Talk detail

Participant	Pozanenko, Alexei
Institution	Space Research Institute (IKI) - Profsoyuznaya 84/32 - Moscow - Moscow - Russia

Session	GRB5	Accepted		Order	Time
Talk	Oral abstract	Title	Model of the extended emission of short gamma-ray bursts
Co-authors
Abstract	The existence of extended emission is an intriguing property of short-duration gamma-ray bursts, because the nature of the EE is still unclear. It might be a rising X-ray afterglow, or it could be a manifestation of the prolonged activity of a central engine. We consider short duration gamma-ray bursts, emphasizing the common properties of both short bursts and short bursts with EE. Assuming that the EE with broad dynamic range is a common property of short bursts, we propose a two jet model which can describe both short main episode of hard spectra emission, specific for short bursts, and softer spectra EE by different off axis position of observer. The model involves a short-duration jet, which is powered by heating due to neutrino annihilation, and a long-lived Blandford–Znajek jet with a significantly narrow opening angle. Our proposed model is a plausible mechanism for short-duration burst energization. It can explain short bursts both with and without EE within a single class of progenitor.

Session	GRB4	Accepted		Order	Time
Talk	Oral abstract	Title	The dependence of the spectral lag on the energy
Co-authors
Abstract	We investigated dependence of a spectral lag against energy band based on bright GRBs registered by INTEGRAL observatory. It is found that for simple structure burst or separate pulses of multi-peaked bursts, the energy-dependent lag can be approximated by a simple law. We have not found any negative lag in well separated pulses, while investigating the time profile of the whole burst negative lag may appear due to overlapping of pulses with different spectral parameters. We also discuss a possible nature of the spectral lag.