Recent Progress in Gammaray Bursts S R Kulkarni

Recent Progress in Gamma-ray Bursts: S. R. Kulkarni California Institute of Technology 1 Image Credit: NASA E/PO, Sonoma State University, Aurore Simonnet

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Long & Short 3

The Gang and collaborators K. Aoki, NAOJ E. Berger, Carnegie P. B. Cameron, Caltech R. A. Chevalier, U. Virginia S. B. Cenko, Caltech L. L. Cowie, U. Hawaii A. Dey, NOAO S. Evans, LANL D. B. Fox, Penn S. /Caltech D. A. Frail, NRAO H. Furusawa, TIT A. Gal-Yam, Caltech F. A. Harrison, Caltech K. C. Hurley, UC Berkeley M. M. Kasliwal, Caltech N. Kawai, TIT G. Kosugi, NAOJ W. Krzeminski, Carnegie S. R. Kulkarni, Caltech P. Kumar, U. Texas D. C. Leonard, Caltech B. L. Lee, U. Toronto A. Mac. Fadyen, IAS P. J. Mc. Carthy, Carnegie D. -S. Moon, Caltech D. C. Murphy, Carnegie E. Nakar, Caltech H. S. Park, LLNL B. Penprase, Pomona C. S. E. Persson, Carnegie B. A. Peterson, ANU M. M. Phillips, Carnegie T. Piran, Hebrew U. P. A. Price, U. Hawaii J. Rich, ANU M. Rauch, Carnegie K. Roth, Gemini Obs M. Roth, Carnegie D. J. Sand, Caltech B. P. Schmidt, ANU S. Shectman, Carnegie A. M. Soderberg, Caltech M. Takada, Tohuku U. T. Totani, Kyoto U. W. T. Vestrand, LANL D. Watson, U. Copenhagen R. White, LANL P. Wozniak, LANL J. Wren, LANL 4

Collaborators K. Aoki, NAOJ E. Berger, Carnegie P. B. Cameron, Caltech R. A. Chevalier, U. Virginia S. B. Cenko, Caltech L. L. Cowie, U. Hawaii A. Dey, NOAO S. Evans, LANL D. B. Fox, Penn S. /Caltech D. A. Frail, NRAO H. Furusawa, TIT A. Gal-Yam, Caltech F. A. Harrison, Caltech K. C. Hurley, UC Berkeley M. M. Kasliwal, Caltech N. Kawai, TIT G. Kosugi, NAOJ W. Krzeminski, Carnegie S. R. Kulkarni, Caltech P. Kumar, U. Texas D. C. Leonard, Caltech B. L. Lee, U. Toronto A. Mac. Fadyen, IAS P. J. Mc. Carthy, Carnegie D. -S. Moon, Caltech D. C. Murphy, Carnegie E. Nakar, Caltech H. S. Park, LLNL B. Penprase, Pomona C. S. E. Persson, Carnegie B. A. Peterson, ANU M. M. Phillips, Carnegie T. Piran, Hebrew U. P. A. Price, U. Hawaii J. Rich, ANU M. Rauch, Carnegie K. Roth, Gemini Obs M. Roth, Carnegie D. J. Sand, Caltech B. P. Schmidt, ANU S. Shectman, Carnegie A. M. Soderberg, Caltech M. Takada, Tohuku U. T. Totani, Kyoto U. W. T. Vestrand, LANL D. Watson, U. Copenhagen R. White, LANL P. Wozniak, LANL J. Wren, LANL 5

Long Duration Bursts: Kulkarni et al. Bloom et al. Frail et al. Berger et al. Soderberg etal 6 Collapsar Model: Woosley, Heger, Mac. Fadyen

SN 1998 bw/GRB 980425 E ~1048 erg (isotropic) Galama et al. 1998, Kulkarni et al. 1998 7

Collapsar: The Movie A Hollywood-Bollywood Production From Bogus Enterprise, A Division of General Propaganda 8

