Current Status ofMassive Star Evolution
Takashi Yoshida
Hideyuki Umeda, Koh Takahashi, Shinpei Okita
Department of Astronomy, University of Tokyo

Quarks to Universe in Computational Science (QUCS2012)
13th December, 2012, Nara Prefectural New Public Hall

Current Status
A03: Astrophysics Project
Massive star model (TY & Umeda 2011, Umeda, TY & Takahashi 2012)
Wide ranges of main-sequence (MS) mass MMS and metallicity Z
Effect of stellar rotation
Current status
Very massive stars (MMS ~> 100 M ) as a progenitorfor super-luminous supernova (SLSN)
Pulsational pair-instability (PPI) supernova
Aspherical core-collapse SNe from very massive stars
Progenitor for electron-capture supernova(Poster A03-P27: Takahashi, TY & Umeda)
Evolution of rotating massive star (test calculation)
MMS=15 M , Z=0.02, vrot=200 km/s star model
Takashi Yoshida QUCS2012, Nara, December 13, 2012

Massive Stars as Progenitors for Supernovae

1, 2003

DEATH OF MASSIVE STARS

291

H-envelope(Heger & Woosley 2003)
He/CO core

ONe/Electron-capture
supernovae

Core-collapse
supernovae

Pulsational
pair-instability
supernovae
Pair-instability
supernovae

SLSN?
Massive Stars

Progenitors for supernovae
Progenitor structure is important for supernova explosions.

g. 2.—Supernovae types of nonrotating massive single stars as a function of initial metallicity and initial mass. The lines have the same meaning as in
1. Green horizontal hatching indicates the domain where Type IIp supernovae occur. At the high-mass end of the regime they may be weak andvationally faint because of fallback of 56Ni. These weak SN Type IIp should preferentially occur at low metallicity. At the upper right-hand edge of theype II regime, close to the green line of loss of the hydrogen envelope, Type IIL/b supernovae that have a hydrogen envelope of d2 M! are made ( purplehatching). In the upper right-hand quarter of the figure, above both the lines of hydrogen envelope loss and direct black hole formation, Type Ib/cnovae occur; in the lower part of their regime (middle of the right half of the figure) they may be weak and observationally faint because of fallback ofsimilar to the weak Type IIp SNe. In the direct black hole regime no ‘‘ normal ’’ (non–jet-powered) supernovae occur since no SN shock is launched. Antion are pulsational pair-instability supernovae (lower right-hand corner; brown diagonal hatching) that launch their ejection before the core collapses.
w and to the right of this we find the (nonpulsational) pair-instability supernovae (red cross-hatching), making no remnant, and finally another domain
e black hole are formed promptly at the lowest metallicities and highest masses (white) where nor SNe are made. White dwarfs also do not makenovae (white strip at the very left).

Takashi Yoshida QUCS2012, Nara, December 13, 2012

Stellar Type and Final Mass of Massive Stars
Stellar evolution until C-burning
MMS = 13 - 300 M , Z = 10-4 - 0.02
PPI
Z=10-430

PI SNM(56Ni) > 3 M

Z=0.001
Z=0.004
Z=0.01RG

Z=0.0230(Umeda, TY & Takahashi 2012, PTEP 01A302;
TY, Okita & Umeda, in prep.)

M(56Ni) > 1 M

WO
300
56Ni mass is supposed from the resultsof Umeda & Nomoto (2008)
Very massive stars (MMS > 100 M )0.001<Z<0.01
WO stars with large CO core~
Possibility for Type Ic super-luminous (SL) SNe

Z<0.001~

Type II(n?) SLSNe or Type Ic SLSNe through PPITakashi Yoshida QUCS2012, Nara, December 13, 2012

CO Core Mass of Very Massive Stars
Some SLSNe may have evolved from very massive stars.
Stellar evolution calculation for MMS = 100 - 500 M and Z=0.004.
PISN(TY & Umeda 2011, MNRAS 412, L78).
.
MC=0.5Mst

PISN: SN 2007bi.
.
MA=Mst
.
.
MB~1.5Mst M(56Ni) > 3 M
M(56Ni) > 1 M

Three cases of mass loss rates.
.
M. A: standard. (Mst)
MB ~ 1.5 Mst(WR stars: Crowther 2007).

.

MC = 0.5 Mst(e.g., Discussion in Hirschi 2008,Pulse et al. 2008)

Core-collapse SN Ic with M(56Ni)>3M

A: 110 < MMS < 270 M
SLSN 2007bi is a candidate of ~100M pair-instability SN (Gal-Yam et al. 2009)
MMS > 300 M with small mass loss (C)Takashi Yoshida QUCS2012, Nara, December 13, 2012

Pulsational Pair-Instability
MMS = 250 M , Z=0.004

Mf = 61.1M(TY, Okita & Umeda, in prep.)

