Pregled bibliografske jedinice broj: 984154
GRB 990413 : insight into the thermal phase evolution
GRB 990413 : insight into the thermal phase evolution // Monthly Notices of the Royal Astronomical Society: Letters, 370 (2006), 1; L33-L37 doi:10.1111/j.1745-3933.2006.00183.x (međunarodna recenzija, članak, znanstveni)
CROSBI ID: 984154 Za ispravke kontaktirajte CROSBI podršku putem web obrasca
Naslov
GRB 990413 : insight into the thermal phase evolution
Autori
Bošnjak, Željka ; Celotti, A. ; Ghirlanda, G.
Izvornik
Monthly Notices of the Royal Astronomical Society: Letters (1745-3925) 370
(2006), 1;
L33-L37
Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni
Ključne riječi
radiative processes: non-thermal: radiative processes: thermal: gamma-rays: bursts, radiative processes: non-thermal, radiative processes: thermal, gamma-rays: bursts
Sažetak
GRB 990413 shows a very hard spectrum [with a low-energy spectral component F(ν) ~ ν2.49] which is well represented by a blackbody model with characteristic temperature ~70 keV. It thus belongs to the subset of gamma-ray bursts (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 behaviour might be more common than currently known.
Izvorni jezik
Engleski
Znanstvena područja
Fizika
