Swift observations of GRB 050712 |
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| Authors: | Massimiliano De Pasquale Dirk Grupe T S Poole A A Breeveld S Zane S R Rosen M J Page K O Mason D N Burrows H A Krimm N Gehrels J A Nousek P W A Roming S Kobayashi B Zhang |
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| Institution: | Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT;Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802, USA;NASA/Goddard Space Science Flight Center, Greenbelt, MD 20771, USA;Universities Space Research Association, Columbia, MD 21044, USA;Astrophysics Research Institute, Liverpool John Moore University, Twelve Quays House, Birkenhead CH4 1LD;Department of Physics, University of Nevada, Las Vegas, NV 89154, USA |
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| Abstract: | We present the results of X-ray and optical observations of GRB 050712 performed by Swift . The X-ray light curve of this burst exhibits episodes of flares in the first 1000 s, the same epoch at which the UVOT detected an optical counterpart. A shallow X-ray decay, with a decay slope of α=?0.73 , followed and lasted ～70 ks. This behaviour can be explained in terms of activity of the gamma-ray burst 'inner engine', with the possibility that the last flare is caused by the interaction of the ejecta with the surrounding medium.
We also find interesting spectral parameters for the X-ray emission. In particular, data suggest the presence of an intrinsic absorption in the first 1000 s, which can be explained if circumburst medium clouds lie along the line of sight. |
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| Keywords: | gamma-rays: bursts |
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