Gamma-ray burst classes found in the RHESSI data sample

0355599 - ASÚ 2011 RIV LT eng J - Journal Article
Řípa, J. - Wigger, C. - Huja, D. - Hudec, René
Gamma-ray burst classes found in the RHESSI data sample.
Baltic Astronomy. Roč. 18, 3-4 (2009), s. 305-309. ISSN 1392-0049.
[INTEGRAL/BART workshop 2009. Karlovy Vary, 26.03.2009-29.03.2009]
R&D Projects: GA ČR GD205/08/H005; GA ČR GA205/08/1207
Grant - others:ESA(XE) ESA-PECS project No. 98023
Institutional research plan: CEZ:AV0Z10030501
Keywords : gamma rays * bursts
Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics
Impact factor: 1.032, year: 2009

A sample of 427 gamma-ray bursts (GRBs), measured by the RHESSI satellite, is studied statistically to determine the number of ORB groups. Previous studies based on the BATSE Catalog and recently on the Swift data claim the existence of an intermediate GRB group, besides the long and short groups. Using only the GRB durations T-90 and chi(2) or F-test, we have not found any statistically significant intermediate group. However, the maximum likelihood ratio test, one-dimensional as well as two-dimensional hardness vs. T-90 plane, reveal the reality of an intermediate group. Hence, the existence of this group follows not only from the BATSE and Swift datasets, but also from the RHESSI results.
Permanent Link: http://hdl.handle.net/11104/0194333