1. Short Bursts Daniel Perley Astro 250 9 November 2005

2. Title Subject Daniel Perley9 November 2005 Short Bursts Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions PBHflaremergercollapsar 10 36 10 46 >10 50 >10 50 pcMpcGpcGpc too shortOKOKtoo long? invisibleyoung NSold NSyoung star nearbygalactic star-forming galaxiesoutskirtsregions repeats?possibleIb/c supernova mini-SN

3. Long Bursts GRB Classes Daniel Perley9 November 2005 Short Bursts GRBs have long been known to fall into two general categories: time (seconds) count rate (ct/s) 45 s l o n g b u r s t Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

4. Short Bursts GRB Classes Daniel Perley9 November 2005 time (seconds) count rate (ct/s) short burst 0.8 s GRBs have long been known to fall into two general categories: Short Bursts Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

5. Burst Durations GRB Classes Daniel Perley9 November 2005 T 90 (seconds) N The separate populations are statsitcally robust, although intersecting. 10 -1 10 -2 1101001000 Short Bursts Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

6. Burst Durations GRB Classes Daniel Perley9 November 2005 T 90 (seconds) N 10 -1 10 -2 1101001000 The separate populations are statsitcally robust, although intersecting. short bursts l o n g b u r s t s Short Bursts Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

7. Duration/Hardness GRB Classes Daniel Perley9 November 2005 T 90 (seconds) The two populations have different hardnesses: Hardness (S 3 /S 2 ) short bursts l o n g b u r s t s Short Bursts Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

8. Duration/Fluence GRB Classes Daniel Perley9 November 2005 Other intrinsic differences have also been noticed. T 90 (seconds) 10 -1 10 -2 1101001000 F tot (erg/cm 2 ) 10 -8 10 -7 10 -6 10 -5 10 -4 Figure 1, Balasz et al. 2004 l o n g b u r s t s short bursts Short Bursts Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

9. Long Burst Localization Daniel Perley9 November 2005 First GRB (long burst) localized and first host identified in 1997. Many have followed since then. All long GRBs located in star-forming galaxies All long GRBs located in regions with massive stars Coincident type Ic supernova observed in one case → Long bursts are associated with supernovae. However, short GRBs long eluded localization, and no similar conclusions could be made. Short Bursts Before Swift Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

10. Short Burst Localization Daniel Perley9 November 2005 The intrinsically short duration of a short burst makes determining the position of the prompt gamma emission even more difficult than usual. "Best" localizations (5-50 square arcmin) generally from Interplanetary Network. Short Bursts 5 ' Before Swift Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

11. Afterglow Nondetections Before Swift Daniel Perley9 November 2005 Before thist year, no short burst afterglow had been found in any IPN or burst detection error box. Short Bursts 1 = 000607 5.6 arcmin 2 2 = 001025B 24.5 arcmin 2 3 = 001204 6 arcmin 2 4 = 010119 3.3 arcmin 2 = long burst detected = long burst limit Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

12. Galaxy Correlations Before Swift Daniel Perley9 November 2005 (Recent) study computes correlation function of BATSE short burst positions with nearby galaxies. Short Bursts Result: correlation significant to 2σ No correlation seen for long bursts. Estimate of 5-25% of GRBs from <100 Mpc Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

13. Burst Models Daniel Perley9 November 2005 A large number of models had been proposed – mostly of the same which had been previously proposed for GRBs in general. Black hole evaporation SGR (magnetar) giant flares Neutron star – neutron star mergers Neutron star – black hole mergers Collapsar Neutron star collapse (supranova) Short Bursts Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

14. Primordial Black Holes Burst Models Daniel Perley9 November 2005 An early suggestion: GRBs may be the evaporation of black holes produced in the early universe. T 90 (seconds) N 10 -1 10 -2 1101001000 Mass: 7 × 10 14 g (mc 2 = 5 × 10 35 erg) → Distance: ~few parsecs Burst duration: <50-200 ms cannot explain most short bursts Short Bursts Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

15. Magnetar Giant Flare Burst Models Daniel Perley9 November 2005 Massive flare on the surface of highly magnetized neutron star. Catastrophic magnetic field reorganization. Some previous flares: - 5 March 1979 event: 4 × 10 44 ergs (SGR 0526-66, LMC) 0.2 s - 27 August 1998 event: 8 × 10 43 ergs (SGR 1900+14) 0.2 s Duration and hardness consistent with short GRBs. Distance for GRB: 4 Mpc (Virgo cluster: 20 Mpc) But could there be much larger flares? Short Bursts Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

