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New Classes of Super-Luminous

Supernovae

Shri Kulkarni & Robert QuimbyCaltech, Pasadena

Stellar Evolution (Old Story)

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ZAMS Mass (Mo) Ending<8 C+O White Dwarf8 to 10 Electron Capture -> Neutron Star (:)10 to 25 (say) Fe core -> Neutron Star>25 Fe core -> Black Hole

Note: 1. Neutrino driven explosions can at

most produce 1 Bethe (1051 erg)2. If so, supernovae with >1Bethe must

have a central engine or a pure thermonuclear event

Exotic Endings

• The central object is an active source of energy– Magnetar (highly magnetized neutron star)– Collapsar (rotating black hole – Gamma Ray Bursts)

• Pair Instability supernovae – Expected ending for massive stars (100 Msun)– The most massive thermonuclear explosions in the

Universe– Do not expect such events at low redshift

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4Robert Quimby

SN 2006gy

Smith et al. 2008

Peak absolute magnitude nearly -22

Brighter than -21 mag for ~100 days

Integrated light >1051 erg See: Ofek+ 2007, Smith+ 2007,

Smith & McCray 2007, Agnoletto+ 2009, Kawabata+ 2009...

50 kpc

~600 pc

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SN 2007bi: Pair Instability SN

Optical light curve decay rate consistent with the production of ~7 M of 56Ni

Iron abundance in nebular spectra also consistent with the decay of ~4-7 M of 56Ni (Gal-Yam 2009)

Gal

-Yam

et

al. 2

009

Palomar Transient Factoryhttp://www.astro.caltech.edu/ptf

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P60 classification

telescope

P200 Spectroscopy

P48survey telescope

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2009: PTF Finds Luminous Supernovae

Robert Quimby

PTF09cwl PTF09cnd PTF09atu

Befo

reAf

ter

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Shell Scenario

ejecta and shell both hydrogen poorouter shell expanding at a few 1000 km/senergy injected from with in

Conclusions

• A new class of supernovae ten times brigther and ten times more energy release than ordinary supernovae

• The origin of these supernovae is unclear but likely entirely are the largest thermonuclear explosions in the Universe

• The findings were unexpected• Easy to detect such supernovae with JWST even at

high redshift (z=10). – May have bearing on how the youngest stars in the

Universe die

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