Astronomy and Astrophysics – Astrophysics
Scientific paper
2005-04-03
Astron.Astrophys.437:411-418,2005
Astronomy and Astrophysics
Astrophysics
Accepted for publication in A&A. 8 pages, 5 figures
Scientific paper
10.1051/0004-6361:20052783
We report on ground-based and HST(+STIS) imaging of the afterglow and host galaxy of the Gamma-Ray Burst (GRB) of March 5 2002. The GRB occurred in a R=25.17+/-0.14 galaxy, which apparently is part of an interacting system. The lightcurve of the optical afterglow shows a rebrightening, or at least a plateau, 12--16 days after the gamma-ray event. UBVRIK' multi-band imaging of the afterglow ~12 days after the GRB reveals a blue spectral energy distribution (SED). The SED is consistent with a power-law with a spectral index of \beta=-0.63+/-0.16, but there is tentative evidence for deviations away from a power-law. Unfortunately, a spectroscopic redshift has not been secured for GRB020305. From the SED we impose a redshift upper limit of z ~< 2.8, hence excluding the pseudo redshift of 4.6 reported for this burst. We discuss the possibilities for explaining the lightcurve, SED and host galaxy properties for GRB 020305. The most natural interpretation of the lightcurve and the SED is an associated supernova (SN). Our data can not precisely determine the redshift of the GRB. The most favoured explanation is a low redshift (z~0.2) SN, but a higher redshift (z>0.5) SN can not be excluded. We also discuss less likely scenarios not based on SNe, like a burst occurring in a z=2.5 galaxy with an extinction curve similar to that of the Milky Way.
Bersier David
Burud Ingunn
Castro Cerón José María
Castro-Tirado Alberto J.
Fruchter Andrew
No associations
LandOfFree
A possible bright blue SN in the afterglow of GRB 020305 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A possible bright blue SN in the afterglow of GRB 020305, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A possible bright blue SN in the afterglow of GRB 020305 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-302087