1997/01/22 by Boris Stern, B. E. Stern, Stern, Boris +4
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics (astro-ph) #FOS: Physical sciences #Gamma-ray bursts and supernovae #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9701171
5 pages; esa_sp_latex style; 3 postscript figure; Comments to [email protected]; to appear in the proceeding of the 2nd INTEGRAL Workshop; St.Malo, France, September 1996
arxiv created 1997/01/22 · openalex publication_date 1997/01/22 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The average peak-aligned profile of all bursts detected by BATSE with sufficient data quality has a simple ``stretched'' exponential shape, F ~ exp[-(t/t0)1/3], where t is the time measured from the time for the peak flux of the event, and t0 is a time constant. We study the behaviour of t0 of both the post-peak and the pre-peak slopes of the average time profile as a function of the peak brightness range of the burst sample. We found that the post-peak slope shows time dilation when comparing bright and dim bursts, while the pre-peak slope hardly changes. Thus dimmer bursts have a different shape -- they are more asymmetric. This shape-brightness correlation is observed at a 99.6% confidence level. Such a correlation has a natural explanation within the pulse avalanche model, which is briefly described. Complex events, consisting of many pulses are more symmetric and are intrinsically brighter. Bursts consisting of one or a few pulses are intrinsically weaker and more asymmetric. For such a correlation to be observable requires that the luminosity distance distribution of GRBs to be different from a power-law.