Gamma Ray Burst Flares as observed by Swift XRT
Abstract
About 40 of the Gamma Ray Bursts observed with the XRT on board of the Swift satellites show flare activity Some of these flares have a very large Fluence and the energy involved is of the order of the energy emitted in the 0 2 -- 10 keV band during the whole afterglow Mini-flares are often detectable on the light curve Flares occur at any place along the XRT light curve Here we will present a study based on a rather large sample of flares observed during the first year of the mission We will discuss the correlation time of occurrence versus flare duration and illustrate the distribution of the energetic involved for those flares for which the redshift of the GRB is known The distribution of the flare Fluence normalized to the total afterglow emission will also be discussed for those flares that do not have a redshift Flares may indicate that the central engine remains active for a large period after the prompt emission and may be the result of internal shocks following new discontinuous injection of energy For the brightest flares we will outline via the flare morphology time of occurrence and spectral evolution parameters that may constraint the mechanism of emission Finally we will compare the characteristics of nearby flares with those of the more distant GRB
- Publication:
-
36th COSPAR Scientific Assembly
- Pub Date:
- 2006
- Bibcode:
- 2006cosp...36.3689C