1 Explosive nucleosynthesis in neutrino-driven, aspherical Pop. III supernovae Shin-ichiro Fujimoto (Kumamoto NCT, Japan) collaboration with M. Hashimoto (Kyusyu Univ.), M. Ono (Kyoto Univ.), & K. Kotake (NAOJ) IAU Symposium 279 Death of massive Stars: SNe and GRBs Nikko, Japan, March 17, 2012

2 Outline 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

3 Observed [X/Fe] of MPSs Dispersion C,N,O : large Na to Zn : small Sr,Y,Zr : large Ba,La,Eu : very large Observed [X/Fe] Average with dispersion Sr,Y,ZrBa,La Eu Z=30 Samples: 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/Fe] Atomic number Propeties of SNe during early phase of Galaxy CNO Small dispersion CNO Na to Zn Z=30 Sr,Y,ZrBa,La Eu

4 -2.7< [Fe/H] < -2 1D 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+HNeTominaga07 [X/Fe] ●: average MPSs （ Lai08) ▲: IMF averaged Best Fit Msun, 1.2FOE 1D model with artificial mixing K, Sc,Ti: underproduced Na,Cu: overproduced Heger&Woosley10IMF-averaged [X/Fe]: SNe [X/Fe] Mixing is required for both models

5 Aspherical explosion in supernovae Aspherical explosion could be universal in SNe. Simulation of Aspherical explosion in 2D 15Msun, entropy Marek & Janka km x 800km 1600km x 1600km 1987A (HST) continuumSi CaFe Cas A (Chandra) Si-rich, Fe-poor Jets Hwang+00 Aspherical effects are important for successful explosion

6 Present 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 of nuclei 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 Zsun Abundances of Solar system and SN1987A

7 Change in Ye due to e-,e+ cap. & neutrino abs pNS Isotropic emission Neutrino heating & cooling Computational region Hydrodynamic simulations of SNe Simulations 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

8 Models 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] △ % % % % % %

9 Sc 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 mixing Aspherical effects are essential for the enhancement 15Msun,1.00FOE

10 M(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

11 [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

12 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 -s C-enhanced MPSs (CEMP) CEMP only [Fe/H] Ito 2011 [C/Fe] CEMP-no? [Fe/H] -4-3

13 IMF-averaged abundances [X/Fe] ○: Case1 (Eexp ～ 1FOE or Eexp = Eexp_min) □: Case2 (lower Eexp for lower Mms) ■: Cayrel+04+NLTE effects Case 12 Eexp (11Msun) [1e51erg] Eexp (15Msun) [1e51erg] Eexp (20Msun) [1e51erg] Eexp (25Msun) [1e51erg] Eexp (30Msun) [1e51erg] Eexp (40Msun) [1e51erg] 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/Fe]

14Summary We 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