On the thermal and double episode emissions in GRB 970828

Дата и время публикации : 2012-05-30T12:51:31Z

Авторы публикации и институты :
L. Izzo
R. Ruffini
C. L. Bianco
H. Dereli
M. Muccino
A. V. Penacchioni
G. Pisani
Jorge A. Rueda

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: 7 pages, 10 figures, submitted to ApJ
Первичная категория: astro-ph.HE

Все категории : astro-ph.HE, astro-ph.SR

Краткий обзор статьи: Following the recent theoretical interpretation of GRB 090618 and GRB 101023, we here interpret GRB 970828 in terms of a double episode emission: the first episode, observed in the first 40 s of the emission, is interpreted as the proto-black-hole emission; the second episode, observed after t$_0$+50 s, as a canonical gamma ray burst. The transition between the two episodes marks the black hole formation. The characteristics of the real GRB, in the second episode, are an energy of $E_{tot}^{e^+e^-} = 1.60 times 10^{53}$ erg, a baryon load of $B = 7 times 10^{-3}$ and a bulk Lorentz factor at transparency of $Gamma = 142.5$. The clear analogy with GRB 090618 would require also in GRB 970828 the presence of a possible supernova. We also infer that the GRB exploded in an environment with a large average particle density $<n> , approx 10^3$ part/cm$^3$ and dense clouds characterized by typical dimensions of $(4 – 8) times 10^{14}$ cm and $delta n/n propto 10$. Such an environment is in line with the observed large column density absorption, which might have darkened both the supernova emission and the GRB optical afterglow.

Category: Physics