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Short Bursts. Daniel Perley Astro 250 9 November 2005. 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

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Short bursts

Short Bursts

Daniel Perley

Astro 250

9 November 2005


Short bursts

Classes of GRBsLong 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

Long Bursts

GRB Classes

GRBs have long been known to fall into two general categories:

l o n g b u r s t

45 s

count rate (ct/s)

time (seconds)

Daniel Perley

Short Bursts

9 November 2005


Short bursts

Classes of GRBs Long BurstsShort 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

Short Bursts

GRB Classes

GRBs have long been known to fall into two general categories:

0.8 s

short burst

count rate (ct/s)

time (seconds)

Daniel Perley

Short Bursts

9 November 2005


Short bursts

Classes of GRBs Long Bursts Short BurstsDurations 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

Burst Durations

GRB Classes

The separate populations are statsitcally robust, although intersecting.

N

10-2

10-1

1

10

100

1000

T90 (seconds)

Daniel Perley

Short Bursts

9 November 2005


Short bursts

Classes of GRBs Long Bursts Short BurstsDurations 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

Burst Durations

GRB Classes

The separate populations are statsitcally robust, although intersecting.

l o n g b u r s t s

N

short bursts

10-2

10-1

1

10

100

1000

T90 (seconds)

Daniel Perley

Short Bursts

9 November 2005


Short bursts

Classes of GRBs Long Bursts Short Bursts DurationsDuration 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

Duration/Hardness

GRB Classes

The two populations have different hardnesses:

short bursts

Hardness (S3/S2)

l o n g b u r s t s

T90 (seconds)

Daniel Perley

Short Bursts

9 November 2005


Short bursts

Classes of GRBs Long Bursts Short Bursts Durations Duration vs. HardnessDuration 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

Duration/Fluence

GRB Classes

Other intrinsic differences have also been noticed.

10-4

l o n g b u r s t s

10-5

Ftot (erg/cm2)

10-6

10-7

short bursts

10-8

10-2

1

10

100

1000

10-1

T90 (seconds)

Figure 1, Balasz et al. 2004

Daniel Perley

Short Bursts

9 November 2005


Short bursts

Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence

Short Bursts before SwiftLong 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

Long Burst Localization

Before Swift

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.

Daniel Perley

Short Bursts

9 November 2005


Short bursts

Classes of GRBs Long Bursts Short Bursts Durations Duration vs. Hardness Duration vs. Fluence

Short Bursts before Swift Long Burst LocalizationShort 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

Short Burst Localization

Before Swift

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.

5 '

Daniel Perley

Short Bursts

9 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

Afterglow Nondetections

1 = 000607 5.6 arcmin2

2 = 001025B 24.5 arcmin2

3 = 001204 6 arcmin2

4 = 010119 3.3 arcmin2

= long burst detected

= long burst limit

Before Swift

Before thist year, no short burst afterglow had been found in any IPN or burst detection error box.

Daniel Perley

Short Bursts

9 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 NondetectionsGalaxy 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

Galaxy Correlations

Before Swift

(Recent) study computes correlation function of BATSE short burst positions with nearby galaxies.

Result: correlation significant to 2σ

No correlation seen for long bursts.

Estimate of 5-25% of GRBs from <100 Mpc

Daniel Perley

Short Bursts

9 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

Burst Models

Burst Models

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)

Daniel Perley

Short Bursts

9 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 ModelsPrimordial 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

Primordial Black Holes

N

10-2

10-1

1

10

100

1000

T90 (seconds)

Burst Models

An early suggestion: GRBs may be the evaporation of black holes produced in the early universe.

Mass: 7 × 1014 g (mc2 = 5 × 1035 erg)

→ Distance: ~few parsecs

Burst duration: <50-200 ms

cannot explain most short bursts

Daniel Perley

Short Bursts

9 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 HolesMagnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary

Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary

Conclusions

Magnetar Giant Flare

Burst Models

Massive flare on the surface of highly magnetized neutron star.

Catastrophic magnetic field reorganization.

Some previous flares:

- 5 March 1979 event: 4 × 1044 ergs (SGR 0526-66, LMC) 0.2 s

- 27 August 1998 event: 8 × 1043 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?

Daniel Perley

Short Bursts

9 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 HolesMagnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary

Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary

Conclusions

Magnetar Giant Flare

Burst Models

- 5 March 1979 event: 4 × 1044 ergs (SGR 0526-66, LMC) 0.2 s

- 27 August 1998 event: 8 × 1043 ergs (SGR 1900+14) 0.2 s

- 27 December 2004 event 2 × 1046 ergs (SGR 1806-20) 0.5 s

Most energetic Galactic event since Tycho.

0.8 erg/cm2 over 0.5s

Sirius: 10-4 erg/cm2/sFull Moon: 1 erg/cm2/s

Daniel Perley

Short Bursts

9 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 HolesMagnetar Giant Flare NS-NS Merger NS-BH Merger Collapsar Summary

Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary

Conclusions

Magnetar Giant Flare

Burst Models

- 5 March 1979 event: 4 × 1044 ergs (SGR 0526-66, LMC) 0.2 s

- 27 August 1998 event: 8 × 1043 ergs (SGR 1900+14) 0.2 s

- 27 December 2004 event 2 × 1046 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: ~104 year lifetime (restricted to star-forming galaxies/regions)

Repetition possible over long time scales

Daniel Perley

Short Bursts

9 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 FlareNS-NS Merger NS-BH Merger Collapsar Summary

Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary

Conclusions

Neutron Star-Neutron Star Merger

Burst Models

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.

