LIGHT CURVES
1D Radiation-Hydrodynamic Code (PPM) (Höflich, Khokhlov ) Extended Nuclear Network (postprocess) Radiation transport via moments eq. Expansion opacities (scatt., bf, bb) Explosion mechanism: detonation deflagration piston  CCSNe  SNIa LCs  Ray transport  Monte Carlo Frequency dependent transport eq. (1000 ) + Eddington fac. Mean opacities

58 Observations LCs Spectra (evolution) Observed Relations Lmax  LC
Lmax  B-V Lmax VCa Lmax VNi 2001el SNIa Krisciunas et al. 2003 1999em IIP Hamuy et al. 2001 1999ee SNIa Hamuy et al. 2002

59 Information from the spectra
Hoflich et al. 2000 -4 days + 15 days C-burning Star of Si burning MgII 1.05m SN1999by SNIa Sub-L CaII 1.15m Duration of these phases  lower limit to the mass

60 SN Remnants Crab Nebula SN 1054 Visible X-ray IR Radio

61 Type Ia SN remnants: shocked ejecta
Ca Fe Si Tycho SN 1572 Fe Ar XMM-Newton Interaction with the Ambient Medium AM~ g/cm3 PDDT X-ray emission spectra DDT  T Xi ionization Ca Identify Explosion Mechanism  DDT Fe PDDT Sub-Ch Badenes et al. 2003

62 Cas A Si Fe Chandra Age ~ 300 yr SN1680 Good spatial resolution
X and Optical data  CCSNe He-rich envelope Hwang et al. 2004 SiXIII/MgXI Asymmetrically expanding  Explosion ?? Vink et al. 2004

63 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.

64 Bibliography Galaxies, Cambridge University Press.
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,

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