University of Leicester
Browse
19785.web.pdf (107.83 kB)

The soft X-ray blast in the apparently sub-luminous GRB 031203

Download (107.83 kB)
journal contribution
posted on 2016-08-03, 12:21 authored by D. Watson, S. A. Vaughan, R. Willingale, J. Hjorth, S. Foley, J. P. U. Fynbo, P. Jakobsson, A. Levan, P. T. O'Brien, J. P. Osborne, K. Pedersen, J. N. Reeves, Jonathan A. Tedds, M. G. Watson
GRB031203 was a very low apparent luminosity gamma-ray burst (GRB). It was also the first GRB with a dust-scattered X-ray halo. The observation of the halo allowed us to infer the presence of a large soft X-ray fluence in the total burst output. It has, however, also been claimed that GRB031203 was intrinsically sub-energetic, representative of a class of spectrally hard, low-energy bursts quite different from other GRBs. Reanalysis of the available data confirms our original finding that GRB031203 had a very large soft X-ray component, the time of which can be constrained to within a few minutes after the burst, implying that while GRB031203 did indeed have a very low apparent luminosity, it was also very soft. Notions propagated in the literature regarding the uncertainties in the determination of the soft X-ray fluence from the halo data and on the available constraints from the hard X-ray data are addressed: the properties of the scattering dust along the line of sight (grain sizes, precise location and the geometry) are determined directly from the high quality X-ray data so that there is little uncertainty about the scatterer; constraints on the X-ray lightcurve from the Integral spacecraft at the time of the soft X-ray blast are not complete because of a slew in the spacecraft pointing shortly after the burst. Claims that GRB031203 was intrinsically under-energetic and that it represents a deviation from the luminosity-peak energy relation do not appear to be substantiated by the data, regardless of whether the soft X-ray component is declared part of the prompt emission or the afterglow. We conclude that the difference between the soft and hard X-ray spectra from XMM-Newton and Integral indicate that a second soft pulse probably occurred in this burst as has been observed in other GRBs, notably GRB050502B.

History

Citation

Astrophysical Journal, 636, pp. 967-970

Author affiliation

/Organisation/COLLEGE OF MEDICINE, BIOLOGICAL SCIENCES AND PSYCHOLOGY/School of Medicine/Department of Health Sciences

Version

  • VoR (Version of Record)

Published in

Astrophysical Journal

Publisher

IOP Publishing for American Astronomical Society

issn

0004-637X

eissn

1538-4357

Copyright date

2006

Available date

2016-08-03

Publisher version

http://iopscience.iop.org/article/10.1086/498089/meta;jsessionid=2D59AEEED9C2A17F212A5A76910B63DE.c4.iopscience.cld.iop.org

Notes

4 pages, 2 figures, emulateapj Accepted for publication in ApJ, scheduled 10 January 2006 issue

Language

en

Usage metrics

    University of Leicester Publications

    Categories

    Keywords

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC