Models for super-luminous supernovae Jason Dexter (with Dan Kasen) UC Berkeley OpAcal transients then 1045 ) 44 -1 10 43 10 core collapse supernovae 1042 Peak Luminosity (ergs s 1041 after 10 100 M. Kasliwal, D. Kasen Light Curve Duration (days) GGI Neutron Stars 2 OpAcal transients now 1045 scp06f6 2005ap PS1-10jh 2008es ) 44 2006gy -1 10 PS1-11af 2007bi 1043 2002bj core collapse ptf10bhp supernovae 1042 Peak Luminosity (ergs s 2008ha 1041 after 10 100 M. Kasliwal, D. Kasen Light Curve Duration (days) GGI Neutron Stars 3 Supernova light curves > 1044 ergs / s Gal-Yam et al. GGI Neutron Stars 4 Powering supernova light curves • Thermal Kasen & Woosley Efficiency (2009) E0 R0 Lp = tp vtp 56 • RadioacAve ( Ni) Branch & Tammann (1992) (tp/tnuc) ✏nucMnuce− Lp = tp GGI Neutron Stars 5 Circumstellar InteracAon • InteracAon of ejecta with material at large radius resets internal energy Efficiency E0 Rsh Woosley+07 Lp = tp vtp • Large if Rsh >> R0 GGI Neutron Stars 6 Magnetar Spindown Power 2 1 P − E I ⌦2 1050 ergs rot ⌘ 2 ns ' 10ms ✓ ◆ 2 2 E B − P t rot 1 yr m ⌘ L ' 1014G 10ms mag ✓ ◆ ✓ ◆ Erot tm Lp Kasen & ⇠ tp tp Bildsten (2010) 2 2 43 B − tp − 1 5 10 ergs s− ' ⇥ 1014G 100d ✓ ◆ ✓ ◆ GGI Neutron Stars 7 Accreon Energy 2 Lp = ✏M˙ (tp) c 2 ✏Mfbc ⇠ tp • Need: disk, MY, oulow Alexander Tchekhovskoy GGI Neutron Stars 8 Fallback in a supernova explosion GGI Neutron Stars 9 Fallback accreAon rate Wong+2013 GGI Neutron Stars 10 AccreAon powered supernovae • AccreAon disk wind collides with ejecta, deposits energy Dexter & Kasen (2013) SN 2008es SN 1998bw 1045 SN 2008D 44 SN 2010X 10 ) -1 ) -1 1044 1043 1043 42 Luminosity (ergs s 10 42 10 R < 10 Rsun Peak Luminosity (ergs s 10 Rsun < R < 30 Rsun 30 Rsun < R < 300 Rsun R > 300 Rsun 51 E < 10 ergs 1041 1041 E > 1051 ergs 10 100 0 20 40 60 80 100 Time to Peak (days) Days since explosion GGI Neutron Stars 11 Open Issues • Fallback rate • As in magnetar model: Outflow trapped in fallback – Energy deposion in ejecta 10 Outflow unbinds fallback • As in collapsar GRBs: Outflow escapes ejecta – Disk formaon – Oulow properes Outflow Opening Angle (degrees) 1 – InteracAon of outgoing, 1 10 100 infalling material Time (days) GGI Neutron Stars 12 Evidence of central engines? • Magnetar model explains many Type I SL SN light curves, high velociAes, but not unique Inserra+2013 Chatzapoulos+2012 GGI Neutron Stars 13 Signatures of central engines • Central engine should “shine through” • Sources of thermalizaon: – Free-free (IR), lines (opAcal), photoabsorpAon (UV/soi X-ray), Compton scaering (high energy) Kotera+2013 GGI Neutron Stars 14 Hard X-rays, gamma rays • For low field strengths, can be significant high energy emission at late Ames Kotera+2013 GGI Neutron Stars 15 Soi X-ray flash? • Pulsar could completely ionize ejecta near peak, allowing X-rays to escape Metzger+2014 GGI Neutron Stars 16 OpAcal/UV colors • Excess UV from early ionizaon of He, O • Sharp drops in opAcal from loss of thermalizaon Dexter & Kasen, in prep. Inserra+2013 4 3 ergs / s) 44 2 1 luminosity (10 0 0 100 200 300 400 time (days) GGI Neutron Stars 17 Summary • New classes of supernovae – (some) superluminous require new energy source • Models: circumstellar interacAon, neutron star or black hole central engines • Observaonal signatures of central engine (esp. magnetar) • Possible informaon about final stage of stellar evoluAon and/or compact object birth GGI Neutron Stars 18 .