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With physics and lots of hardwork (Mac. Fadyen) 10

A New Family of Cosmic Explosions: Soderberg 11

Keck Laser Guide Star AO 12

Progenitors of Ibc SNe: A Hot Result 13

Palomar 60 -inch: A second life 14

Exploitation of GRBs has already begun GRB 050904: z=6. 2 Observations at 3 hours (P 60, optical; SOAR, NIR) Reichart et al. 2005 Berger et al. 15

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Two classes of GRBs Short - Hard Long - Soft 17

Summarizing Four Papers 1. Fox et al. “The afterglow of GRB 050709 and the nature of the short-hard γ-ray bursts”, Nature, October 6, 2005 2. Berger et al. “A merger origin for short γ-ray bursts inferred from the afterglow and host galaxy of GRB 050724”, Nature, November, 2005 3. Kulkarni “Modeling Macronovae” 4. Kulkarni et al. “Constraints on supernova-like emission associated with the short-hard gamma-ray burst 050509 b 18

Toward the SHB Progenitor: Redux • How far away are they? • How much energy do they release? – is the energy release isotropic or collimated? – are the central engines long or short-lived? – Is there associated non-relativistic ejecta? • What are the progenitors? – Clue (macro) = host galaxy + offset – Clue (micro) = circumburst environment The key to answering these questions has been the precise positions enabled by the discovery of long-lived afterglows. 19

Gehrels et al. 2005 GRB 050509 B: Swift Detection T 90=40 ms • BAT: very faint GRB • XRT: T+62 s detects 11 photons(!) • No optical, no radio. very faint limits – Low energy event and/or low density medium? • Giant elliptical galaxy in cluster. z=0. 22 Host? 20

NSC J 123610+285901 z=0. 225 Bloom et al. 2005 21

HST Imaging: No Supernova 48 sources in XRT error circle Error radius = 9. 3 arcsec 4 HST Epochs May 14 to June 10 Giant elliptical Bloom et al L=1. 5 L* Kulkarni et al. 2005 SFR<0. 1 M yr-1 23

GRB 050709: HETE Detection Villasenor et al. 2005 • A Hard spike, 84 ke. V • A Soft (PL) bump (alpha=-2) • Roughly equal energy in each component T 90=70 ms 25

GRB 050709: Accurate Localization GRB SXC c Fox et al. 2005 26

HST imaging & search for supernova explosion 27 Fox et al. 2005

GRB 050709: Panchromatic Studies • X-ray – source “flares” for initial 6 ks of 18 ks in second epoch • Long-lived central engine? – early and late flux do not fit • Optical – inconsistent with simple PL decay (slope=-1. 3 --> -2. 8) – “jet” break at T+10 d – SN limits MR>-12 mag • Radio – violate simple AG model Fox et al. 2005; Hjorth et al. 2005 28

GRB 050724: Swift Detection 15 -150 ke. V 250 ms Barthelmy al. 2005 T 90=3 s • Brightest Swift SHB • Hard spike/soft bump • X-ray, optical and radio afterglow detected T 90=40 ms 15 -25 ke. V 100 s 29

Barthelmy al. 2005 30

GRB 050724: Swift Berger et al. 2005 31

Red elliptical z=0. 258 L=1. 6 L* SFR<0. 03 M yr-1 Kulkarni & Cameron 32

Toward the SHB Progenitor • How far away are they? – At least some short bursts are z ~ 0. 2 • How much energy do they release? – About 1049 to 1050 erg – Evidence for ``jets’’ • Is there an associated supernova explosion? – Supernova, if any, are faint (Mv > -13) • What are they? – Both elliptical and star-forming host galaxies 33

Comparison to Long Duratrion Gamma-ray Bursts 34

Empirical Connection to Ia Supernovae Nakar & Gal-Yam 35

The Score Card Energy Density Host Offset No SNe Magnetar 0 1 0 0 1 1 1 0 0 0 1 1 Collapsar Binary Coalescence 1 36

