Supernova Nucleosynthesis Keiichi Maeda Inst. for the Phys. and Math. of the Universe (IPMU), University of Tokyo SNe as the Origin of Elements Up to O (+ s-process) Stellar Evolution IME (Si, Ca…) + Fe + r-process SN Observations in this Talk Supernova (SN) “Expanding metal- rich nebula” SN Remnant Galactic wind →Cluster Galactic chemical evolution Stellar Evolution and Supernovae SNIa CC-SN H-burning WS, 2009.2.19-20 Ia Supernova Classification Thermonuclear exp. of white dwarf H Fe Type II II/Ib/Ic Core-Collapse (CC) of Fe massive stars Ca Fe Si H-richH-rich S Si Type Ia Ca O He HeHe He Type Ib Fe Na Si O C+OC+O Type Ic SiSi FeFe @ maximum brightness (~ a few weeks): – Expanding optically thick medium → P-Cygni. Core-collapse SN – Standard Picture • Core-collapse → proto NS + bounce shock → shock stalled (ram pressure + Fe dissociation) →ν from proto NS (~ 3 ×10 53 erg) →1% of ν deposited, shock revival → explosion w/ ~ 10 51 erg. • Caveat • do not explode in (1D) sims. • Multi-D effects favored. Inside Fe core (typically decoupled from the envelope) Fe core CC-SN Nucleosynthesis Si core O core Before SN • Explosive burning. 3 4 • EK ~ (4π/3) R aT 3 1/4 • T∝(E K/R ) Shock Wave 9 • T9 = T/10 K > 5: Si-burn. 56 Ni, He, Fe -peak • T9 = 4-5: incomplete Si-burn. Si, S, Fe, Ar, Ca • T9 = 3-4: O-burn. O, Si, S, Ar, Ca • T9 = 2-3: C,Ne-burn. After SN Depends on O, Mg, Si, Ne • EK, “mass cut”, and M ms . • + Asymmetry (later). Compact object Ejected (“mass cut”) Mr 56 Ni important in theory & observation • Theory: – Produced in the innermost region. • Observation. – SNe Ia/b/c powered by 56 Ni→56 Co→56 Fe . ~ week ~ 100 days Flow • 8-10M Í • 10 - 20(?)M Í • 20 -100M Í • 100 – 300M Í • >300M Í • White Dwarf 8-10M Í : ONeMg Core-Collapse Nomoto 1984 • Degenerate ONeMg core. – T not reached to neon ignition. – Electron capture →Collapse→NS . • 24 Mg(e -, ν) 24 Na(e -, ν) 20 Ne. • 20 Ne(e -, ν) 20 F(e -, ν) 20 O. Kitaura+ 2006 r [km] • Explosion even in 1D simulations. • Standard ν-driven explosion. • Small binding energy in the envelope + steep density gradient. Trajectories 50 • EK < 10 erg. 56 Kitaura+ 2006 • M( Ni) < 0.015M Í Time [ms] Wanajo+ 2009 ~ 0.002 – 0.004M Í 8-10M Í : ONeMg Core-Collapse Wanajo+ 2009 • Mostly Fe-peak. Log X • Neutron-rich isotopes. • Little IME (density too low in envelope). Log (X/X Í) A Mr 10-100M Í : Fe CC • Simulations do not produce SNe as energetic as observed…, anyway they explode observationally . • 2D/3D effects? Blondin + 2003 “SASI - Standing Accretion Shock Inst.” “Observational” 56 EK and M( Ni) vs. M ms → Mej derived by modeling obs. Mej →Mms assumes evo. Model. The low mass end of CC-SNe? Why matter? • 8-12M Í They may not be dramatic, • 12 - 20(?)M Í but should be numerous. • 20 -100M Í • 100 – 300M Í • >300M Í • White Dwarf Í The low mass end of CC-SNe? From Pre-SN images SN 2005cs, HST Smartt+ 2009 Type II (Wang & Filippenko) Standard IMF→ The low-mass end important The low mass end of CC-SNe? • SN Ib 2005cz in an elliptical. SN Ib 2005cz Kawabata, KM , Nomoto+, 2010, Nature, 465, 326 • Small O/Ca → Small O-core: M ms ~ 8 – 12M Í. 51 56 • EK << 10 erg, M( Ni) < 0.02M Í (ONeMg-CC? Fe-CC?). The low mass end of CC-SNe? • Very faint SN I(?) 