An HST study of three very faint GRB host galaxies *
1
European Southern Observatory, Casilla 19001, Santiago 19, Chile e-mail: ajaunsen@eso.org
2
Division of Astronomy, PO Box 3000, 90014 University of Oulo, Finland e-mail: michael.andersen@oulo.fi
3
Astrophysikalische Institut Potsdam, An der Sterwarte 16, 14482 Potsdam, Germany e-mail: mandersen@aip.de
4
Astronomical Observatory, University of Copenhagen, 2100 Copenhagen Ø, Denmark e-mail: jens@astro.ku.dk
5
Department of Physics and Astronomy, University of Aarhus, 8000 Århus C, Denmark e-mail: jfynbo@phys.au.dk, bt@phys.au.dk
6
Department of Physics, University of Notre Dame, Notre Dame, IN 46556–5670, USA e-mail: sholland@nd.edu
7
Danish Space Research Institute Juliane Maries Vej 30, 2100 Copenhagen Ø, Denmark e-mail: jgu@dsri.dk
8
Instituto de Astrofísica de Andalucía (IAA-CSIC), PO Box 03004, 18080 Granada, Spain e-mail: jgu@iaa.es
9
Laboratorio de Astrofísica Espacial y Física Fundamental (LAEFF-INTA), PO Box 50727, 28080, Madrid, Spain e-mail: jgu@laeff.esa.es
10
University of Texas, Department of Astronomy, C-1400, Austin, TX–78712, USA e-mail: schaefer@astro.as.utexas.edu
11
Science Institute, Dunhagi 3, University of Iceland 107 Reykjavik, Iceland e-mail: gulli@raunvis.hi.is
12
Department of Astronomy, Yale University, 265 Whitney Avenue, New Haven, CT 06511, USA e-mail: priya@astro.yale.edu
13
Department of Physical Sciences, University of Hertfordshire, College Lane, Hatfield, Hertfordshire AL10 9AB, UK e-mail: nrt@star.herts.ac.uk
Corresponding author: A. O. Jaunsen, ajaunsen@eso.org
Received:
16
April
2002
Accepted:
28
January
2003
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. ([CITE]).
We obtain a revised and much higher probability that the galaxies
identified as hosts indeed are related to the GRBs (
, following Bloom et al. [CITE]), 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 
.
Key words: gamma rays: bursts / cosmology: observations / galaxies: starburst
Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Institute. STScI is operated by the association of Universities for Research in Astronomy, Inc. under the NASA contract NAS 5-26555. Based on observations made with ESO Telescopes at the La Silla or Paranal Observatories under programme ID 60.A-0552. Based on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofiscia de Canarias
© ESO, 2003