2005/05/26 by P. Jakobsson, G. Bjornsson, G. Björnsson +13
Physics and Astronomy · #Astrophysical Phenomena and Observations #Gamma-ray bursts and supernovae #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2005.09289.x
published as Mon.Not.Roy.Astron.Soc. 362 (2005) 245-251 · 8 pages, 5 figures. MNRAS, in press
arxiv created 2005/05/26 · openalex publication_date 2005/08/17 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We report the result of a search for Lyα emission from the host galaxies of the gamma-ray bursts (GRBs) 030226 (z= 1.986), 021004 (z= 2.335) and 020124 (z= 3.198). We find that the host galaxy of GRB 021004 is an extended (around 8 kpc) strong Lyα emitter with a rest-frame equivalent width (EW) of 68+12−11Å, and a star formation rate of 10.6 ± 2.0 M⊙ yr−1. We do not detect the hosts of GRB 030226 and GRB 020124, but the upper limits on their Lyα fluxes do not rule out large rest-frame EWs. In the fields of GRB 021004 and GRB 030226 we find seven and five other galaxies, respectively, with excess emission in the narrow-band filter. These galaxies are candidate Lyα-emitting galaxies in the environment of the host galaxies. We have also compiled a list of all z≳ 2 GRB hosts, and demonstrate that a scenario where they trace star formation in an unbiased way is compatible with current observational constraints. Fitting the z= 3 luminosity function (LF) under this assumption results in a characteristic luminosity of R*= 24.6 and a faint-end slope of α=−1.55, consistent with the LF measured for Lyman-break galaxies.