Talk detail

Participant	Mochkovitch, Robert
Institution	Institut d'Astrophysique de Paris - 98bis Bd Arago - Paris - - France

Session	GRB2	Accepted	Yes	Order	3	Time	15:00 - 15:30
Talk	Oral abstract	Title	Internal shocks: a critical review
Co-authors	R. Mochkovitch, F. Daigne, R. Hascoet
Abstract	I will describe the internal shock model for the prompt emission of GRBs, trying to give a fair account of the pros and the cons. I will show examples of the model success but also list the problems it faces. I will then try to classify these problems from the less to the most severe ones.

Session	GRB5	Accepted	Yes	Order	2	Time	14:30 - 15:00
Talk	Oral abstract	Title	Extended X-ray plateaus, long term activity of the central engine and the reverse shock
Co-authors	R. Hascoet, F.Daigne
Abstract	Some early X-ray afterglows observed with Swift XRT exhibit a flat plateau phase that can last t_plateau ~ several 10^4 s as in GRB 060729 or in the recent weak and nearby event GRB 120422A. If these extended plateaus are explained by delayed energy injection into the forward shock they require a ratio of the delayed to prompt energy that can exceed 100. We show that if the source remains active for a duration comparable or slightly smaller than t_plateau the progation of the reverse shock can explain the plateau at a much reduced energy cost.