Pulsational pair-instability occurs in stars with MCO ~ 40-60 M(e.g., Heger & Woosley 2002, Umeda & Nomoto 2008)

After some pulsations, the star collapses to become SN.
Eruptive mass loss will be included in a future study.
(e.g., Woosley et al. 2007, Chatzopoulos & Wheeler 2012)
Takashi Yoshida QUCS2012, Nara, December 13, 2012

Aspherical SN Explosion of Very Massive Stars(TY, Okita & Umeda, in prep.)
M(56Ni) = 3.5 - 7.4 M
Pair-instability SN or Core-collapse SN?
Explosive nucleosynthesis during aspherical core-collapse SN explosion
Solid lines: Mf=61.1M , MCO=56.2M , E=7×1052 erg (MMS=250M )Dashed lines: Mf=43.1M , MCO=38.8M , E=5×1052 erg (MMS=110M )SLSN 2007bi

56Ni in SN 2007bi
M(56Ni)Smaller θop

Smaller M(56Ni)

Mej/10More massive progenitor
Larger explosion energy
Aspherical SN explosion reproduces
M(56Ni) of SN 2007bi.

JetSpherical
Takashi Yoshida QUCS2012, Nara, December 13, 2012

Progenitor for Electron-Capture Supernova
Electron-capture SN (ECSN)
Lower mass limit of supernova
Evolution of a progenitor for ECSN (Takahashi, TY & Umeda, in prep.)
Propagation of deflagration front
Material behind the front becomes to nuclear statistical equilibrium.
0.5

10.2

electron mole fraction Ye

10log T (K)

9.8
9.6
9.4
9.2
90.45

0.4

0.35

t = 0.048, 0.1, 0.2, 0.3, 0.4 s
after the O-ignition

8.8
8.6

0.3

00.1

0.2

0.3

0.4

Mr/M!

0.5

0.6

0.7

0.8

00.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

Mr/M!

Next Step
Hydrodynamical simulation of SN explosion
For details, please see Poster A03-P27
Core collapse of an ONe core: The progenitor of ECSN
Takahashi, TY, & Umeda
Takashi Yoshida QUCS2012, Nara, December 13, 2012

Rotating Star Model
Mass coordinate as isobar Mr → MP(e.g., Endal & Sofia 1976, Meynet & Maeder 1997, Heger, Langer, & Woosley 2000)

Radius rP is determined from the volume enclosed by isobar surface
1/33rP = ( 4πVP)
GMP∂P =fP
44πr∂MPP∂rP = 1Centrifugal∂MP 4πrP2ρ
gravity force∂ ln T = min(∇ad, ∇rad fT )fP
∂ ln P∂LP = ε - ε + εΩ(MP)nuclgrav
ν.∂MP .
MP: P constant M(Ω) = M(Ω =0) ( 1 )0.43
1 -v/vcrit.
.
J = jenv M
fT, fP: Correction factorsr(r0,θ) = r0 {1 - ε(r0) P2(cosθ)}Transport of angular momentum and rotation-induced mixing(Heger, Langer, & Woosley 2000)
are also taken into account.
Takashi Yoshida QUCS2012, Nara, December 13, 2012

Rotating Massive Star
MMS=15M , Z=0.02, vrot=200 km s-1
1H,4He,12C,16O,20Ne,“Si”,“Fe”

15 M , Z=0.02 vrot=200km s-1 Star
“Si”

“Fe”

4He
20Ne
12C

1H

vrot=200 km s-1
vrot=0 km s-1

16O

Rotating (non-rotating) star
Mf = 12.7 (13.9) M
MHe core = 5.28 (4.27) M
MCO core = 3.18 (2.27) M
MFe core = 1.66 (1.47) M
r(r0,θ) = r0 {1 - ε(r0) P2(cosθ)}
Takashi Yoshida QUCS2012, Nara, December 13, 2012

Summary
Massive star evolution model (TY & Umeda 2011, Umeda, TY & Takahashi 2012)
Very massive stars (MMS ~> 100 M ) for super-luminous SNe (SLSNe)
0.001<Z<0.01~

WO stars with large CO core
Possibility for Type Ic SLSNe
Type II(n) SLSNe or Type Ic SLSNe through PPIZ<0.001~
Aspherical core-collapse SN explosion for SLSN 2007bi
110, 250M models with large explosion energy
56Ni amount consistent with SN 2007bi
Evolution of ONe core to become ECSN
Up to deflagration by the ignition of O-burning
See Poster A03-P27, Takahashi, TY & Umeda

Rotating massive star model
Test of 15 M , vrot = 200 km/s model up to the onset of core-collapse
Takashi Yoshida QUCS2012, Nara, December 13, 2012