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APCTP-YITP@kyoto. Spin of Stellar Mass Black Holes: Key to Gamma-ray Bursts and Hypernovae. in collaboration with G.E. Brown, R.A.M.J. Wijers, et al. ApJ 575, 996 (2002) ApJ 671, L41 (2007) astro-ph/0612461 arXiv:0801.0477. Chang-Hwan Lee @. Contents. Motivations. GRB.
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APCTP-YITP@kyoto Spin ofStellar Mass Black Holes: Key to Gamma-ray Bursts and Hypernovae in collaboration with G.E. Brown, R.A.M.J. Wijers, et al. ApJ 575, 996 (2002) ApJ 671, L41 (2007) astro-ph/0612461 arXiv:0801.0477 Chang-Hwan Lee @
Contents Motivations GRB Gamma-ray bursts Hypernova Hypernovae Spin of Stellar Mass Black Holes before BH Stellar evolution before BH formation at birth Formation of rapidly spinning BHs key to GRBs & Hypernovae
GRB Two groups of GRBs • Short Hard Gamma-ray Bursts:Duration time < 2 secNS-NS, NS-LMBH mergers • Long-duration Gamma-ray Bursts:associated with Supernovae This talk
Short-hard GRBs GRB hard BATSE Sample • No optical counterpart (?) • Origin • Neutron star merger? • Magnetar flare? • Supernova? short long soft 0.01 1000 1
L-GRB Long-duration GRBs: Afterglow Host Galaxy Association = Distance Estimation
L-GRB GRB/Supernova Association Afterglow GRB980425 SN1998bw
L-GRB Fruchter et al., Nature 441
L-GRB Fraction of fainter or equal pixels SN GRBs are concentrated in the more bright regions of galaxy GRBs GRBs from low metallicity galaxies
L-GRB Kelly et al., arXiv:0712.0430 Type Ic No H, No He consistent with L-GRB afterglow observation
L-GRB Type Ic SN / L-GRB No H, No He line • WR stars: very massive single progenitor ( > 35 Msun) - loss of hydrogen envelope due to strong wind - slow final rotation • Massive progenitors in binaries ( > 20 Msun) - loss of hydrogen envelope due to common envelope evolution - fast final rotation
L-GRB What caused L-GRB/Supernova ? Most-likely Rapidly RotatingBlack Holes Woosley et al. Callapsar: Asymmetric Explosion of a Massive He-Star with Rapid-Rotation
L-GRB How to form rapidly spinning black holes to trigger GRBs/Hypernovae ? Most likely in BH binaries (Soft X-ray Transients) Companion star can keep BH progenitor rotating Formation of rapidly rotating stellar mass BHs
Hypernova Hypernovae in BH binaries (soft X-ray Transients)
Hypernova Observed (visible) Black Holes • Center of galaxies (106-109 Msun) • Intermediate Mass Black Holes (100-104 Msun) • Black Hole Binaries (5-10 Msun) (Soft X-ray Transients ) This talk
Hypernova Discovery of X-ray BH Binaries X-rays Mass accretion from a companion star to a compact object
Hypernova Brightness of Nova Sco 94 (GRO J1655-40) X-ray & Optical Telescopes
Hypernova m=2Msun ; MBH=6Msun Nova Sco 94 [Xi/H]: logarithmic abundances relative to solar Israelial et al. 1999, Nature It’s impossible for normal stars! Where did they come from?
Hypernova Abundances in the secondary of Nova Sco 94 They had to come from black hole progenitor when it exploded. Hypernova to explain the observations.
Hypernova Another evidence ? C.M. System velocity (-106 km/s) : Abrupt Mass Loss by Explosion Mg,Si,S,…
Hypernova Hypernova Explosions from Rotating BH • High Black Hole Mass ( > 5 Msun)--- Maximum Neutron Star Mass < 2 Msun • Evidences of BH Spin in BH Binaries
Hypernova • There are evidences of explosions in BH binaries. • This may indicate that BH binaries are relics of L-GRBs and Hypernovae What is the key to trigger the explosion ?
