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Explore Hyper Metal-Poor Stars, Supernovae of Population III Stars, and comparison with observed stars. Dive into 1-Dimensional Mixing-Fallback model and 2-Dimensional Jet model to analyze abundance data from nucleosynthesis calculations.
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Nucleosynthesis in Population III Supernovae and Abundance Patterns of Hyper Metal-Poor Stars N. Tominaga, H. Umeda, K. Maeda, K. Nomoto (Univ. of Tokyo), N. Iwamoto (JAERI)
Contents • Hyper Metal-Poor stars • Supernovae of Population III stars • Comparison with abundance patterns of observed stars • 1-Dimensinal Mixing-Fallback model • 2-Dimensional Jet model
Metal-Poor Stars [Fe/H]= log10(N(Fe)/N(H)) -log10(N(Fe)/N(H))8 • Hyper Metal-Poor (HMP): • Ultra Metal-Poor (UMP): • Extremely Metal-Poor (EMP) : • Very Metal-Poor (VMP): • Solar: [Fe/H] < -5 [Fe/H] < -4 [Fe/H] < -3 [Fe/H] < -2 [Fe/H] ~ 0 (Beers & Christlieb 2005) Compare with results of nucleosynthesis calculations.
Metal-Poor Stars-2 • Reflect abundance patterns of the early Universe • The abundance patterns of ejecta from Pop III or Pop II SNe • A gap exists between EMP stars and HMP stars. HMP • [Fe/H] < -3 stars: • Individual SN yields • [Fe/H] ~ -2.5 stars: • IMF integrated yield of PopIII (or EMP) SNe UMP C-rich EMP EMP
Population III Supernovae Pair-Instability Supernovae 140~300M8 Evolution H He Observationally no evidence H,He O Si Fe Pop III stars 11M8~130M8 BH/NS Core-Collapse Supernovae
Mass Cut Mcut Explosion and Mass Cut Shock Propagation Post-shock T T∝R-3/4E1/4 Fe • High T (T>5×109K) • Fe,α,Ti,Zn,Co,V • Middle T (>T>4×109K) • Fe,Si,Cr,Mn • Low T (>T>3×109K) • Si The boundary between the ejecta and the central remnant
Hypernova and faint SN Nomoto et al. 2003 (astro-ph/0308136) Hypernova Branch Faint SN Branch
Comparison with Abundance Patterns of Observed Stars • HMP stars • HE0107-5240 (Cristlieb et al. 2002) • HE1327-2326 (Frebel, Aoki, et al. 2005) • C-rich EMP stars • CS29498-043 (Aoki et al. 2004) • EMP stars • -4.2<[Fe/H]<-3.5 (Cayrel et al. 2004) • VMP stars • -2.7<[Fe/H]<-2.0 (Cayrel et al. 2004)
EMP Stars -4.2<[Fe/H]<-3.5 Hypernova Model: M=25M☉, 2×1052erg Tominaga et al. 2005
Mixing-Fallback Model Mixing region Fallback Fe BH Mixing Region f : ejection factor Mixing Umeda & Nomoto 2002 Fallback
EMP Stars M=25M8,1×1051erg Normal SN -4.2<[Fe/H]<-3.5 f=0.1 Hypernova Model: M=25M☉, 2×1052erg Tominaga et al. 2005
C-rich EMP Stars CS29498-043 f~10-3 Model: M=50M☉, 5×1052erg Umeda & Nomoto 2005
VMP Stars -2.7<[Fe/H]<-2.0 Model: Z=0 IMF integrated (11~70M8) Tominaga et al. 2005
Conclusion (Mixing-Fallback model) Faint SN Normal SN + Hypernova Faint SN Hypernova ~ ~
Massive Stars Explosion • Massive stars (M>25M8) • Spherical explosion • Never succeeded, except for Wilson 1985 • Jet-like explosion • Collapsar Model (MacFadyen, Woosley, & Heger 2001) BH/NS
Jet-induced explosion Tominaga et al. 2005 Jet Jet • Hydrodynamics of relativistic jets • Nucleosynthesis BH BH Progenitor cf. Collapsar model (MacFadyen, Woosley, & Heger 2001) MMS=40M8 . Mcut (Mcut=1.75M8) θjet (θjet=5°) vjet (vjet=0.98c, Γjet=5) Ejet (Ejet= Ejet×tjet=1.5×1052erg) fth (fth=Eth/ Ejet=10-3) Ejet: Energy injection rate (Rotation etc.) .
Multi-dimensional relativistic hydrodynamics ←Lorentz factor Conserved quantity (D,S1,S2,S3,τ) ←Density ←Momentum ←Energy ←Equation of continuity ←Conservation of momentum ← Conservation of energy ¨ Marti & Muller 1994
Density structure 1s after 3s after 5s after 10s after
Fallback-Ejection 1D: ejection factor f 2D: Ejet . He Jet materials : O/C Jet fallen-back materials ejected as jets O/Mg Si stellar materials : Fallback Fe materials outside the fallback region
After explosion (100sec) log scale Jet materials 12 Fe Density structure 11 Fe Stellar materials linear scale Fallback 10 10 10.5 11 11.5 12 log10(R)
. . Ejet↓: Fallback↑ M(Fe)↓ [X/Fe]↑ Dependence: Ejet . . Ejet,51=Ejet/1051erg/s . . Ejet,51=15 Ejet,51=0.3 He O/C O/Mg Si Fallback Fallback Fe
. . Ejet,51=1 C-rich EMP stars CS29498-043 Dependence: Ejet . EMP stars Ejet,51=15 -4.2<[Fe/H]<-3.5
Conclusion (Jet Model) C-rich EMP Abundance ratio [X/Y] . • MP stars • EMP stars: Ejet,51=15 • C-rich EMP stars: Ejet,51~1 • HMP stars: Ejet,51=0.15 • UMP stars (-5<[Fe/H]<-4) • EMP stars: Ejet,51>1 • HMP stars: Ejet,51<0.5 . . HMP Ejet,51 EMP . M(Fe)star M(Fe)jet EMP UMP Fe Mass [M8] . Few stars . HMP . Ejet,51
Summary • Both of the 1D & 2D models can reproduce the observations. . . . . • The properties of 2D Jet model • The f in 1D model corresponds to the Ejet. • The absence of UMP stars can be understood by the narrow range of Ejet. . .