1/47 Recent Progress in Gamma-ray Bursts: S. R. Kulkarni California Institute of Technology Image Credit: NASA E/PO, Sonoma State University, Aurore Simonnet

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3/47 Long & Short

4/47 The Gang and collaborators 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 G. Kosugi, NAOJ W. Krzeminski, Carnegie S. R. Kulkarni, Caltech P. Kumar, U. Texas D. C. Leonard, Caltech B. L. Lee, U. Toronto A. MacFadyen, IAS P. J. McCarthy, 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 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

5/47 Collaborators 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 G. Kosugi, NAOJ W. Krzeminski, Carnegie S. R. Kulkarni, Caltech P. Kumar, U. Texas D. C. Leonard, Caltech B. L. Lee, U. Toronto A. MacFadyen, IAS P. J. McCarthy, 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 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

6/47 Long Duration Bursts: Collapsar Model: Woosley, Heger, MacFadyen Kulkarni et al. Bloom et al. Frail et al. Berger et al. Soderberg etal

7/47 SN 1998bw/GRB Galama et al. 1998, Kulkarni et al E  ~10 48 erg (isotropic)

8/47 Collapsar: The Movie A Hollywood-Bollywood Production From Bogus Enterprise, A Division of General Propaganda

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10/47 With physics and lots of hardwork (MacFadyen)

11/47 A New Family of Cosmic Explosions : Soderberg

12/47 Keck Laser Guide Star AO

13/47 Progenitors of Ibc SNe: A Hot Result

14/47 Palomar 60-inch: A second life

15/47 Exploitation of GRBs has already begun Reichart et al Berger et al. GRB : z=6.2 Observations at 3 hours (P60, optical; SOAR, NIR)

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17/47 Two classes of GRBs Short - Hard Long - Soft

18/47 Summarizing Four Papers 1.Fox et al. “The afterglow of GRB and the nature of the short-hard γ-ray bursts”, Nature, October 6, Berger et al. “A merger origin for short γ-ray bursts inferred from the afterglow and host galaxy of GRB ”, Nature, November, Kulkarni “Modeling Macronovae” 4.Kulkarni et al. “Constraints on supernova-like emission associated with the short-hard gamma-ray burst b

19/47 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.

20/47 GRB B: Swift Detection 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? Gehrels et al T 90 =40 ms

21/47 Bloom et al NSC J z=0.225

22/47 Kulkarni et al GRB B: Keck/Subaru Error radius = 9.3 arcsec

23/47 HST Imaging: No Supernova Kulkarni et al Error radius = 9.3 arcsec 4 HST Epochs May 14 to June sources in XRT error circle Giant elliptical Bloom et al L=1.5L * SFR<0.1 M  yr -1

24/47 Kulkarni et al Panchromatic Studies

25/47 GRB : HETE Detection A Hard spike, 84 keV A Soft (PL) bump (alpha=-2) Roughly equal energy in each component Villasenor et al T 90 =70 ms

26/47 GRB : Accurate Localization Fox et al SXC c GRB

27/47 HST imaging & search for supernova explosion Fox et al. 2005

28/47 GRB : 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= > -2.8) –“jet” break at T+10 d –SN limits M R >-12 mag Radio –violate simple AG model Fox et al. 2005; Hjorth et al. 2005

29/47 GRB : Swift Detection Brightest Swift SHB Hard spike/soft bump X-ray, optical and radio afterglow detected Barthelmy al T 90 =40 ms keV keV T 90 =3 s 250 ms 100 s

30/47 Barthelmy al. 2005

31/47 Berger et al GRB : Swift

32/47 Kulkarn i & C ameron Red elliptical z=0.258 L=1.6 L * SFR<0.03 M  yr -1

33/47 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 to erg –Evidence for ``jets’’ Is there an associated supernova explosion? –Supernova, if any, are faint (M v > -13) What are they? –Both elliptical and star-forming host galaxies

34/47 Comparison to Long Duratrion Gamma-ray Bursts

35/47 Empirical Connection to Ia Supernovae Nakar & Gal-Yam

36/47 Binary Coalescence 1 Collapsar Magnetar Energy Density Host Offset No SNe The Score Card

37/47 Holy smokes, he is dead?!! Ph: Glendinning

38/47 Coalescence of Neutron Stars (Shibata)

39/47 Black Hole-Neutron Star (Rupert, Janka)

40/47 Macronova Is there a sub-relativistic explosion accompanying short hard bursts? Li & Paczynski 1998 If so, (observationally) > Nova < Supernova => “Mini-supernova” or “Macronova” Kulkarni

41/47 Macronova Model Parameters: M ejecta & v=  c Composition –Free Neutrons –Radioactive Nickel –Neutron Rich Material (non-radioactive) Injection of energy essential for macronova to shine and be detectable

42/47 Nickel Decay

43/47 r-process and s-process elements

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45/47 Comparison to Data (GRB b)  =0.5  =0.05

46/47 The Macronova as a Reprocessor

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50/47 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.

51/47 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.

52/47 The Macronova as a reprocessor Long lived central soure (e.g. magnetar) Long lived accretion disk There are already indications of tremendous late time activity.

53/47 SHBs Observational Milestones 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 –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 –discovery of first radio afterglow –unambiguous identification of red elliptical host galaxy (z=0.257)

54/47 Coalescence --> Black Hole (Shibata)

55/47 Gal Yam

56/47 Possible SHB Progenitors Magnetar –Highly magnetized young neutron star ( 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

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58/47 Taken from K.Thorne NSF Review talk Widely expected based on burst brightness distribution – =0.39+/0.02 –luminosity similar to long bursts but duration 100x 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 Guetta & Piran (2005) SF + delay

59/47 GRB/Host Offset Distributions Offsets are notoriously difficult to calculate. –Binary synthesis models –Galactic population of binaries Depends on… –Merger times ( Gyrs) –Proper motions ( km/s) –Host galaxy potential –Binary evolution theory Future offsets can help constrain all of above Fryer, Woosley & Hartmann 1999 Collapsar NS/NS

60/47 Merging Neutron Stars and LIGO-II Taken from K.Thorne NSF Review talk

61/47 NASA “films” a NS/NS Merger Photo Credit: NASA/Dana Berry

62/47 Use this Slide in Italy. 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 (α 1 =-1.3 and α 2 =-2.8) –“jet” break at T+10 d –SNe limits M R >-12 mag Radio –violate simple AG model Fox et al. 2005

63/47 GRB : Optical Afterglow Price et al and Hjorth et al 2005 T+1.42 d T+2.39 d ΔTΔT Decays as t m Danish Telescope, La Silla

64/47 GRB : Gemini Spectra Prochaska et al. ; Berger et al z=0.257

65/47 Short Bursts and Gravitational Waves

66/47 Fryer, Woosley & Hartmann 1999 Ruffert & Janka 2001

67/47 Palomar 60-inch: Now a robotic telescope