05/29/02
DAIGNE Frederic Service d'Astrophysique du CEA
Centre d'Etudes de Saclay - Orme des Merisiers - Batiment 709 SF2A- PCHE-
91191 Gif sur Yvette Cedex, France
Presentation 1 : Poster
Are X-ray flashes a peculiar class of (soft) gamma-ray bursts ?
F. Daigne, C. Barraud and R. Mochkovitch
Heise et al. (2001) have reported the identification of a new class of sources by Beppo-SAX : the X-ray flashes (XRFs). They have several common properties with gamma-ray bursts (GRBs) (duration comparable to long GRB durations, variable light curves and non-thermal spectra). These properties suggest that XRFs are a peculiar class of very soft GRBs. We have investigated the two main possibilities : either XRFs are normal GRBs which are apparently soft due to a high redshift; or they have the same origin than GRBs but are intrinsically softer due to peculiar physical circumstances. We present here our first results.