Core-Collapse Supernovae and Abundances in Extremely Metal-Poor Stars Keiichi Maeda Dept. of Astronomy, School of Science, Univ. of Tokyo SN 1998bw (Hypernova) SN 1987A = E ~ 30×1051ergs E ~ 1×1051ergs Explosion Mechanism? Nucleosynthesis? Galactic Chemical Evolution? 1 Contents • Introduction – Stellar evolution & supernovae • Observational properties of hypernovae – Spectra and light curves (Optical) • Evidence of asphericity and black Hole formation in hypernova explosions • Jet-induced explosion model – Hydrodynamics of jet propagation – Growth of a central black hole – Nucleosynthesis • Abundances in metal-poor stars and early Galactic chemical evolution – Contribution of hypernovae SNIa Evolution of Stars SNII/Ib 2 SNe Ia: Accreting White Dwarfs SD Scenario DD Scenario orbit shrinks WD GWR WD WD GWR companion accretion disk accretion from thick disk NS SNeIa 3 Core-Collapse SNe: Massive Stars Delayed Neutrino Explosion Model Marginally Explains Energetic of (Normal) Core-Collapse SNe (1051ergs) e.g., Janka et al. 2002 4 Fate of Massive Stars • ～１２－２5M~: Core-Collapse Supernovae （Neutron Star Formation） • ～２5－１００？M~： Supernovae/Hypernovae （Black Hole Formation?） • ？－１3０？M~： Direct Collapse to a BH （Black Hole Formation?） • ～１4０－２７０M~： Pair Instability SNe (PISNe) (No Central Remnant) • ～３００M~以上: Direct Collapse to a BH? BH + Explosion? Cycle in the Galaxy/Universe 5 Abundances in Halo-Stars and Galactic Chemical Evolution [X/Y]=log(X/Y) – log(X/Y) [X/Fe] ISM Heavy Elements Core-Collapse SNe SNe Ia Stars -1 0 1 0 -1 -4 -2 0 [Fe/H] Supernovae Mass loss Time More Massive Stars 6 Observational Properties of Hypernovae Spectra of Supernovae & Hypernovae Ic: no H, no strong He, SiII Ia no strong Si O Ca He Ib Hypernovae： Ic broad features 94I blended lines Hyper 97ef -novae “Large mass at 98bw high velocities” 7 Classification of Supernovae Ia -- Si line -- Exploding WD SNI -- no H Ib -- He lines SN Ic -- no He, Si -- Core-Collapse SNII -- H line ･Evolution of Massive Stars (Mass Loss) C/O Fe Ic Mass Loss H He Mass Loss C/O Ib H ⇒⇒He PreSN H He C/O II Light Curves of Supernovae & Hypernovae Light Curve Broadness SN1998bw >> SN1994I Ejected Mass SN1998bw >> SN1994I Progenitor’s Mass SN1998bw >> SN1994I 8 CO Star Models for SNeIc Parameters [M , E, M(56Ni)] H-rich ej He Light Curve Spectra ５６Fe 1/2 E ∝ Mej τ ~[τdyn • τdiffusion] C+O 56 1/2 Co R κ Mej ~• M Si VR c C+O 56Ni Fe ∝κ½M ¾E -¼ Collapse ej ５６Ni E ∝ M 3 Mms/M~ MC+O/M~ ej ~40 13.8 ~35 11.0 ~22 5.0 Spectral Fitting: SN1997ef Model Normal SN Small Mej Too Narrow Features 9 Spectral Fitting: SN1997ef Model Hypernova Large Mej Broad Features Hypernova Candidates × 51 Ekinetic > (5-10) 10 ergs SN 1998bw SNe Ic SNe IIn SN GRB SN GRB 1998bw 980425 1997cy 970514 1997ef 971115 1999E 980910 1999as 1988Z GRB 980425 2002ap 1999eb 991002 1997dq 1998ey 1992ar 10 Progenitors’ Mass – E – M(56Ni) Evidence of Asphericity and Black Hole Formation in Hypernova explosions 11 2 2 