GRB 051210: Swift detection of a short gamma ray burst
INAF – Istituto di Astrofisica Spaziale e Fisica Cosmica di Palermo, Italy e-mail: email@example.com
2 Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802, USA
3 Department of Physics, University of Nevada, 4505 Maryland Parkway, Las Vegas, NV 89154-4002, USA
4 NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
5 Universities Space Research Association 10211 Wincopin Circle, Suite 500 Columbia, Maryland 21044, USA
6 INAF – Osservatorio Astronomico di Brera, via Bianchi 46, 23807 Merate, Italy
7 ASI Science Data Center, via Galileo Galilei, 00044 Frascati, Italy
8 Università degli studi di Milano-Bicocca, Dipartimento di Fisica, Piazza delle Scienze 3, 20126 Milan, Italy
9 Department of Physics, Pennsylvania State University, PA 16802, USA
10 Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH, UK
11 Los Alamos National Laboratory, MS B244, NM 87545, USA
Accepted: 21 April 2006
Aims.The short/hard GRB 051210 was detected and located by the Swift-BAT instrument and rapidly pointed towards by the narrow field instruments. The XRT was able to observe a bright, rapidly fading X-ray emission. We present the analysis of the prompt and afterglow emission of this event.
Methods.The BAT spectrum is a power-law with photon index . The X-ray light curve decays with slope and shows a small flare in the early phases. The spectrum can be described with a power law with photon index and absorption cm-2.
Results.We find that the X-ray emission is consistent with the hypothesis that we are observing the curvature effect of a GRB that occurred in a low density medium, with no detectable afterglow attributable to an external shock. We estimate the density of the circumburst medium to be lower than cm-3. We also discuss different hypothesis on the possible origin of the flare.
Key words: gamma rays: bursts / X-rays: bursts
© ESO, 2006