New high-energy observaons of supernova explosions Brian Grefenste:e SRL, Caltech [email protected] FOE II Raleigh, NC, June 4, 2015 Thermonuclear Supernova • What’s the progenitor? – C+O core plus massive star: • Chandrasekhar limit exceed and igni1on of C in the core. • Sub-Chandrasekhar explosions. – C+O core plus He core: • Double-degenerate mergers. • How does the star explode? – Sub-sonic deflagraon wave or super-sonic detonaon? 2 Thermonuclear Supernova • What’s the progenitor? – C+O core plus massive star: • Chandrasekhar limit exceed and igni1on of C in the core. • Sub-Chandrasekhar explosions. – C+O core plus He core: • Double-degenerate mergers. • How does the star explode? – Sub-sonic deflagraon wave or super-sonic detonaon? 3 Thermonuclear Supernova • What we know: – Op1cal light curve is powered by radioac1ve decay: • 56Ni à 56Co à 56Fe • (6 days) à (77 days) 56Ni – Op1cal emission is highly reprocessed gamma-ray lines. 56Co • Complicated radiave transfer process. • How much 56Ni is uncertain. – X-rays and gamma-rays are simple(r). • Only Compton scaering and photoelectric absopr1on. 4 Core-Collapse Supernova • Collapse of a massive star. • Core collapses un1l a proto-neutron star is formed. • Hard surface causes a “bounce”. • Shock wave blows apart the star. 5 Core-Collapse Supernova • Standard models fails in 1-D. – Spherical symmetry à stalled shock. • Soluons: – Neutrino heang and convec1on (and/or turbulence in 3D). • Leads to lopsided explosions. – Rotaon and/or magne1c fields. • Leads to collimated jets. 6 Core-Collapse Supernova Ott et al • Standard models fails in 1-D. – Spherical symmetry à stalled shock. • Soluons: – Neutrino heang and convec1on (and/or turbulence in 3D). • Leads to lopsided explosions. – Rotaon and/or magne1c fields. • Leads to collimated jets. 7 Core-Collapse Supernova Moesta et al • Standard models fails in 1-D. – Spherical symmetry à stalled shock. • Soluons: – Neutrino heang and convec1on (and/or turbulence in 3D). • Leads to lopsided explosions. – Rotaon and/or magne1c fields. • Leads to collimated jets. 8 Integral 9 • 3.5 Mpc away (roughly 1 / 100 years). • “Run of the mill” Type Ia explosion in op1cal. 10 SN 2014J • 56Co gamma-ray lines detected at ~850 and ~1200 keV • Confirmaon that 0.6 M¤ was produced in the event. Integral Churazov et al. Nature (2014) 11 SN 2014J The and Burrows, arxiv 1402.4806 12 SN 2014J The and Burrows, arxiv 1402.4806 13 SN 2014J • Gamma-rays are Compton down- The and Burrows, arxiv 1402.4806 scaered to hard X-ray energies. • Hard X-rays give clues about the distribu(on of 56Ni in the explosion. • Benchmark “W7” model (from Nomoto et al, 1984) gives a predic1on for hard X-ray flux vs me. Silicon/Magnesium 14 SN 2014J NuSTAR Iron Silicon/Magnesium Harrison et al. (2015), in prep 15 SN 2014J NuSTAR Iron Silicon/Magnesium Harrison et al. (2015), in prep 16 SN 2014J NuSTAR Iron Silicon/Magnesium Harrison et al. (2015), in prep 17 SN 2014J NuSTAR Iron Silicon/Magnesium Harrison et al. (2015), in prep 18 Core Collapse Supernovae 19 Cassiopeia A • Observed soj X-rays tells us about the shocked ejecta. • Doppler maps show complex structure. • Low-energy X-rays only show shocked ejecta, not the true distribu1on of the ejecta. 20 Cassiopeia A • Observed soj X-rays tells us about the shocked ejecta. • Doppler maps show complex structure. • Low-energy X-rays only show shocked ejecta, not the true distribu1on of the ejecta. Delaney et al., ApJ (2010) 21 Core Collapse Supernovae T1/2 ~60 years Iron Silicon/Magnesium 22 Cassiopeia A Grefenste:e et al., Nature (2014) 23 Cassiopeia A 24 Cassiopeia A 25 Cassiopeia A Preliminary! 26 Cassiopeia A Preliminary! 27 Cassiopeia A Preliminary! Grefenste:e et al., (2015) in prep Doppler map of 44TI 28 Cassiopeia A Preliminary! 29 Cassiopeia A Preliminary! 30 Cassiopeia A Preliminary! Fe Doppler Map DeLaney et al. 2010 ApJ 725 2038 31 SN 1987A • Neutrino detec1ons confirmed collapse of the core into a neutron star. • 56Co lines emerged months before expected, heavy mixing of 56Ni. • Low-significance redshi of 500 km / sec detected. Chandra/HST Image: NASA/CXC 32 SN 1987A • Neutrino detec1ons confirmed collapse of the core into a neutron star. • 56Co lines emerged months before expected, heavy mixing of 56Ni. • Low-significance redshi of 500 km / sec detected. Tueller et al, (1990) 33 SN 1987A NuSTAR Boggs et al., Science (2015) 700 +/- 400 km / sec (90 % errors) 34 SN 1987A NuSTAR 35 Summary • Gamma-ray observaons of SN2014J provide an independent confirmaon of 0.6 M of 56Ni is produced in the explosion. • The first hard X-ray observaons of a Type Ia supernova imply a high level of mixing of the 56Ni. – How do we explain this? • Ejecta from core-collapse supernova are intrinsically asymmetric (N=2) and appear to be dominated by large-scale anisotropies. – No jets (yet). 36 Outlook • How do we explain the Fe/Ti differences? – Both created in alpha-rich freezout and/or par1al Si burning, so what’s driving the differences? • Need a link between simulaons (~1 s post- bounce) and ejecta morphology. – 3D turbulence codes coming online soon*, including explosive nucleosynthesis**. • Wait for the next local Type Ia or Type II. 37 .