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http://hdl.handle.net/2381/18795
Title: | The Swift gamma-ray burst GRB 050422 |
Authors: | Beardmore, A. P. Page, K. L. O'Brien, P. T. Osborne, J. P. Goad, M. R. Godet, O. Wells, A. A. Kobayashi, S. Zhang, B. Burrows, D. N. Capalbi, M. Hill, J. E. Marshall, F. La Parola V. |
First Published: | 1-Feb-2007 |
Publisher: | Royal Astronomical Society (RAS) |
Citation: | Monthly Notices of the Royal Astronomical Society, 2007, 374 (4), pp. 1473-1478 |
Abstract: | We describe observations of GRB 050422, a Swift-discovered gamma-ray burst. The prompt gamma-ray emission had a T90 duration of 59 s and was multipeaked, with the main peak occurring at T+ 53 s. Swift was able to follow the X-ray afterglow within 100 s of the burst trigger. The X-ray light curve, which shows a steep early decline, can be described by a broken power law with an initial decay slope of α1∼ 5.0, a break time tb∼ 270 s and a post-break decay slope of α2∼ 0.9, when the zero time of the X-ray emission is taken to be the burst trigger time. However, if the zero time is shifted to coincide with the onset of main peak in the gamma-ray light curve then the initial decay slope is shallower with α1∼ 3.2. The initial gamma-ray spectrum can be modelled by a power law with a spectral index of βB= 0.50 ± 0.19. However, the early time X-ray spectrum is significantly steeper than this and requires a spectral index of βX= 2.33+0.58−0.55. In comparison with other Swift bursts, GRB 050422 was unusually X-ray faint, had a soft X-ray spectrum, and had an unusually steep early X-ray decline. Even so, its behaviour can be accommodated by standard models. The combined BAT/XRT light curve indicates that the initial, steeply declining, X-ray emission is related to the tail of the prompt gamma-ray emission. The shallower decay seen after the break is consistent with the standard afterglow model. |
DOI Link: | 10.1111/j.1365-2966.2006.11249.x |
ISSN: | 0035-8711 |
eISSN: | 1365-2966 |
Links: | http://hdl.handle.net/2381/18795 http://mnras.oxfordjournals.org/content/374/4/1473 |
Version: | Publisher Version |
Status: | Peer-reviewed |
Type: | Journal Article |
Rights: | This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2006 the authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. Deposited with reference to the publisher’s archiving policy available on the SHERPA/RoMEO website. |
Appears in Collections: | Published Articles, Dept. of Physics and Astronomy |
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File | Description | Size | Format | |
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MNRAS-2007-Beardmore-1473-8.pdf | Published (publisher PDF) | 216.58 kB | Adobe PDF | View/Open |
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