2008ha. Valenti+09; Foley+ 09 • A fallback CC-SN model. Moriya+2010 • Mms ~ 13M Í. 48 • EK = 1.2 ×10 erg. • Mej = 0.074M Í. 56 • M( Ni) = 0.003M Í. • NS→BH formation? Mass fractions = M i / M ej (Moriya, Tominaga, Tanaka+ 2010) The low mass end of CC-SNe? SNe II w/ progenitor detected. 08ha? Asymmetry in SN explosions (> 10M Í) • 8-10M Í • 10 - 20(?)M Í • 20(?) -100M Í • 100 – 300M Í • >300M Í • White Dwarf Í Asymmetry – Observations (> 10M Í) KM , Kawabata, Mazzali+ 2008, Science, 319, 1220 [OI]6300 @ 1 year for 18 SNe Observations : Subaru/FOCAS Accumulating evidences… e.g., Polarization ( Tanaka , Kawabata, KM+ 2008, 2009) Nucleosynthesis in “bipolar” CC-SNe Spherical Bipolar Zn, Co Fe( 56 Ni) Mn, Cr O C Zn, Co, Ti →Fe(Ni)→Mn, Cr→O, C Heavier elm. Easier to be ejected. 4/1 − 4/3 Tshock ~ 24E52 r E(isotropic) ↑ → Tshock ↑＆V ↑ V ∝ E / M Nagataki+97; KM+ 2002, ApJ, 565, 405; KM & Nomoto, 2003, ApJ, 598, 1163; Tominaga, KM, Umeda+ 2007, Tominaga 2009 Spherical Bipolar X/X solar X/X solar Zn Ti O O Mg Zn Mg Co Mn Ti Co Mn A A KM & Nomoto 2003 • (Zn,Co,Ti)/Fe↑, (Mn,Cr)/Fe↓ SN→ISM→Star – Similar trends seen in metal-poor halo stars (early chemical evolution). – “Asphericity” may be an important function in understanding the Chemical Evo. – KM & Nomoto 2003; Tominaga, KM+, Umeda+ 2007; Tominaga 2009 20(?)-100M Í : Fe CC “Hypernovae” From Supernovae to Hypernovae. • 8-10M Í • 10 - 20(?)M Í • 20(?) -100M Í • 100 – 300M Í • >300M Í • White Dwarf Í 20(?)-100M Í : Fe CC • “Traditional ” idea: – Mms > 20-30M Í→ BH, No SN . • New Observations : – They do explode . – Energetic – “Hypernovae ” – Sometimes w/ GRBs. “Observational” 56 EK and M( Ni) vs. M ms → Mej derived by modeling obs. Mej →Mms assumes evo. Model. Iwamoto+ 1998 Hypernovae SN 1994I GRB030329 Time SN 1998bw SN Ic 2003dh 1/2 －1/2 Line Width ∝ EK Mej • Some w/ GRBs. Galama+ 1998; Hjorth+2003; Stanek+2003 Hypernova Nucl. syn. • Larger E K – Larger amount of Fe-peak and IME. Xi Xi 51 E51 =E/10 erg=1 E51 =10 Mr Mr Fe-peak IME (Si, Ca…) Nakamura+01, Umeda+02 SN 1998bw Typical SN Asymmetry again KM+, 2006ab [OI] 6300, 6363 1998bw Asp, Z, E 51 =20 Z 1998bw < 30 o R Sph, E 51 =50 • Hypernovae seem to have larger asphericity than others. – Both “Energy” & “asphericity” important in nucleosynthesis. Theory… e.g., Fryer+ 1999 NS or BH? KM+, 2007, ApJ, 658, L5 • Important functions in nucleosynthesis. – Energy, asphericity, “mass cut” vs. M ms . [OI] [CaII] [FeII] [NiII] NS? BH? Transition at ~20M Í? SN 2006aj. 58 M( Ni) ~ 0.05M n-rich ⇒NS formation (?) > 100M Í : PISN and beyond • 8-10M Í • 10 - 20(?)M Í • 20(?) -100M Í • 100 – 300M Í • >300M Í • White Dwarf Fe Collapse 100-300M Í : Pair Inst. SNe