2006/11/30 by J. X. Prochaska, H.‐W. Chen, H. -W. Chen +11 · 4 citations
Engineering · Physics and Astronomy · #Afterglow #Astronomy and Astrophysical Research #CCD and CMOS Imaging Sensors #Gamma-ray burst #Gamma-ray bursts and supernovae #Interstellar medium #Ionization #Spectral line #Telescope #astro-ph
paper · pdf · doi:10.1086/510239
52 pages, 18 figures. Accepted to ApJS. The spectra will be published with the paper and is also available upon request. A complete version with full-resolution figures is available at http://lambda.uchicago.edu/public/tmp/echelle.pdf
arxiv created 2007/01/04 · openalex publication_date 2007/02/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present optical echelle spectra of four gamma-ray burst (GRB) afterglows (GRB 050730, GRB 050820, GRB 051111, and GRB 060418) discovered during the first 1.5 yr of operation of the Swift satellite and localized by either the Swift telescope or follow-up ground-based imaging. We analyze the spectra to derive accurate column density measurements for the transitions arising in the interstellar medium (ISM) of the GRB host galaxies. These measurements can be used to constrain the physical properties of the ISM, including the metallicity, dust-to-gas ratio, ionization state, and chemical abundances of the gas. We also present measurements of the strong Mg II systems in the GRB afterglow spectra. With the publication of this paper, we provide the first data release of echelle afterglow spectra by the GRAASP collaboration to the general community.