The Physics of Supernovae

Inma Domínguez

Universidad de Granada

Santiago de Chile, octubre de 2007

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

Standard Candles

Fainter Further Distance Modulus

Luminosity Distance

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

Basic SN type spectra

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

Classification of SNe

~ 4000 SNe (nowadays > 300 /yr)

-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

50 yrs !!

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

Most abundant

nuclei

Anders & Grevesse 1989

Nuclear Physics

Physical Conditions

Where & When ??

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).

Solar System Abundances

Anders & Grevesse 1989Cameron 1982

SNIIBBN

SNII

SNIa

AGB

SNII ?AGB

BBN

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

Low mass stars M < 8 M

AGB/Planetary Nebulae return C, N, s-elements etc to the ISM

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)

25 M

Massive

Chieffi, Limongi, Straniero 1998

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

AGB

Thermonuclear SNe

Core Collapse SNe

Evolution of Low & Intermediate Mass Stars

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

A WD in a binary systemtoward a thermonuclear

explosion2 WDs

WD +

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

Visible

X-ray

IR

Radio

SN Remnants

Crab NebulaSN 1054

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,