Alternative Supernova Energy Sources

Alternative Supernova Energy Sources

Jason Dexter (with Dan Kasen)UC Berkeley & LBNL

Physics of Astronomical Transients 2

Weird Supernovae

core collapse supernovae

after Dan Kasen

Type

Ia2002bjptf10bhp

2008ha

2008es

2007bi

2005apptf09cnd

scp06f6

2006gy


Supernova Explosions

• Diffusion:

• Peak luminosity (Lp) from energy deposition at peak time (tp)


Powering Supernova Light Curves• Thermal

• Radioactive (56Ni)Branch & Tammann (1992)

Kasen & Woosley (2009)Efficiency


Interactions

• Interaction of ejecta with material at large radius resets internal energy

• Large if Rsh >> R0

Woosley+07

Efficiency


Magnetar Spindown Power


Magnetar Spindown Power

Kasen & Bildsten (2010)


Accretion Energy

• Powers brightest sources in the Universe (AGN, GRBs)

• Need: disk, Mfb, outflow Alexander Tchekhovskoy


Accretion in core-collapse SNe

• Collapsars (“failed”)– Type I (long GRBs, Woosley 1993)– Type II/III (long gamma-ray

transients, Quataert & Kasen 2012,

Woosley 2012)• Fallback (successful)

– Early: nucleosynthesis & neutrinos (Fryer et al.), type Ibc? (Lindner et al.)

– Late: still significant energy?

Zhang et al. (2008)


Semi-analytic Fallback Model

• “Explosion”– Matzner & McKee (1999)

shock velocity evolution• Free-fall: t6/n-3 for power

law density profile• Asymptotic: t-5/3

• Reverse shock at H/He– Analogous to SNR


Possible Outcomes• Stellar progenitors from Woosley et al. (2002)• Range of explosion energies

Solar Ultra Zero


Possible Outcomes


Possible Outcomes

No H and/or He

“Collapsars”Reverse Shocks

“Standard”


Caveats• Pressure effects?• Angular momentum

– Outflow turns on when J > Jc?

• Outflow disrupts remaining material?– Collimation? Accretion turns off after disk forms?

• Energy deposition in ejecta?– Similar to magnetar case

Alternative Supernova Energy Sources

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