TY - JOUR
T1 - An HST study of three very faint GRB host galaxies
AU - Jaunsen, A.O.
AU - Andersen, M.I.
AU - Hjorth, J.
AU - Fynbo, J.P.U.
AU - Holland, S.T.
AU - Thomsen, Bente
AU - Gorosabel, J.
AU - Schaefer, B.E.
AU - Bjornsson, G.
AU - Natarajan, P.
AU - Tanvir, N.R.
PY - 2003
Y1 - 2003
N2 - As part of the HST/STIS GRB host survey program we present the detection of three faint gamma-ray burst (GRB) host galaxies based on an accurate localisation using ground-based data of the optical afterglows (OAs). A common property of these three hosts is their extreme faintness. The location at which GRBs occur with respect to their host galaxies and surrounding environments are robust indicators of the nature of GRB progenitors. The bursts studied here are among the four most extreme outliers, in terms of relative distance from the host center, in the recent comprehensive study of Bloom et al. (2002). We obtain a revised and much higher probability that the galaxies identified as hosts indeed are related to the GRBs (P(n(chance))=0.69, following Bloom et al. 2002), thereby strengthening the conclusion that GRBs are preferentially located in star-forming regions in their hosts. Apart from being faint, the three hosts consist of multiple structures, indicative of merging and active star-formation. For one of the hosts, GRB 980329, we estimate a photometric redshift of zsimilar to3.5.
AB - As part of the HST/STIS GRB host survey program we present the detection of three faint gamma-ray burst (GRB) host galaxies based on an accurate localisation using ground-based data of the optical afterglows (OAs). A common property of these three hosts is their extreme faintness. The location at which GRBs occur with respect to their host galaxies and surrounding environments are robust indicators of the nature of GRB progenitors. The bursts studied here are among the four most extreme outliers, in terms of relative distance from the host center, in the recent comprehensive study of Bloom et al. (2002). We obtain a revised and much higher probability that the galaxies identified as hosts indeed are related to the GRBs (P(n(chance))=0.69, following Bloom et al. 2002), thereby strengthening the conclusion that GRBs are preferentially located in star-forming regions in their hosts. Apart from being faint, the three hosts consist of multiple structures, indicative of merging and active star-formation. For one of the hosts, GRB 980329, we estimate a photometric redshift of zsimilar to3.5.
KW - gamma rays : bursts
KW - cosmology : observations
KW - galaxies : starburst
U2 - 10.1051/0004-6361:20030154
DO - 10.1051/0004-6361:20030154
M3 - Journal article
SN - 0004-6361
VL - 402
SP - 125
EP - 132
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
IS - 1
ER -