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Implications for the origin of short gamma-ray bursts from their observed positions around their host galaxies

Church, Ross LU ; Levan, Andrew J.; Davies, Melvyn B LU and Tanvir, Nial (2011) In Monthly Notices of the Royal Astronomical Society 413(3). p.2004-2014
Abstract
We present the observed offsets of short-duration gamma-ray bursts (SGRBs) from their putative host galaxies and compare them with the expected distributions of merging compact object binaries, given the observed properties of the hosts. We find that for all but one burst in our sample the offsets are consistent with this model. For the case of bursts with massive elliptical host galaxies, the circular velocities of the hosts' haloes exceed the natal velocities of almost all our compact object binaries. Hence, the extents of the predicted offset distributions for elliptical galaxies are determined largely by their spatial extents. In contrast, for spiral hosts, the galactic rotation velocities are smaller than typical binary natal... (More)
We present the observed offsets of short-duration gamma-ray bursts (SGRBs) from their putative host galaxies and compare them with the expected distributions of merging compact object binaries, given the observed properties of the hosts. We find that for all but one burst in our sample the offsets are consistent with this model. For the case of bursts with massive elliptical host galaxies, the circular velocities of the hosts' haloes exceed the natal velocities of almost all our compact object binaries. Hence, the extents of the predicted offset distributions for elliptical galaxies are determined largely by their spatial extents. In contrast, for spiral hosts, the galactic rotation velocities are smaller than typical binary natal velocities and the predicted burst offset distributions are more extended than the galaxies. One SGRB, 060502B, apparently has a large radial offset that is inconsistent with an origin in a merging galactic compact binary. Although it is plausible that the host of GRB 060502B is misidentified, our results show that the large offset is compatible with a scenario where at least a few per cent of SGRBs are created by the merger of compact binaries that form dynamically in globular clusters. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
binaries: general, gamma-ray burst: general
in
Monthly Notices of the Royal Astronomical Society
volume
413
issue
3
pages
2004 - 2014
publisher
Wiley-Blackwell
external identifiers
  • wos:000290487700044
  • scopus:79955759632
ISSN
1365-2966
DOI
10.1111/j.1365-2966.2011.18277.x
language
English
LU publication?
yes
id
f114d60f-7f0c-4144-91c3-964e56a6d461 (old id 1986737)
date added to LUP
2011-06-29 10:55:49
date last changed
2017-11-05 03:01:00
@article{f114d60f-7f0c-4144-91c3-964e56a6d461,
  abstract     = {We present the observed offsets of short-duration gamma-ray bursts (SGRBs) from their putative host galaxies and compare them with the expected distributions of merging compact object binaries, given the observed properties of the hosts. We find that for all but one burst in our sample the offsets are consistent with this model. For the case of bursts with massive elliptical host galaxies, the circular velocities of the hosts' haloes exceed the natal velocities of almost all our compact object binaries. Hence, the extents of the predicted offset distributions for elliptical galaxies are determined largely by their spatial extents. In contrast, for spiral hosts, the galactic rotation velocities are smaller than typical binary natal velocities and the predicted burst offset distributions are more extended than the galaxies. One SGRB, 060502B, apparently has a large radial offset that is inconsistent with an origin in a merging galactic compact binary. Although it is plausible that the host of GRB 060502B is misidentified, our results show that the large offset is compatible with a scenario where at least a few per cent of SGRBs are created by the merger of compact binaries that form dynamically in globular clusters.},
  author       = {Church, Ross and Levan, Andrew J. and Davies, Melvyn B and Tanvir, Nial},
  issn         = {1365-2966},
  keyword      = {binaries: general,gamma-ray burst: general},
  language     = {eng},
  number       = {3},
  pages        = {2004--2014},
  publisher    = {Wiley-Blackwell},
  series       = {Monthly Notices of the Royal Astronomical Society},
  title        = {Implications for the origin of short gamma-ray bursts from their observed positions around their host galaxies},
  url          = {http://dx.doi.org/10.1111/j.1365-2966.2011.18277.x},
  volume       = {413},
  year         = {2011},
}