Astronomy and Astrophysics – Astrophysics
6 pages, 5 figures. To be published in MNRAS Letters
GRB050223 was discovered by the Swift Gamma-Ray Burst Explorer on 23 February 2005 and was the first Gamma-Ray Burst to be observed by both Swift and XMM-Newton. At the time of writing (May 2005), it has one of the faintest GRB afterglows ever observed. The spacecraft could not slew immediately to the burst, so the first X-ray and optical observations occurred approximately 45 minutes after the trigger. Although no optical emission was found by any instrument, both Swift and XMM-Newton detected the fading X-ray afterglow. Combined data from both of these observatories show the afterglow to be fading monotonically as 0.99 +0.15/-0.12 over a time frame between 45 minutes to 27 hours post-burst. Spectral analysis, allowed largely by the higher through-put of XMM-Newton, implies a power-law with a slope of Gamma=1.75 +0.19/-0.18 and shows no evidence for absorption above the Galactic column of 7 x 10^20 cm^-2. From the X-ray decay and spectral slopes, a low electron power-law index of p = 1.3-1.9 is derived; the slopes also imply that a jet-break has not occured up to 27 hours after the burst. The faintness of GRB050223 may be due to a large jet opening or viewing angle or a high redshift.
Beardmore Andrew P.
Burrows David N.
Cummings Jay R.
GRB050223: A faint Gamma-Ray Burst discovered by Swift 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 GRB050223: A faint Gamma-Ray Burst discovered by Swift, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and GRB050223: A faint Gamma-Ray Burst discovered by Swift will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-723200