0610899v2.pdf (447.61 kB)
Download file

Gamma-ray burst afterglows as probes of environment and blast wave physics. I. Absorption by host-galaxy gas and dust

Download (447.61 kB)
journal contribution
posted on 19.05.2020, 13:48 by RLC Starling, RAMJ Wijers, K Wiersema, E Rol, PA Curran, C Kouveliotou, AJ Van der Horst, MHM Heemskerk
We use a new approach to obtain limits on the absorbing columns toward an initial sample of 10 long gamma-ray bursts observed with BeppoSAX and selected on the basis of their good optical and near-infrared (NIR) coverage, from simultaneous fits to NIR, optical, and X-ray afterglow data, in count space and including the effects of metallicity. In no cases is a Milky Way-like (MW) extinction preferred when testing MW, LMC, and SMC extinction laws. The 2175 Å bump would in principle be detectable in all these afterglows, but is not present in the data. An SMC-like gas-to-dust ratio or lower value can be ruled out for four of the hosts analyzed here (assuming SMC metallicity and extinction law), while the remainder of the sample have too large an error to discriminate. We provide a more accurate estimate of the line-of-sight extinction and improve on the uncertainties for the majority of the extinction measurements made in previous studies of this sample. We discuss this method for determining extinction values in comparison with the most commonly employed existing methods.

Funding

This research has made use of SAXDAS linearized and cleaned event files produced at the BeppoSAX Science Data Center. The authors acknowledge benefits from collaboration within the Research Training Network ‘‘Gamma-Ray Bursts: An Enigma and a Tool,’’ funded by the EU under contract HPRN-CT-2002-00294. R. L. C. S. and E. R. acknowledge funding from the Particle Physics and Astronomy Research Council (PPARC).

History

Citation

ASTROPHYSICAL JOURNAL, 2007, 661 (2), pp. 787-800 (14)

Author affiliation

/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Physics and Astronomy

Version

VoR (Version of Record)

Published in

ASTROPHYSICAL JOURNAL

Volume

661

Issue

2

Pagination

787-800 (14)

Publisher

American Astronomical Society, IOP Publishing

issn

0004-637X

eissn

1538-4357

Acceptance date

15/12/2006

Copyright date

2007

Available date

01/06/2007

Publisher version

https://iopscience.iop.org/article/10.1086/511953/meta

Language

English