16. Magnetar Giant Flare Burst Models Daniel Perley9 November 2005 - 5 March 1979 event: 4 × 10 44 ergs (SGR 0526-66, LMC) 0.2 s - 27 August 1998 event: 8 × 10 43 ergs (SGR 1900+14) 0.2 s - 27 December 2004 event 2 × 10 46 ergs (SGR 1806-20) 0.5 s 0.8 erg/cm 2 over 0.5s Most energetic Galactic event since Tycho. Sirius: 10 -4 erg/cm 2 /s Full Moon: 1 erg/cm 2 /s Short Bursts Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

17. Magnetar Giant Flare Burst Models Daniel Perley9 November 2005 - 5 March 1979 event: 4 × 10 44 ergs (SGR 0526-66, LMC) 0.2 s - 27 August 1998 event: 8 × 10 43 ergs (SGR 1900+14) 0.2 s - 27 December 2004 event 2 × 10 46 ergs (SGR 1806-20) 0.5 s Duration and hardness consistent with short GRBs. (long ringing 'tail' would not be detectable at great distance) Distance for GRB: 30 Mpc (Virgo cluster: 20 Mpc) Magnetars all young: ~10 4 year lifetime (restricted to star-forming galaxies/regions) Repetition possible over long time scales Short Bursts Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

18. Neutron Star-Neutron Star Merger Burst Models Daniel Perley9 November 2005 Gravitational binding energy: ~ 10 53 erg → Mpc/Gpc distances Timescale for collapse: <~1 second Closely orbiting neutron stars (d ~< solar radius) lose energy from gravitational radiation. Systems known to exist (binary pulsars) Must eventually merge. Post-merger object quickly collapses to black hole Very high angular momentum of system : accretion disk forms; falls onto black hole. Short Bursts G M 2 R Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

19. Neutron Star-Black Hole Merger Burst Models Daniel Perley9 November 2005 Gravitational binding energy: M NS c 2 ~ 10 54 erg → Mpc/Gpc distances Timescale for accretion: <~1 second Closely orbiting neutron star / black hole pair also loses energy to gravitational radiation and merges. Neutron star is tidally disrupted into accretion disk; falls onto black hole. Short Bursts Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions Supernovae can 'kick' binary out of Galaxy.

20. Compact Object Mergers Burst Models Daniel Perley9 November 2005 Either type of merger: Inspiral takes ~ 1 Gyr. Star formation may have ceased. System may have migrated from point of origin – supernova explosions can kick the binary well outside galactic interior Possibility of "mini-supernova" due to production of radioactive elements in ejected matter. Short Bursts Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

21. Collapsar Burst Models Daniel Perley9 November 2005 Collapsar (hypernova) model highly successful in describing long bursts. Collapse of iron core of highly massive star to black hole + accretion of material (0.1-5 M sun ). Relativistic jet penetrates stellar envelope Energies ~ 10 50 erg : cosmological distances Fallback time for stellar core: ~few seconds too slow for short GRBs. Significant uncertanties in calculation; Breakout flash could be shorter? Massive stars short-lived: would be bound to star-forming regions (like long GRBs) Short Bursts Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

22. Model Summary Burst Models Daniel Perley9 November 2005 PBHgiant flaremergercollapsar Energy (erg) 10 36 10 46 ~10 50 >10 50 Distance scale pcMpcGpc Timescale too short OK too long? Progenitor mini-BHyoung NSold NS binary short-lived star Environment Galaxystar-forming galaxies in/near all types of galaxies star-forming galaxies Signatures possibility of repeat possible mini-SN type Ib/Ic supernova Short Bursts Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

23. GRB 050509B The Swift Era Daniel Perley9 November 2005 Short Bursts First Swift short burst. First X-ray afterglow: XRT provided 2.8' localization This position is very close to large elliptical at center of low-z cluster. XRT Large elliptical z = 0.2248 blue T 90 = 0.040 S = 1 × 10 -10 E = 3 × 10 48 Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions all units CGS

24. GRB 050509B The Swift Era Daniel Perley9 November 2005 Short Bursts Is the burst associated with the elliptical? Chance alignment probability very small. inside galaxy cluster: 3% within 45" of center: 0.07% (no long GRB ever seen in a cluster) XRT Large elliptical z = 0.2248 blue 40 kpc T 90 = 0.040 S = 1 × 10 -8 E = 3 × 10 48 Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

25. GRB 050509B The Swift Era Daniel Perley9 November 2005 Short Bursts Is the burst associated with the elliptical? Chance alignment probability very small. inside galaxy cluster: 3% within 45" of center: 0.07% (no long GRB ever seen in a cluster) T 90 = 0.040 S = 1 × 10 -8 E = 3 × 10 48 Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions Additional arguments: Extremely short duration even for short GRBs – putting at high redshift (z~2) requires unrealistically short intrinsic duration. Energetics of putting at high-z similarly difficult for very short durations.

