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Explosive nucleosynthesis in Explosive nucleosynthesis in neutrino-driven, aspherical neutrino-driven, aspherical

Pop. III supernovaePop. III supernovae Shin-ichiro Fujimoto (Kumamoto NCT, Japan)collaboration with

M. Hashimoto (Kyusyu Univ.),

M. Ono (Kyoto Univ.),

& K. Kotake (NAOJ)

IAU Symposium 279Death of massive Stars: SNe and GRBsNikko, Japan, March 17, 2012

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OutlineOutline Introduction

– Observed abundance ratios of Metal-poor stars (MPSs)

– Spherical models of Pop. III SNe for abundances of MPSs

Hydrodynamics simulations of aspherical Pop. III SNe driven by neutrino

Explosive nucleosynthesis in the Pop. III SNe Comparison of the estimated abundances

with the observed abundances of MPSs

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Observed [X/Observed [X/FeFe] of MPSs] of MPSs

DispersionC,N,O : large Na to Zn : smallSr,Y,Zr : largeBa,La,Eu : very large

Observed [X/Fe]

Average with dispersion

Sr,Y,Zr Ba,La

Eu

Z=30Samples: 28MPS ｓ [Fe/H]=-4.0 : 1 star -4<[Fe/H]<-3 : 8 stars-3<[Fe/H]<-2.6 : 4 stars [Fe/H]>-2.6 : 15 stars

Lai+08

[X/F

e][X

/Fe]

Atomic number

Atomic number

Propeties of SNe during early phase of Galaxy

CNO

Small dispersion

CNONa to Zn

Z=30Sr,Y,Zr Ba,La

Eu

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-2.7< [Fe/H] < -2

1D Pop. III SN model for [X/Fe] of MPSs1D Pop. III SN model for [X/Fe] of MPSs

●: averaged ratios: MPSs （ Cayrel+04)□: IMF average Z=0 1D model SNe: 13,15,18 Msun (1FOE) + HNe: 20,25,30,40,50 Msun (>10FOE) with mixing-fallback N, K, Sc,Ti, Mn: underproduced

IMF-averaged [X/Fe]: SNe+HNe Tominaga07

[X/F

e]

●: average MPSs （ Lai08)▲ : IMF averaged Best Fit

10-100Msun, 1.2FOE1D model with

artificial mixing K, Sc,Ti: underproducedNa,Cu: overproduced

Heger&Woosley10IMF-averaged [X/Fe]: SNe

[X/F

e]

Mixing is required for both models

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Aspherical explosion in supernovaeAspherical explosion in supernovae

Aspherical explosion could be universal in SNe.

Simulation of Aspherical explosion in 2D

15Msun, entropyMarek & Janka

2009800km x 800km

1600km x 1600km

1987A (HST)

continuum Si

Ca Fe

Cas A (Chandra)

Si-rich, Fe-poor JetsHwang+00

Aspherical effects are important for successful explosion

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Present workPresent work Multi-D model of nucleosynthesis

– in SASI-aided, neutrino-driven, aspherical SNe of Pop. III stars– based on 2D hydrodynamic simulations from the core collapse

to the explosion of the stars

Explosion energy, Mass cut, & Mixing– evaluated from the hydrodynamic simulations

Neutrino luminosities & temperatures: Parameters– Proto neutron star is not included in numerical domain

Abundances ofnuclei from C to Zn in

SN ejecta

Compared with observed abundances of metal poor stars (MPSs)

c.f.) Kifonidis+06 and Fujimoto+11 for 15Msun star with ZsunAbundances of Solar system and SN1987A

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Change in Ye due to e-,e+ cap. & neutrino abs.

