Models for super-luminous supernovae
Jason Dexter (with Dan Kasen) UC Berkeley Op cal 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 Op cal 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 • Radioac ve ( Ni) Branch & Tammann (1992)
(tp/tnuc) ✏nucMnuce Lp = tp
GGI Neutron Stars 5 Circumstellar Interac on
• Interac on 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 Accre on Energy
2 Lp = ✏M˙ (tp) c 2 ✏Mfbc ⇠ tp
• Need: disk, M , ou low Alexander Tchekhovskoy
GGI Neutron Stars 8 Fallback in a supernova explosion
GGI Neutron Stars 9 Fallback accre on rate
Wong+2013
GGI Neutron Stars 10 Accre on powered supernovae • Accre on 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 deposi on in ejecta 10 Outflow unbinds fallback • As in collapsar GRBs: Outflow escapes ejecta – Disk forma on
– Ou low proper es Outflow Opening Angle (degrees) 1 – Interac on 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 veloci es, but not unique
Inserra+2013 Chatzapoulos+2012
GGI Neutron Stars 13 Signatures of central engines • Central engine should “shine through” • Sources of thermaliza on: – Free-free (IR), lines (op cal), photoabsorp on (UV/so X-ray), Compton sca ering (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 mes
Kotera+2013
GGI Neutron Stars 15 So X-ray flash? • Pulsar could completely ionize ejecta near peak, allowing X-rays to escape
Metzger+2014 GGI Neutron Stars 16 Op cal/UV colors • Excess UV from early ioniza on of He, O • Sharp drops in op cal from loss of thermaliza on 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 interac on, neutron star or black hole central engines • Observa onal signatures of central engine (esp. magnetar) • Possible informa on about final stage of stellar evolu on and/or compact object birth GGI Neutron Stars 18