26. GRB 050509B The Swift Era Daniel Perley9 November 2005 Short Bursts No counterpart seen at other wavelengths. Cannot be a supernova (if in cluster). No mini-supernova observed. T 90 = 0.040 S = 1 × 10 -8 E = 3 × 10 48 Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions SNIa peak

27. GRB 050709 The Swift Era Daniel Perley9 November 2005 Short Bursts HETE-II short burst. X-ray afterglow seen. Unambiguously in low-z galaxy. Optical transient (first ever for short GRB) detected coincident with X-ray position. XRT HST Transient Star-forming irregular z = 0.160 3.8 kpc T 90 = 0.070 S = 3 × 10 -7 E = 2 × 10 49 Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

28. GRB 050709 The Swift Era Daniel Perley9 November 2005 Short Bursts Optical light curve: power-law decay with jet break (like long burst – no supernova bump) T 90 = 0.070 S = 3 × 10 -7 E = 2 × 10 49 Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions X-ray Optical Radio

29. GRB 050724 The Swift Era Daniel Perley9 November 2005 Short Bursts Optical and radio (first for short GRB) transients seen. Unambiguously associated with non star-forming galaxy (within last Gyr) at low-z. Not in a cluster. Transient Early-type z = 0.258 XRT 2.6 kpc T 90 = 3 S = 6 × 10 -7 E = 1 × 10 50 Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

30. GRB 050813 The Swift Era Daniel Perley9 November 2005 Short Bursts X-ray afterglow, but no optical/radio transient. Inside a cluster - numerous possible hosts. XRT Elliptical z = 0.719 Elliptical z = 0.73 Elliptical z = 0.722 T 90 = 0.6 S = 6 × 10 -7 E = 1 × 10 50 Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

31. GRB 050906 The Swift Era Daniel Perley9 November 2005 Short Bursts No X-ray afterglow detected. BAT position consistent with IC 326. BATIC 326 z = 0.0308 IC 327 p ~ 0.1% T 90 = 3 S = 6 × 10 -8 E = 1 × 10 47 at 133 Mpc Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

32. GRB 050925 The Swift Era Daniel Perley9 November 2005 Short Bursts Soft, thermal spectrum. Galactic latitude: b = - 0.1° Strong radio source – no optical or X-ray detections. SGR flare ('new' SGR) T 90 = 0.13 S = 8 × 10 -8 E = 1 × 10 40 at 20 kpc Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

33. GRB 051103 The Swift Era Daniel Perley9 November 2005 Short Bursts IPN detection of bright short GRB. Consistent with outer regions of M81. M 81 Sb z = 0 M 82 Irr z = 0 p ~ 0.5% T 90 = 0.17 S = 2 × 10 -5 E = 5 × 10 46 at 4 Mpc (M81) ~ 10 51 at 500 Mpc Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

34. GRB 051105A The Swift Era Daniel Perley9 November 2005 Short Bursts No X-ray afterglow detected. BAT T 90 = 0.13 S = 2 × 10 -8 E = ? Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

35. Recent Short Bursts The Swift Era Daniel Perley9 November 2005 Short Bursts redshifthost trans most likely origin 050509B0.2248E (cl)3 × 10 48 XNS-NS/BH merger 0507090.160Irr2 × 10 49 XONS-NS/BH merger 0507240.258early1 × 10 50 XORNS-NS/BH merger 0508130.72E (cl)2 × 10 50 XNS-NS/BH merger 0509060.031?S1 × 10 47 giant flare? 050925Galaxy ~ 10 40 large SGR flare 0511030?Sb?5 × 10 46 giant flare? 051105A?? energy (erg) Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions

36. The Swift Era Daniel Perley9 November 2005 Short Bursts Most short bursts are due to compact object mergers. Short bursts are beamed. Some short bursts may be due to magnetar giant flares in other galaxies, but a definitive example is still lacking. Short bursts occur more frequently per volume than long bursts (or are beamed less), but are intrinsically fainter. Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence Short Bursts before Swift Long Burst Localization Short Burst Localization Afterglow Nondetections Galaxy Correlations Short Burst Models Primordial Black Holes Magnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary Conclusions