TITLE: GCN CIRCULAR NUMBER: 6998 SUBJECT: GRB 071025: Swift-XRT Team refined analysis DATE: 07/10/25 14:14:05 GMT FROM: Claudio Pagani at PSU/Swift-XRT C. Pagani, D. N. Burrows, J. Racusin (PSU), P. Evans (U Leicester) report on behalf of the Swift-XRT Team: We have analysed the first three orbits of Swift-XRT data obtained for GRB 071025 (Pagani et al. GCN Circ. 6986), totalling 250 s of Windowed Timing (WT) data and 2.7 ks of Photon Counting (PC) data. Using 1189 seconds of overlapping XRT Photon Counting mode and UVOT V-band data, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 355.07142, 31.77857 which is equivalent to: RA (J2000): 23 40 17.14 Dec (J2000): +31 46 42.9 with an uncertainty of 1.7 arcsec (radius, 90% confidence). This is 7.1 arcsec from the refined XRT position (GCN Circ. 6990) and 0.7 arcsec from the optical afterglow found by ROTSE-III at McDonald Observatory (Rykoff et al., GCN Circ. 6987). The bright X-ray light-curve can be fitted by a broken power-law, with an initial steep decay index of 2.8 +/- 0.3 followed by a flatter decay index of 1.5 +/- 0.1 after a break at 260 +/- 20 seconds. The WT data (150-400 seconds) can be modelled as an absorbed power-law, with Gamma = 1.40 +/- 0.05 and a total absorbing column of NH = (0.9 +/- 0.1)e21 cm^-2, in excess of the Galactic value of 5.1e20 cm^-2. The 0.3-10 keV observed (unabsorbed) flux during this time is 2.0e-09(2.2e-09) erg cm^-2 s^-1. Assuming the source continues to decay with the same decay index of 1.5, we predict an XRT count rate of 7E-3 counts/s at T+24 hours, which corresponds to an observed flux of 4E-13 ergs cm^-2 s^-1. This circular is an official product of the Swift-XRT team.