Properties of a Gamma-Ray Burst Host Galaxy at z ~ 5
Abstract
We describe the properties of the host galaxy of the gamma-ray burst GRB 060510B based on a spectrum of the burst afterglow obtained with the Gemini North 8 m telescope. The galaxy lies at a redshift of z=4.941, making it the fourth highest spectroscopically identified burst host. However, it is the second highest redshift galaxy for which the quality of the spectrum permits a detailed metallicity analysis. The neutral hydrogen column density has a logarithmic value of 21.0-21.2 cm-2, and the weak metal lines of Ni, S, and Fe show that the metallicity is in excess of a tenth of solar, which is far above the metallicities in damped Lyα absorbers at high redshift. The tightest constraint is from the Fe lines, which place [Fe/H] in excess of -0.8. We argue that the results suggest that metallicity bias could be a serious obstacle to inferring star formation from the GRB population, and we consider how future higher quality measurements could be used to resolve this issue.
Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini Partnership: the National Science Foundation (US), the Particle Physics and Astronomy Research Council (UK), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), CNPq (Brazil), and CONICET (Argentina)- Publication:
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The Astrophysical Journal
- Pub Date:
- July 2007
- DOI:
- 10.1086/520047
- arXiv:
- arXiv:0705.4101
- Bibcode:
- 2007ApJ...663L..57P
- Keywords:
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- Cosmology: Observations;
- Galaxies: Abundances;
- Galaxies: Distances and Redshifts;
- Galaxies: Evolution;
- Gamma Rays: Bursts;
- Astrophysics
- E-Print:
- Accepted for publication in ApJ Letters