Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/48859

Title

The galaxy population hosting gamma-ray bursts

Author(s)

Savaglio, S.;  Glazebrook, Karl;  Le Borgne, D.

Abstract

We present the most extensive and complete study of the properties for the largest sample (46 objects) of gamma-ray burst (GRB) host galaxies. The redshift interval and the mean redshift of the sample are 0 < z < 6.3 and z = 0.96 (look-back time: 7.2 Gyr), respectively; 89% of the hosts are at z ≤ 1.6. Optical-near-IR (NIR) photometry and spectroscopy are used to derive stellar masses, star formation rates (SFRs), dust extinctions, and metallicities. The average stellar mass is 109.3 M sun, with a 1σ dispersion of 0.8 dex. The average metallicity for a subsample of 17 hosts is about 1/6 solar and the dust extinction in the visual band (for a subsample of 10 hosts) is AV = 0.5. We obtain new relations to derive SFR from [O II] or UV fluxes, when Balmer emission lines are not available. SFRs, corrected for dust extinction, aperture-slit loss, and stellar Balmer absorption are in the range 0.01-36 M sun yr–1. The median SFR per unit stellar mass (specific SFR) is 0.8 Gyr–1. Equivalently the inverse quantity, the median formation timescale, is 1.3 Gyr. Most GRBs are associated with the death of young massive stars, more common in star-forming galaxies. Therefore, GRBs are an effective tool to detect star-forming galaxies in the universe. Star-forming galaxies at z < 1.6 are a faint and low-mass population, hard to detect by conventional optical-NIR surveys, unless a GRB event occurs. There is no compelling evidence that GRB hosts are peculiar galaxies. More data on the subclass of short GRB are necessary to establish the nature of their hosts.

Publication type

Journal article

Research centre

Swinburne University of Technology. Faculty of Information and Communication Technologies. Centre for Astrophysics and Supercomputing

Source

Astrophysical Journal, Vol. 691, no. 1 (Jan 2009), pp. 182-211

Publication year

2009

Keyword(s)

Abundances;  Core-collapse supernovae;  Cosmology;  Deep deep survey;  Digital sky survey;  Evolution;  Fundamental parameters;  Galaxies;  Goods-north field;  H-II;  High-redshift galaxies;  Hubble-space telescope;  Mass-metallicity relation;  Observations;  Regions;  Star-forming galaxies;  Stellar masses

Publisher

Institute of Physics Publishing

ISSN

0004-637X

Publisher URL

http://dx.doi.org/10.1088/0004-637x/691/1/182

Copyright

Copyright © 2009 The American Astronomical Society. All rights reserved.

Peer reviewed