TITLE: GCN CIRCULAR NUMBER: 13442 SUBJECT: GRB 120711A: Swift-XRT observations DATE: 12/07/11 13:00:00 GMT FROM: Andy Beardmore at U Leicester A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team: We have analysed 657 s of XRT data for the INTEGRAL-detected burst: GRB 120711A (Gotz et al. GCN Circ. 13434), from 8.3 ks to 20.0 ks after the INTEGRAL trigger. The data comprise 269 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. An X-ray source is detected within the INTEGRAL error circle. Using 336 s of PC mode data and 1 UVOT images, we find an enhanced XRT position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 94.67830, -70.99905 which is equivalent to: RA (J2000): 06h 18m 42.79s Dec(J2000): -70d 59' 56.6" with an uncertainty of 1.7 arcsec (radius, 90% confidence). This position is 29 arcsec from the INTEGRAL position and 0.3 arcsec from the Skynet/PROMPT position (LaCluyze et al. GCN Circ. 13430). The light curve can be modelled with a power-law decay with a decay index of alpha=1.59 (+0.16, -0.15). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.15 (+/-0.11). The best-fitting absorption column is 3.6 (+/-0.4) x 10^21 cm^-2, in excess of the Galactic value of 7.9 x 10^20 cm^-2 (Kalberla et al. 2005). The PC mode spectrum has a photon index of 1.80 (+0.25, -0.23) and a best-fitting absorption column of 2.4 (+0.9, -0.8) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.5 x 10^-11 (6.2 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 2.4 (+0.9, -0.8) x 10^21 cm^-2 Galactic foreground: 7.9 x 10^20 cm^-2 Excess significance: 3.2 sigma Photon index: 1.80 (+0.25, -0.23) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00020223. This circular is an official product of the Swift-XRT team.