Sub-Energetic GRB 031203 as a Cosmic Analogue to GRB 980425.

Soderberg, A. M. ; Kulkarni, S. R. ; Berger, E. ; Fox, D. W. ; Sako, M.

Technical Information Center Oak Ridge Tennessee

关键词: Cosmic gamma bursts;    Afterglow;    Luminosity;    Spectroscopy;    Red shift;   

RP-ID  :  DE2004829715

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

Over the six years since the discovery of the (gamma)-ray burst GRB 980425, associated with the nearby (distance (approx)40 Mpc) supernova 1998bw, astronomers have fiercely debated the nature of this event. Relative to bursts located at cosmological distances, (redshift, z (approx) 1), GRB 980425 was under-luminous in (gamma)-rays by three orders of magnitude. Radio calorimetry showed the explosion was sub-energetic by a factor of 10. Here, the authors report observations of the radio and X-ray afterglow of the recent z = 0.105 GRB031203 and demonstrate that it too is sub-energetic. The result, when taken together with the low (gamma)-ray luminosity, suggest that GRB031203 is the first cosmic analogue to GRB980425. They find no evidence that this event was a highly collimated explosion viewed off-axis. Like GRB980425, GRB031203 appears to be an intrinsically sub-energetic (gamma)-burst. Such sub-energetic events have faint afterglows. Intensive follow-up of faint bursts with smooth (gamma)-ray light curves (common to both GRBs 031203 and 980425) may enable the authors to reveal their expected large population.