1 explosive nucleosynthesis in neutrino-driven, aspherical pop. iii supernovae shin-ichiro fujimoto...
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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
4
-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