Black Holes Spin of Stellar Mass Black Holes : key to L-GRBs & Hypernovae
Black Holes Q) How can we understand the population of SXTs ? MS companion 15 10 MBH (Msun) Evolved companion 5 1 10 Orbital period (days)
Black Holes Progenitors • Evolution of BH Progenitor before BH Goal at birth after BH • Evolution of Donor Star Current Observation
before BH Fate of massive stars Mass of Iron CoreNS/BH mass
before BH Fate of massive stars Close binaries Single star H gas No H-shell He He Q) Mass of the Fe core ?
before BH Fe core mass Black Holes Neutron Star In Close Binaries Heger, Woosley et al.
before BH Why sudden increase in Fe core mass at M=20 Msun ? Centeral carbon abudance Single stars Shorten Carbon Burning Time : Sudden Increase in Compact Object Mass
before BH How to form HMBH in Binaries ? • The separation has to be far enough. • They meet after He core burning is finished • Later evolution doesn’t depend much on the existence of H envelope. Super GiantHe-shell burning Red Giant H-shell burning Merge low-mass Fe core high-mass Fe core Neutron Star Black Holes
before BH Case C HMBH Case B NS/LMBH A Schaller et al.
before BH Mass gap between observed NS & BH ? HMBH (5-10 Msun) NS/LMBH (< 3 Msun)
before BH HMBH Formation in Case C NS LMBH HMBH
at birth Rapidly Rotating Black Holes • Tidal interaction : Synchronization of BH-progenitor Spin & Binary Orbital Period • Rapidly rotating BH with large Kerr parameter
at birth Tidal interaction Fe rapidlyspinning BH
at birth Kerr parameter (Lee,Brown,Wijers, ApJ 2002) Preexplosion orbital period (days)
at birth BH Spin Observation Line Profile Fabian Miniutti Doppler effect + Gravitational Redshifts Indication of BH spin
at birth Innermost stable circular orbit Fabian Miniutti Schwarzschild BH Kerr BH Line Intensity
at birth • Rapidly spinning black holes at birth Shafee et al. (2006) 4U 1543-47GRO J1655-40 Sources for GRB & Hypernovae at birth Preexplosion orbital period (days)
after BH • Kerr parameter McClintock et al. (2006) GRS 1915+105P=33 daysa* > 0.98 4U 1543-47GRO J1655-40 Preexplosion orbital period (days)
after BH Q) How to form BHs in 10-15 Msun ? • problem 1:It’s hard to form BH with masses > 10 Msun from stellar evolution. • problem 2:The current separation is too large. • Problem 3:Observed Kerr parameter is too big. • easiest solution: Accrete extra mass after BH formation [ApJ (2002)]
after BH Shrink Evolved Companion Expand MS companion I: Hubble TimeII: Main SequenceIII: Oveflow at t=0 AML: Angular Mom Loss Nu: Nuclear Burning
after BH Allowed region due to Case C Current Observation
after BH 15 Msun ? OK 10 Msun Q) How to Evolve ?
after BH ?
after BH Conservative Mass Transfer V4641 Sgr Data: 33.5 days 2.817 days GRS 1915+105 Consistent within error range
after BH Spin-up due to accretion [Lee et al., ApJ (2002)] GRS 1915+105a* > 0.98 McClintock et al. (2006) Low-spin black holes at birth No GRB/Hypernovae
after BH • Kerr parameter GRS 1915+105P=33 daysa* > 0.98 4U 1543-47GRO J1655-40 Preexplosion orbital period (days)
at birth Pre-Explosion Properties V4641 & 1915
at birth Reconstructed BH Binaries at Birth (before accretion) GRBs/Hypernovae Rapidly spinning BHs
at birth Available BH Spin Energies ? H.K. Lee (Blandford-Znajek)