53 Egrav ~ GMREM /RREM ~ G(1.5M) /(10km) ~ 6×10 ergs Egrav / ESupernova ~ 0.002 ; Marginally attained in simulations. Egrav / EHypernova ~ 0.02 (NS), 0.002 (BH) ; ??? Jets in the Universe L1551-IRS5 v4641 Sgr SUBARU/NAO Hjellminget et al. VLA/NRAO Young Stars Stellar Mass Black Holes 3C175 Centaurs A Bridle NASA/CXC/SAO VLA/NRAO/NSF AURA/NOAO/NSF Galaxies Quasars 12 1) Asphericity in Core-collapse SNe (in general) SN1987A: Asymmetrical, but not spherical, ejecta Optical Polarization in core-collapse SNe > 0.5 % (in SNe Ia < 0.2 - 0.3%) HST Image of SN1987A Optical Spectropolarimetry of Wang et al. 2002 SNe 1993J, 1996cb, Wang et al. 1999 2) Light Curves of Hypernovae -20 -20 1998bw 1998bw -19 -19 -18 -18 -17 -17 -16 -16 -15 -15 Bol Bol 0 25 50 0 25 50 -14 1997ef -14 1997ef -12 2002ap -12 2002ap Co -10 -10 0 100 200 300 400 500 0 100 200 300 400 500 Time [day] Time [day] Low Density High (Vacuum) Density Spherical Hydro Model Maeda et al. 2003, ApJ, submitted 13 3) Late time spectra of SN1998bw Line Width Inversion of Fe and O [OI] 6300A O FWHM FeII] 5200A Fe Observation Spherical Expansion Observer Broader Fe lines than O lines in the observations. [OI] 6300A Interpretation as an FeII] Aspherical explosion 5200A Observation Spherical 56Fe 15 deg 16O Aspherical Maeda et al. 2002 14 4) Optical Polarimetry of SN2002ap 6×10–14 (a) February –14 Feb, 2002 4×10 March Flux 2×10–14 <1% at OI7773 0 2 (b) Outer Region Average in February Ca 1 Average in March O March,2002 % Pol 0 <2% at CaII IR 200 (c) Inner Region 150 100 PA (deg) –16 1.5×10 (d) 0.0018 × Feb Flux 1×10–16 (redshift = 0.23c) 5×10–17 1)Different flux Pol. asphericity in 0 2 (e) Average in February (cont. sub’d) Average in March different depths. 1 % Pol 0 200 (f) 2)The Polarized flux is 150 100 well fitted by radiation PA (deg) 5000 6000 7000 8000 redshifted by 0.23c. Rest wavelength (Å) Kawabata et al. 2002 A Hypothetical ‘Jet’ Interpretation F [λ (1 –Vred/c) ] Observer Pjet (λ) = f ＊ F（λ） Vred = Vjet (1 + cos i) = 0.23 c, Thus Vjet > 0.115c. The jet could be a 56Ni-rich blob. High ionization state is expected. vjet i 15 5) BH Formation in a HN explosion Abundances in Nova Sco [X/H]=log10(X/H)-log10(X/H) 1.5 SN matter 1 BH 0.5 [X/H] 0 NOMgSiSTiFe -0.5 • Enhancement of O,Mg,Si,S,Ti by a factor of 6-10. Israelian et al. 1999 Hypernova model for the formation of the BH in Nova Sco Abundance in Nova Sco BH mass in the model 1 E51=30 0.8 4.8M at the explosion 0.6 SN [X/H] 0.4 0.2 0 5.4M now (Post SN) He C O Ne Mg Si S Ca Ti Fe BH MMS=40, MHe=16, E51=30 MBH at the explosion ~ 5M Black hole formation with Hypernova explosion. Podsiadlowski et al. 2002 16 The properties of hypernova explosions • High velocity material (Fe) • Low velocity & high density material (O) – Contrary to conventional spherical models. • forms a black hole, but explodes with large E51 (>10). – Black hole formation does not always leads to a failed supernova. Do jet-induced explosions satisfy