1999/06/02 by A. J. Castro‐Tirado, Alberto Castro-Tirado, J. Gorosabel +1 · 3 citations
Engineering · Physics and Astronomy · #Astronomy #Astrophysics #CCD and CMOS Imaging Sensors #Context (archaeology) #Galaxy #Gamma-ray burst #Gamma-ray bursts and supernovae #Light curve #Luminosity #Physics #Power law #astro-ph
paper · pdf · doi:10.1051/aas:1999303
published as Astron.Astrophys.Suppl.Ser. 138 (1999) 449-450 · Accepted for publication in Astronomy and Astrophysics Supplement Series (special issue on "Gamma-ray bursts in the afterglow era"). 2 pages and 2 postscript figures
arxiv created 1999/06/02 · openalex publication_date 1999/09/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Since January 1997, we have monitored 15 GRB fields, detecting 6 optical/IR afterglows. We have revisited GRB 970508 and GRB 980326. For GRB 970508, we derive a power-law decay exponent (R-band). The luminosity of the host galaxy L relative to the characteristic luminosity is in the range 0.06-0.15, i.e. a dwarf galaxy. For GRB 980326, we derive a power-law decay exponent , taking into account the new upper limit for the host as provided by Bloom & Kulkarni (1998). This implies one of the fastest GRB optical decays ever measured. The fact that only about 50% of optical transients have been found within the γ/X-ray error boxes, suggest that either considerable intrinsic absorption is present or that some optical transients display a very fast decline. We also propose that the "secondary maximum" detected on 17 Apr. 1998 could be explained in the context of the "SN-like" light curves 2-3 weeks after the GRB, as recently suggested by Woosley (1999).