Implications for the origin of short gamma-ray bursts from their observed positions around their host galaxies
Church, Ross P., Levan, A. J., Davies, Melvyn B. and Tanvir, Nial. (2011) Implications for the origin of short gamma-ray bursts from their observed positions around their host galaxies. Monthly Notices of the Royal Astronomical Society, Vol.413 (No.3). pp. 2004-2014. ISSN 0035-8711Full text not available from this repository.
Official URL: http://dx.doi.org/10.1111/j.1365-2966.2011.18277.x
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.
|Item Type:||Journal Article|
|Subjects:||Q Science > QB Astronomy|
|Divisions:||Faculty of Science > Physics|
|Journal or Publication Title:||Monthly Notices of the Royal Astronomical Society|
|Official Date:||May 2011|
|Page Range:||pp. 2004-2014|
|Access rights to Published version:||Restricted or Subscription Access|
|Funder:||Wenner-Gren Foundation , Swedish Research Council , Royal Physiographic Society of Lund|
|Grant number:||2008-4089 (Swedish Research Council)|
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