1200

5000

50000

1.2

2.8

pNSIsotropic emission

Neutrino heating & cooling

Computational region

Hydrodynamic simulations of SNeHydrodynamic simulations of SNeSimulations from the core collapse to the explosion

of Pop. III stars with 11-40Msun (HW10)

using ZEUS2D code (Ohnishi+06)

Non-rotating, zero B-fields stars

Model parameters

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Models with ExplosionModels with Explosion

For progenitors heavier than 20Msun, we have searched more carefully the boundary whether the star explode or not, compared with lighter stars △ = (Lnue_min /Lnue_max w.o.exp.) -1

Models with Lnue <= Lnue_min w.o. exp. do not explode,

While SN explodes promptly and quasi-spherically for Lnue > Lnue_max

Mms[Msun]

Lnue_min [1e51erg/s]

Lnue_max [1e51erg/s]

Numbers of models w. explosion

Lnue_max w.o. explosion [1e51erg/s]

△

11 1.2 6.0 9 1.0 20%

15 2.0 8.0 10 1.5 33%

20 4.3 8.0 9 4.2 2.3%

25 7.0 20.0 10 6.9 1.5%

30 6.0 10.0 13 5.5 9.1%

40 21.0 28.0 6 20.0 5.0%

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Sc production in high entropy bubblesSc production in high entropy bubbles

10000km x 20000km

Aspherical, l=1,2 modes dominant

High entropy ejecta with s > 20kB

Entropy per baryon

[X/Mg]

Enhanced via mixing

Sc and Ti are produced in high entropy bubbles, driven by SASI-induced mixingAspherical effects are essential for the enhancement

15Msun,1.00FOE

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M(Fe) VS Explosion energy of ejectaM(Fe) VS Explosion energy of ejecta

M(Fe) correlate with the explosion energies, Eexp

Faint SNe for 11 and 15 Msun

Hypernovae (HNe) for 25 and 40Msun

M(Fe)

Faint SNe HNe

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[Mg/Fe] VS Explosion energy of ejecta[Mg/Fe] VS Explosion energy of ejecta

[Mg/Fe] are anti-correlate with Eexp

Quasi-spherical Pop. III HNe might be excluded

Low mass Pop. III SNe could be faint SNe

Observed [X/Fe]

of MPSs

▲ Cayrel+04

w. NLTE

■ Cayrel+04

● Preston+06

[Mg/Fe]

HNe

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C-enhanced MPS is a faint SN?C-enhanced MPS is a faint SN?Ito 2011[C/Fe] [Ba/Fe]

20% MPSs = CEMP stars

Large fraction of CEMP stars = s-element rich CEMP stars (CEMP-s star)CEMP-s stars C & Ba from AGB companion in binary

CEMP-no

CEMP -sC-enhanced MPSs(CEMP)

CEMP only

[Fe/H]

Ito 2011

[C/F

e]

CEMP-no?

[Fe/H]-4 -3

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IMF-averaged abundancesIMF-averaged abundances [X/Fe]

○: Case1 (Eexp ～ 1FOE or Eexp = Eexp_min)

□: Case2 (lower Eexp for lower Mms) ■: Cayrel+04+NLTE effects

Case 1 2Eexp (11Msun)[1e51erg]

0.91 0.21

Eexp (15Msun)[1e51erg]

1.00 0.35

Eexp (20Msun)[1e51erg]

1.06 1.12

Eexp (25Msun)[1e51erg]

1.55 2.36

Eexp (30Msun)[1e51erg]

1.09 1.92

Eexp (40Msun)[1e51erg]

6.23 6.23

Salpeter IMF

Explosion energy of adopted models

Atomic number

Observed [X/Fe] are reproduced with IMF-averaged [X/Fe] for both sets, other than Na, K, and Ti

[X/F

e]

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SummarySummaryWe have examined nucleosynthesis in

neutrino-driven, aspherical Pop. III SNe, based on 2D hydrodynamic simulations of SNe

for Pop. III progenitors of 11-40Msun

Low mass, Pop III SNe could be faint SNe Observed [X/Fe], in particuler [Mg/Fe] with small dispersion Origin of C-enhanced metal-poor stars w.o s-elements ?

IMF-averaged [X/Fe] of the ejecta are consistent with observed [X/Fe] of metal-poor stars, other than K, which is underproduced by 0.8dex

Multi-D effects are important for nucleosynthesis Sc and Ti, which are underproduced in 1D spherical models, are abundantly produced in high entropy bubbles