Holy smokes, he is dead? !! 37 Ph: Glendinning

Coalescence of Neutron Stars (Shibata) 38

Black Hole-Neutron Star (Rupert, Janka) 39

Macronova • Is there a sub-relativistic explosion accompanying short hard bursts? Li & Paczynski 1998 • If so, (observationally) > Nova < Supernova => “Mini-supernova” or “Macronova” Kulkarni 40

Macronova Model • Parameters: Mejecta & v= c • Composition – Free Neutrons – Radioactive Nickel – Neutron Rich Material (non-radioactive) • Injection of energy essential for macronova to shine and be detectable 41

Nickel Decay 42

r-process and s-process elements 43

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Comparison to Data (GRB 050509 b) =0. 5 =0. 05 45

The Macronova as a Reprocessor 46

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Quasars: A Historical Analogy, II • Scintillation: Interplanetary Scintillation showed that quasars were compact • The Central Engine: After three decades we have a working model involving black holes • The Pesky Jets: Questions remain – FRI and FRII – What is the difference between radio quiet and radio loud AGN? • Unification: The desire to unify various classes of quasars drove much of quasar research. 50

Quasars: A Historical Analogy, I • Astonished & Impressed: The immense power and energy of quasars resulting from Schmidt’s discovery of redshift. • Amused and Educated: Relativistic effects such as super-luminal motion were anticipated by Rees. • Ruthless Exploitation: Ask not why quasars quase but simply use them as light beacons to study the IGM. 51

The Macronova as a reprocessor • Long lived central soure (e. g. magnetar) • Long lived accretion disk There already indications of tremendous late time activity. 52

SHBs Observational Milestones • 050509 B – rapid arcsecond (+/-9. 3”) localization of X-ray emission (AG? ) – tentative host is elliptical galaxy in merging cluster (z=0. 225) – macronova and SNe limits • 050709 – – – sub-arcsecond position of X-ray afterglow unambiguous identification of spiral host galaxy & redshift (z=0. 16) discovery of optical afterglow evidence that outflows are jet-like evidence that central engines remain active for days to weeks • 050724 – discovery of first radio afterglow – unambiguous identification of red elliptical host galaxy (z=0. 257) 53

Coalescence --> Black Hole (Shibata) 54

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Possible SHB Progenitors • Magnetar – – • Highly magnetized young neutron star (1014 -1015 G) Crustal breaking and magnetic reconnection = hyper-flares short (0. 2 s) hard pulse and long (300 s), soft pulse Dominant timescale is Alfven velocity in NS Collapsar – – • Massive star core collapses to black hole + short-lived accretion disk Nicely explains long-soft bursts Dominant timescale is set by jet propagation in CO core (20 s) Shorter timescales = collimated jet that wanders due to instabilities Binary Coalescence – – – Merging compact remnants (WD, NS, & BH) Hypercritical accretion onto a newly formed BH Dominant timescale is set by accretion disk viscosity 56

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Guetta & Piran (2005) SF + delay • Widely expected based on burst brightness distribution – <V/Vmax>=0. 39+/0. 02 – luminosity similar to long bursts but duration 100 x less – predicts faint AG • Future z distribution will constrain merger timescale • Tavnir et al (astro-ph) suggests 5 -25% SHB are at d<100 kpc • Good news for GW detectors like LIGO Taken from K. Thorne NSF Review talk 58

GRB/Host Offset Distributions • Offsets are notoriously difficult to calculate. Colla psar NS/N S – Binary synthesis models – Galactic population of binaries • Depends on… – – Merger times (0. 1 -100 Gyrs) Proper motions (50 -500 km/s) Host galaxy potential Binary evolution theory • Future offsets can help constrain all of above Fryer, Woosley & Hartmann 1999 59