Astronomy and Astrophysics – Astrophysics
Scientific paper
2006-04-20
Mon.Not.Roy.Astron.Soc.Lett. 370 (2006) L33-L37
Astronomy and Astrophysics
Astrophysics
6 pages, 5 figures, 2 tables. Accepted for publication in MNRAS Letter
Scientific paper
10.1111/j.1745-3933.2006.00183.x
GRB 990413 shows a very hard spectrum (with a low energy spectral component F(E) \propto E^{2.49}) which is well represented by a black body model with characteristic temperature ~70 keV. It thus belongs to the subset of GRBs which might be revealing a thermal phase. We find that the temperature/luminosity evolution is consistent with that found in the other ``thermal'' GRBs. The time resolved spectral analysis indicates the presence of a second non--thermal component contributing (for about 1 s) up to 30 per cent of the total flux. Differently from the other thermal GRBs, GRB 990413 shows significantly high level of variability and the evolution of the thermal/non--thermal spectral components is strongly correlated with the flux variations. This GRB thus offers the unique opportunity to test the standard fireball photospheric and internal shock phases and their reciprocal influence. GRB 990413 was not selected on the basis of its spectrum and thus hints to the possibility that this early behavior might be more common than currently known.
Bosnjak Z.
Celotti Annalisa
Ghirlanda Giancarlo
No associations
LandOfFree
GRB 990413: Insight into the thermal phase evolution does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with GRB 990413: Insight into the thermal phase evolution, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and GRB 990413: Insight into the thermal phase evolution will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-66537