New ways to explode stars Introducing the Palomar Transient Factory

1. New ways to explode starsIntroducing the Palomar Transient Factory Avishay Gal-Yam, Weizmann Institute of Science Hubble Fellows Symposium 2010

2. Cosmic Explosions Type II, Ib, Ic Supernova Type Ia Supernova SN 1994D, Challis SN 1987A Short GRB Long GRB ? GRB 980425, Galama et al. 1998 SHB 050709, Fox et al. 2005

3. Type Ib (UCB; CCCP) Graham & Li 2005 New explosion #1: SN 2005E LOSS discovery Member of the Ca-rich Subclass (Filippenko et al.) Hagai Perets, Nature, in press Dave Arnett, Paolo Mazzali, Daniel Kagan, UCB SN group, CCCP, Anderson & James, Ofek, Bildsten & Co., Quataert & Co.

4. A massive star? No star formation to deep limits … unlikely also on theoretical grounds r<25.3 (25.9) at 3(2)  Perets et al. 2009

5. 22.9 kpc 11.3 kpc A hyper-velocity SN (HVSN) ? Life in the fast lane? SN 2005E Not likely: chances to observe HVSNe with LOSS are < 1/100

6. Mazzali So what, then? What will nebular spectra reveal? Peculiar abundances (C, O, Ca, Ni56) = (0.1 0.037 0.135 0.003) solar Total ejected mass is <0.3 solar !

7. Not a single event! 6-10 additional siblings, additional early hosts

8. What can it be? A double WD (O/Ne+He): accretion induced collapse ?

9. } Models by Arnett Nucleosynthesis Can you make so much Ca with no Si and S? (Ca/S >6) * No (if you burn C/O) * Yes (if you burn He) He/C/O accretion/merger result an emerging field

10. New Explosion #2: Pair Instability Supernovae (PISNE)(Barkat, Rakavi & Sack 1967 ; Heger & Woosley 2002; Waldman 2008 …) * Helium cores above ~50 solar masses become pair unstable * In these low-density high-T cores, e+e- wins over oxygen ignition, heat is converted to mass and implosion follows * Inertial oxygen ignition leads to explosion and full disruption Waldman * “This is a uniquely calculable process” (Heger & Woosley 2002); “this is a trivial calculation” (Barkat 2009); “Pretty neat homework problem” (Gal-Yam 1996) “Smoking gun”: Core mass > 50 solar

11. SN 2007bi=SNF20070406-008(PTF “dry run”) * Type Ic SN similar to SN1999as. No interaction, no dust, v=12000 km/s * Luminous peak (-21.3), slow rise (~77 days), 56Co decay * 4-11 solar masses of 56Ni, ejected mass ~100 solar, Ek~1e53 (scaling) * Well-fit by models (Kasen) Core mass > 50 robustly established; Gal-Yam et al. 2009, Nature, 462, 624; also Young et al. 2009

12. Implications(Gal-Yam et al. 2009) * A helium core ~100 solar detected at Z ~ SMC * Mass loss models are wrong * PISNe happen locally, Universally, models are ~ok * Dwarfs have stars above Galactic limit (>200 solar, probably) * Hydrogen efficiently removed (pulsations?)

13. NS BH BH No remnant ? W-R = Ib/c? “The gap” “rare IIs”? The Core-Collapse Spectrum Lower mass limit unclear: <7..11 solar; stable C/O core EC SN? RSG=II-P HNe, GRB AIC LBV=IIn PP SNe M: 7-11 M: 8-16 M: 17-25 M: 25-30 M: 40-50 M: 50-150 M> 150

14. And now: news from The Palomar Transient Factory There is nothing like searching, if you want to find something. You usually find something, if you search, but it is not always quite the something you were after. Thorin Oakenshild

15. Luminous blue SNe (Quimby)

16. Shocking news (Ofek)

17. Baby Supernovae: the first days Core-collapse SNe: Arcavi SNe Ia: Nugent, Sullivan, Howell, Ellis

18. Supernovae: dwarf vs. giant hosts Arcavi; HST SNAP survey

19. Follow-up is key … GRB-supernova?

20. Thanks

21. Concept:SN 2007bi - “lessons”