TITLE: GCN CIRCULAR NUMBER: 7925 SUBJECT: GRB 080702A: Swift-XRT Team refined analysis DATE: 08/07/02 21:03:07 GMT FROM: Kim Page at U.of Leicester K.L. Page (U. Leicester) & M. De Pasquale (UCL-MSSL) report on behalf of the Swift-XRT team: We have analysed the first 3 orbits of Swift-XRT data obtained for GRB 080702A (De Pasquale et al., GCN Circ. 7920), covering 5.2 ks of Photon Counting mode data, between ~75 and 12.6 ks after the trigger. The UVOT-enhanced XRT position was given by Goad et al. in GCN Circ. 7923. The light-curve can be modelled by a broken power-law, with a flat decay of alpha = 0.5 +/- 0.3 until around the end of the first orbit of data. At this point, the decay steepens to 1.6 +0.9/-0.3. The afterglow is already faint by the end of the third orbit. A spectrum extracted from the first orbit of data can be modelled with an absorbed power-law, with Gamma = 2.05 +0.71/-0.64 and NH = (6.2 +5.4/-3.6)x10^21 cm^-2, in excess of the Galactic column in this direction of 1.53x10^21 cm^-2. The observed (unabsorbed) flux over this time interval (75-800 s post-trigger) is 5.7x10^-12 (1.0x10^-11) erg cm^-2 s^-1. If the light-curve continues to decay with alpha ~ 1.6, the count rate 24 hours after the burst is estimated to be 3.3x10^-5 count s^-1, which corresponds to an observed flux of 2x10^-15 erg cm^-2 s^-1. This is an official product of the Swift-XRT team.