Astronomy and Astrophysics – Astrophysics
Scientific paper
2006-01-06
Astrophys.J.647:1213-1237,2006
Astronomy and Astrophysics
Astrophysics
Submitted to ApJ on December 16. Revised following referee's comments. Accepted for publication in ApJ. Minor correction to Fi
Scientific paper
10.1086/505457
We present observations of the early X-ray emission for a sample of 40 gamma-ray bursts (GRBs) obtained using the Swift satellite for which the narrow-field instruments were pointed at the burst within 10 minutes of the trigger. Using data from the Burst Alert and X-Ray Telescopes, we show that the X-ray light curve can be well described by an exponential that relaxes into a power law, often with flares superimposed. The transition time between the exponential and the power law provides a physically defined timescale for the burst duration. In most bursts the power law breaks to a shallower decay within the first hour, and a late emission "hump" is observed which can last for many hours. In other GRBs the hump is weak or absent. The observed variety in the shape of the early X-ray light curve can be explained as a combination of three components: prompt emission from the central engine; afterglow; and the late hump. In this scenario, afterglow emission begins during or soon after the burst and the observed shape of the X-ray light curve depends on the relative strengths of the emission due to the central engine and that of the afterglow. There is a strong correlation such that those GRBs with stronger afterglow components have brighter early optical emission. The late emission hump can have a total fluence equivalent to that of the prompt phase. GRBs with the strongest late humps have weak or no X-ray flares.
Barthelmy Scott
Beardmore Andrew
Burrows David N.
Campana Sergio
Cannizzo John
No associations
LandOfFree
The early X-ray emission from GRBs 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 The early X-ray emission from GRBs, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The early X-ray emission from GRBs will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-110015