Pair • Radiation dominated: P∝ργ=ρ 4/3 • e- e+ creation→Γ<4/3, Collapse 56 →O-burn runway→M( Ni) = 0.05 – 30M Í Metal Poor Stars (Early Universe) No Indication Nearby SNe (Present Universe )? Scannapieco + 2005 Umeda & Nomoto 2002 ~200day! 56 <<Solar M( Ni)~3M Í [Zn/Fe] Solar 6M Í [Fe/H] PISN – Observational counterpart? • SN Ic 2007bi = bright + 56 Ni/Co/Fe heating. Gal-yam+ 2009 56 – Mej > 40M Í, M( Ni) > 6M Í. 07bi – Cons. w/ PISN. Gal-yam+ 2009 Not conclusive yet. Typical SN Ic • CC-SN w/ M ms ~ 100M Í. 07bi Moriya, PISN Tominaga, CC-SN Tanaka+ 2010b Typical SN Ic 100 days 100 days logT Another candidate for a PISN? c • SN IIn 2006gy = bright + interacting. mass loss CSM by pulsational mass loss Not conclusive yet. logρ c SN Interaction Typical SN Ic 100 days PISN CC-SN Pul. PISN Model (Interaction w/ wind) Core-Collapse Model Woosley, Blinnikov, Heger, 07 (56 Ni heating) Kawabata+ 2009 > 300M Í : Fe Core-collapse ~ 300 – 1000M Í Ohkubo+, 2009 at leaving MS Yoshida+, 2008 Log R Different accretion rate Accretion Mass -2 Proto-star core ~ 10 M Í ~ 30 – 100M Í at ZAMS 3 5 Primordial cloud ~ 10 - 10 M Í -3 High Accretion Rate (>10 M Í /year) … Only for “Zero” Metal Fe core for 25M star > 300M Í : Fe CC Fe core for 500&1000M stars Log ρ Fe Collapse Pair Mr/M ms Log T 6 t~2 10 yr ~ 10-30% of M ms ~13 – 25M Í Ohkubo, Umeda, KM+, 2006, ApJ, 645, 1352 Hypothesized exp. [X/Fe] Ohkubo+ 2006 Intra Galactic Medium OK Z 56 • M( Ni)=5M Í Metal-Poor Halo stars • M(Si)=4M Í • M(O)=24M Í • M(He)=280M Í • M(H)=190M Í Never Fit Z • MBH =480M Í Nucleosynthesis ← E, Geometry → M(BH) Atomic Number Thermonuclear SNe (Type Ia) Type Ia SN = Distance ladder • 8-10M Í • 10 - 20(?)M Í • 20(?) -100M Í • 100 – 300M Í • >300M Í • White Dwarf Thermonuclear SNe (Type Ia) • Consensus: – Chandrasekhar-mass white-dwarf (~1.4M Í). –Thermonuclear explosion. –No central object left. 56 –Fe producer, typically M( Ni) ~ 0.6M Í. –Standard candles (luminosity estimate possible). SNe Ia – classical picture Deflagration • Two modes of flames. – Deflagration (subsonic). – Detonation (supersonic). • Favored scenarios: – Pure deflagration. n-rich • e-capture. Def. －Det. – n-rich stable Fe-peak. W7 by Nomoto+ 1984 – Delayed det. (Def. →det.). • Little e-capture (Ye = const.). – 56 Ni/stable-Fe set by progenitor. • C, O-burning outside. Khokhlow 1991; Iwamoto+ 99 KM, Taubenberger, Sollerman+ 2010, ApJ, 708, 1703 Asymmetry • “Off-set ” ignition. • Doppler shifts in late-phases. • Solves “unresolved” spectral diversity. Fe -peak elements Deflagration Detonation deflagration time detonation KM, Roepke, Fink+ 2010, ApJ, 712, 624 (cf. Kasen+ 2009) Asymmetry • “Off-set ” ignition. • Doppler shifts in late-phases. Branch+ 1988; Benetti+ 2005 • Solves “unresolved” spectral diversity. Si II absorption velocity Si II absorption velocity / day HVG HVG LVG LVG Days Decline Rate = Luminosity indicator • Spectral evolution do not correlate with the “luminosity”.