Non-Isotropic Angular Distribution for Very Short-Time Gamma-Ray Bursts
Abstract
While most gamma-ray bursts (GRBs) are now believed to be from cosmological distances, the origin of very short-time GRBs is still not known. In the past, we have shown that GRBs with time duration (T90) less than 100 ms may form a separate class of GRBs based on the hardness and time distribution of these events. We have also shown that the ln N ln S distribution is consistent with the expectation of quasi-Euclidean distribution of sources. In this paper, we report the study of the angular location of these GRBs showing a strong deviation from isotropy within the Galactic coordinates of plus 180 degrees < longitude < 90 degrees and -30 degrees < latitude < 30 degrees. We have studied the rest of the GRBs and do not find a similar deviation. This further indicates that the very-short GRBs likely form a separate class of GRBs, most probably from sources of Galactic or near solar origin.
Keywords
Cite
@article{arxiv.astro-ph/0105059,
title = {Non-Isotropic Angular Distribution for Very Short-Time Gamma-Ray Bursts},
author = {David B. Cline and C. Matthey and S. Otwinowski},
journal= {arXiv preprint arXiv:astro-ph/0105059},
year = {2009}
}