GRB 060121: Implications of a Short/Intermediate Duration Gamma-Ray Burst at High Redshift
Abstract
Since the discovery of the first short-hard gamma-ray burst afterglows in 2005, the handful of observed events have been found to be embedded in nearby (z < 1), bright underlying galaxies. We present multiwavelength observations of the short-duration burst GRB 060121, which is the first observed to clearly outshine its host galaxy (by a factor >10^2). A photometric redshift for this event places the progenitor at a most probable redshift of z = 4.6, with a less probable scenario of z = 1.7. In either case, GRB 060121 could be the farthermost short-duration GRB detected to date and implies an isotropic-equivalent energy release in gamma-rays comparable to that seen in long-duration bursts. We discuss the implications of the released energy on the nature of the progenitor. These results suggest that GRB 060121 may belong to a family of energetic short-duration events, lying at z > 1 and whose optical afterglows would outshine their host galaxies, unlike the first short-duration GRBs observed in 2005. The possibility of GRB 060121 being an intermediate duration burst is also discussed.
Cite
@article{arxiv.astro-ph/0605516,
title = {GRB 060121: Implications of a Short/Intermediate Duration Gamma-Ray Burst at High Redshift},
author = {A. de Ugarte Postigo and A. J. Castro-Tirado and S. Guziy and J. Gorosabel and G. Johannesson and M. A. Aloy and S. McBreen and D. Q. Lamb and N. Benitez and M. Jelinek and S. B. Pandey and D. Coe and M. D. Perez-Ramirez and F. J. Aceituno and M. Alises and J. A. Acosta-Pulido and G. Gomez and R. Lopez and T. Q. Donaghy and Y. E. Nakagawa and T. Sakamoto and G. R. Ricker and F. R. Hearty and M. Bayliss and G. Gyuk and D. G. York},
journal= {arXiv preprint arXiv:astro-ph/0605516},
year = {2008}
}
Comments
4 pages, 4 figures. Submitted to ApJL