New ways to explode starsIntroducing the Palomar Transient Factory

Avishay Gal-Yam,

Weizmann Institute of Science

Hubble Fellows Symposium 2010

Cosmic ExplosionsType Ia Supernova

Long GRBShort GRB

Type II, Ib, Ic Supernova

SHB 050709, Fox et al. 2005

SN 1987A

GRB 980425, Galama et al. 1998

SN 1994D, Challis

?

New explosion #1: SN 2005E

LOSS discovery

Graham & Li 2005

Type Ib (UCB; CCCP)

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.

A massive star?No star formation to deep limits … unlikely also on theoretical grounds

Perets et al. 2009

r<25.3 (25.9) at 3(2)

A hyper-velocity SN (HVSN) ?Life in the fast lane?

SN 2005E

11.3 kpc

22.9 kpc

Not likely: chances to observe HVSNe with LOSS are < 1/100

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 !

Mazzali

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

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

NucleosynthesisCan you make so much Ca with no Si and S? (Ca/S >6)

*No (if you burn C/O)

*Yes (if you burn He)Models by Arnett}

He/C/O accretion/merger result an emerging field

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

“Smoking gun :”

Core mass > 50 solar

*In these low-density high-T cores, e+e- wins over oxygen ignition, heat is converted to mass and implosion follows

“ *This is a uniquely calculable process” (Heger & Woosley 2002); “this is a trivial calculation” (Barkat 2009); “Pretty neat homework problem” (Gal-Yam 1996)

*Inertial oxygen ignition leads to explosion and full disruption Waldman

SN 2007bi=SNF20070406-008(PTF “dry run”)

Core mass > 50 robustly established;Gal-Yam et al. 2009, Nature, 462, 624; also Young et al. 2009

*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)

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?)

The Core-Collapse SpectrumLower mass limit unclear :

<7..11 solar; stable C/O core

EC SN?

M: 7-11

AIC

RSG=II-P

M: 8-16

?“The gap”

M: 17-25

“rare IIs?”

W-R = Ib/c?

M: 25-30

HNe, GRB

M: 40-50

NS BH

LBV=IIn

M: 50-150

PP SNe

M> 150

BH No remnant

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

Luminous blue SNe (Quimby)

Shocking news (Ofek)

Baby Supernovae: the first days

SNe Ia: Nugent, Sullivan, Howell, Ellis

Core-collapse SNe: Arcavi

Supernovae: dwarf vs. giant hosts

Arcavi; HST SNAP survey

Follow-up is key …

GRB-supernova?

Thanks

Concept:

SN 2007bi - “lessons”