these conditions? Jet-induced explosion model 17 Previous Works Energy Mass cut Yields Input Many Prompt By hand Done 8-300M Spherical E51=1-100 Nagataki Prompt Byhand Done SN1987A 1998&2000 (No Accretion) Aspherical 20M, E51=1 Maeda et al. Prompt By hand Done SN1998bw 2002 (No Accretion) Aspherical 40M, E51=1-30 Khoklov et Jet induced Hydro No 15M, E51=1 al. 1999 (By hand) (By Accretion) This Work Jet induced Hydro Done 20M,40M (By Accretion) (accretion) E51=1-30 Model: Jet-induced Explosion M 16MHe (MMS=40), Rem0 1.0 – 3.0M 8M He (MMS=25), (Nomoto&Hashimoto 1988) 15o Radiation＋Pairs Newtonian Gravity 2 Ejet = ε Mc , 0.01 Postprocessing K. Maeda, in preparation 222 isotopes (Tielemann et al.) 18 Log (Density[g cm-3]) Hydrodynamics Radial Velocity/c Collimated jets (Z) + Bow shock (All direction) R/1010cm M Lateral expansion Density Hydrodynamics (Center) Radial Velocity Accretion from the side R/1010cm Continue to accrete, MBH 19 56 E51=11, MBH(final)=5.9M, M( Ni)=0.11M Outflow Inflow 0.7 s 1.5 s R/1010cm Density Distribution High density core at the central region Jet (R) High velocity material along z Sph (E51=1) Sph (E51=10) Jet (z) (E51=11) 20 Growth of a central remnant MBH 8 Inefficient Jet MREM can be ~ 5 – 10M, starting from 1.5 – 3M. efficient Still a strong explosion 4 Jet follows (E51>10). 0 20 40 Time A hypernova with a stellar mass black hole (sec) (X-ray Novasco; Large Si,S with black hole formation). Final Remnants’ masses and Kinetic Energies 11 6.9 5.9 51 1.9 E51=E/10 ergs MBH(M) • A more massive star makes a more energetic explosion (As seen in ‘Hypernova Branch’). 21 Fe, O Distribution 51 E51（=E/10 ergs）=10, Vz (/109cm s-1) MRem=6M8, 6 56 M( Ni)=0.18 4 2 High Velocity Fe Low Velocity O 0 9 246 0.5 0.1 56Ni(56Fe) 16O 0.01 56 Relation in MREM and M( Ni) Optical L ) (M 40M 20M Efficient (M) inefficient GW: ν GW: ν e.g., rotation 22 Jet-Driven Explosion Model • High velocity material (Fe) • Low velocity & high density material (O) – Contrary to conventional spherical models. • forms a black hole, but explodes with large E51 (>10). – Black hole formation does not always leads to a failed supernova. These conditions can be satisfied. Nucleosynthesis features? Abundances in Extremely Metal-Poor stars and Early Galactic Chemical Evolution 23 Abundances in Halo-Stars and Galactic Chemical Evolution [X/Y]=log(X/Y) – log(X/Y) [X/Fe] ISM Heavy Elements Core-Collapse SNe SNe Ia Stars -1 0 1 0 -1 -4 -2 0 [Fe/H] Supernovae Mass loss Time More Massive Stars 24 Abundances in Extremely Metal-Poor Stars as Relics of SN Explosions in the Early Galactic Evolution Only one explosion likely PopII Star Ｓｈｏｃｋ Ｗａｖｅ produced metal- poor stars Formation with [Fe/H]= –4 ~ –2.5 ☆ [X/Fe]=log(X/Fe)-log(X/Fe)~ ☆ （Ryan et al. 1996, Shigeyama & Tsujimoto 1998, Nakamura, Umeda, Nomoto, Thielemann, Burrows ☆ 1999) PopIII ＳＮ The abundance of these stars are determined by the ☆ nucleosynthesis in individual ☆ Core-Collapse SNe.