Astronomy and Astrophysics – Astrophysics
Scientific paper
2006-10-24
Mon.Not.Roy.Astron.Soc.Lett.375:L46-L50,2007
Astronomy and Astrophysics
Astrophysics
5 pages, MNRAS in press. Minor chenges to text following referee suggestions
Scientific paper
10.1111/j.1745-3933.2006.00273.x
The detection of bright X-ray flares superimposed on the regular afterglow decay in Swift gamma-ray bursts has triggered theoretical speculations on their origin. We study the temporal properties of flares due to internal dissipation and external shock mechanisms. We first show that at least a sizable fraction of the flares cannot be related to external shock mechanisms, since external shock flares evolve on much longer time scales than observed. We then study flares from internal dissipation, showing that the temporal properties allow us to distinguish the emission of slow early shells from that of late faster shells. We show that, due to the rapid evolution of the detected flares, it is most likely that the flares are produced by relatively fast shells ejected by the central engine shortly before they are observed. This implies that the central engine must be active for, in some cases, as long as one day. We finally discuss the constraints and implications that this observation has on the properties and physics of the inner engine, and we elaborate on possible future observational tests on the flare sample to further understand their origin and physics.
Lazzati Davide
Perna Rosalba
No associations
LandOfFree
X-ray flares and the duration of engine activity in gamma-ray bursts 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 X-ray flares and the duration of engine activity in gamma-ray bursts, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and X-ray flares and the duration of engine activity in gamma-ray bursts will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-377915