G M2 R

Gravitational binding energy:

~ 1053 erg

→ Mpc/Gpc distances

Timescale for collapse: <~1 second

Daniel Perley

Short Bursts

9 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 MergerNS-BH Merger Collapsar Summary

Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary

Conclusions

Neutron Star-Black Hole Merger

Burst Models

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.

Gravitational binding energy: MNSc2 ~ 1054 erg

→ Mpc/Gpc distances

Timescale for accretion: <~1 second

Supernovae can 'kick' binary out of Galaxy.

Daniel Perley

Short Bursts

9 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 FlareNS-NS MergerNS-BH Merger Collapsar Summary

Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary

Conclusions

Compact Object Mergers

Burst Models

Either type of merger:

Inspiral takes ~ 1 Gyr.

• Star formation may have ceased.

• System may have migrated from point of origin – supernova explosions cankick the binary well outside galacticinterior

Possibility of "mini-supernova" due to production of radioactive elements in ejected matter.

Daniel Perley

Short Bursts

9 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 MergerCollapsar Summary

Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary

Conclusions

Collapsar

Burst Models

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 Msun).

Relativistic jet penetrates stellar envelope

Energies ~ 1050 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)

Daniel Perley

Short Bursts

9 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 CollapsarSummary

Short Bursts since Swift GRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary

Conclusions

Model Summary

Burst Models

Daniel Perley

Short Bursts

9 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 SwiftGRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary

Conclusions

GRB 050509B

The Swift Era

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.

T90 = 0.040

S = 1 × 10-10

E = 3 × 1048

Large ellipticalz = 0.2248

XRT

all units CGS

blue

Daniel Perley

Short Bursts

9 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 SwiftGRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary

Conclusions

GRB 050509B

The Swift Era

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)

T90 = 0.040

S = 1 × 10-8

E = 3 × 1048

Large ellipticalz = 0.2248

XRT

40 kpc

blue

Daniel Perley

Short Bursts

9 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 SwiftGRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary

Conclusions

GRB 050509B

The Swift Era

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)

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.

T90 = 0.040

S = 1 × 10-8

E = 3 × 1048

Daniel Perley

Short Bursts

9 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 SwiftGRB050509B GRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary

Conclusions

GRB 050509B

The Swift Era

No counterpart seen at other wavelengths.

Cannot be a supernova (if in cluster).

No mini-supernova observed.

T90 = 0.040

S = 1 × 10-8

E = 3 × 1048

SNIapeak

Daniel Perley

Short Bursts

9 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 GRB050509BGRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary

Conclusions

GRB 050709

The Swift Era

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.

T90 = 0.070

S = 3 × 10-7

E = 2 × 1049

Star-forming irregularz = 0.160

XRT

3.8 kpc

HST Transient

Daniel Perley

Short Bursts

9 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 GRB050509BGRB050709 GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary

Conclusions

GRB 050709

The Swift Era

Optical light curve: power-law decay with jet break (like long burst – no supernova bump)

Radio

T90 = 0.070

S = 3 × 10-7

E = 2 × 1049

Optical

X-ray

Daniel Perley

Short Bursts

9 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 GRB050709GRB050724 GRB050813 GRB050906 GRB050925 GRB051103 GRB051105A Summary

Conclusions

GRB 050724

The Swift Era

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.

T90 = 3

S = 6 × 10-7

E = 1 × 1050

Early-typez = 0.258

2.6 kpc

XRT

Transient

Daniel Perley

Short Bursts

9 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

GRB 050813

The Swift Era

X-ray afterglow, but no optical/radio transient.

Inside a cluster - numerous possible hosts.

Ellipticalz = 0.722

XRT

T90 = 0.6

S = 6 × 10-7

E = 1 × 1050

Ellipticalz = 0.719

Ellipticalz = 0.73

Daniel Perley

Short Bursts

9 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 GRB050813GRB050906 GRB050925 GRB051103 GRB051105A Summary

Conclusions

GRB 050906

The Swift Era

No X-ray afterglow detected.

BAT position consistent with IC 326.

p ~ 0.1%

BAT

IC 326 z = 0.0308

T90 = 3

S = 6 × 10-8

E = 1 × 1047at 133 Mpc

IC 327

Daniel Perley

Short Bursts

9 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 GRB050906GRB050925 GRB051103 GRB051105A Summary

Conclusions

GRB 050925

The Swift Era

Soft, thermal spectrum.

Galactic latitude: b = - 0.1°

Strong radio source – no optical or X-ray detections.

SGR flare ('new' SGR)

T90 = 0.13

S = 8 × 10-8

E = 1 × 1040at 20 kpc

Daniel Perley

Short Bursts

9 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 GRB050925GRB051103 GRB051105A Summary

Conclusions

GRB 051103

The Swift Era

IPN detection of bright short GRB. Consistent with outer regions of M81.

M 82Irr z = 0

p ~ 0.5%

M 81Sb z = 0

T90 = 0.17

S = 2 × 10-5

E = 5 × 1046at 4 Mpc (M81)~ 1051at 500 Mpc

Daniel Perley

Short Bursts

9 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 GRB051103GRB051105A Summary

Conclusions

GRB 051105A

The Swift Era

No X-ray afterglow detected.

BAT

T90 = 0.13

S = 2 × 10-8

E = ?

Daniel Perley

Short Bursts

9 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 GRB051105ASummary

Conclusions

Recent Short Bursts

The Swift Era

energy (erg)

Daniel Perley

Short Bursts

9 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

Conclusions

The Swift Era

  • 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.

Daniel Perley

Short Bursts

9 November 2005