Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/232814

Title

The optically unbiased GRB host (TOUGH) survey VI: radio observations at z less than or equal to 1 and consistency with typical star-forming galaxies

Author(s)

Michalowski, M. J.;  Kamble, A.;  Hjorth, J.;  Malesani, D.;  Reinfrank, R. F.;  Bonavera, L.;  Castro Ceron, J. M.;  Ibar, E.;  Dunlop, J. S.;  Fynbo, J. P. U.;  Garrett, M. A.;  Jakobsson, P.;  Kaplan, D. L.;  Kruhler, T.;  Levan, A. J.;  Massardi, M.;  Pal, S.;  Sollerman, J.;  Tanvir, N. R.;  Van Der Horst, A. J.;  Watson, D.;  Wiersema, K.

Abstract

The objective of this paper is to determine the level of obscured star formation activity and dust attenuation in a sample of gamma-ray burst (GRB) hosts, and to test the hypothesis that GRB hosts have properties consistent with those of the general star-forming galaxy populations. We present a radio continuum survey of all z < 1 GRB hosts in The Optically Unbiased GRB Host (TOUGH) sample supplemented with radio data for all (mostly pre-Swift) GRB-SN hosts discovered before 2006 October. We present new radio data for 22 objects and have obtained a detection for three of them (GRB 980425, 021211, 031203; none in the TOUGH sample), increasing the number of radio-detected GRB hosts from two to five. The star formation rate (SFR) for the GRB 021211 host of ~825 M ☉ yr–1, the highest ever reported for a GRB host, places it in the category of ultraluminous infrared galaxies. We found that at least ~63% of GRB hosts have SFR < 100 M ☉ yr–1 and at most ~8% can have SFR > 500 M ☉ yr–1. For the undetected hosts the mean radio flux (<35 μJy 3σ) corresponds to an average SFR < 15 M ☉ yr–1. Moreover, gsim 88% of the z lsim 1 GRB hosts have ultraviolet dust attenuation A UV < 6.7 mag (visual attenuation AV < 3 mag). Hence, we did not find evidence for large dust obscuration in a majority of GRB hosts. Finally, we found that the distributions of SFRs and A UV of GRB hosts are consistent with those of Lyman break galaxies, Hα emitters at similar redshifts, and of galaxies from cosmological simulations. The similarity of the GRB population with other star-forming galaxies is consistent with the hypothesis that GRBs, a least at z lsim 1, trace a large fraction of all star formation, and are therefore less biased indicators than once thought.

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. 755, no. 2 (Aug 2012), article no. 85

Publication year

2012

FOR Code(s)

0201 Astronomical and Space Sciences;  0305 Organic Chemistry;  0306 Physical Chemistry (Incl. Structural)

Keyword(s)

Dust;  Extinction galaxies;  Galaxy evolution;  Gamma-ray burst;  ISM galaxies;  Radio continuum;  Star formation

Publisher

Institute of Physics Publishing

ISSN

0004-637X

Publisher URL

http://dx.doi.org/10.1088/0004-637x/755/2/85

Copyright

Copyright © 2012. The American Astronomical Society. All rights reserved. The American Astronomical Society does not allow Swinburne Research Bank to archive either the accepted manuscript or the published version of the article. However you can find an earlier version of the full text here: http://arxiv.org/abs/1205.4239

Peer reviewed