Are Short GRBs Really Hard?
Abstract
Thanks to the rapid position notice and response by HETE-2 and Swift, the X-ray afterglow emissions have been found for four recent short gamma-ray bursts (GRBs; GRB 050509b, GRB 050709, GRB 050724, and GRB 050813). The positions of three out of four short GRBs are coincident with galaxies with no current or recent star formation. This discovery tightens the case for a different origin for short and long GRBs. On the other hand, from the prompt emission point of view, a short GRB shows a harder spectrum comparing to that of the long duration GRBs according to the BATSE observations. We investigate the prompt emission properties of four short GRBs observed by Swift/BAT. We found that the hardness of all four BAT short GRBs is in between the BATSE range for short and long GRBs. We will discuss the spectral properties of short GRBs including the short GRB sample of Konus-Wind and HETE-2 to understand the hard nature of the BATSE short GRBs.
Cite
@article{arxiv.astro-ph/0605717,
title = {Are Short GRBs Really Hard?},
author = {T. Sakamoto and L. Barbier and S. Barthelmy and J. Cummings and E. Fenimore and N. Gehrels and D. Hullinger and H. Krimm and C. Markwardt and D. Palmer and A. Parsons and G. Sato and J. Tueller and R. Aptekar and T. Cline and S. Golenetskii and E. Mazets and V. Pal'shin and G. Ricker and D. Lamb and J. -L. Atteia and N. Kawai},
journal= {arXiv preprint arXiv:astro-ph/0605717},
year = {2015}
}
Comments
5 pages, 8 figures. To appear in the proceedings of "Gamma Ray Bursts in the Swift Era", eds. S. Holt, N. Gehrels & J. Nousek