GCN Circular 5641
E. Troja (INAF-IASFPa), K. L. Page (U. Leicester), D. Burrows (PSU) and L. M. Barbier (NASA/GSFC) report on behalf of the Swift/XRT team: We have analysed the first three orbits of Swift data of GRB 060927 (Barbier et al., GCN 5627). The XRT data set consists of 4 ks in Photon Counting mode (PC). We derived a refined XRT position of RA(J2000) = 21h 58m 12.2s Dec(J2000) = +05d 21' 52.2'' with an error of 6" (90% confidence, including boresight uncertainties). This position is within 1.8" of the initial XRT position, and 4.6" from the optical afterglow candidate, reported in GCN 5629 (Schaefer et al.). The lightcurve shows a break at 4 ks after the trigger. The decay before the break is 0.7 steepening to 1.4 at later times. The spectrum can be modelled with an absorbed power-law with a spectral index of 1.96+/-0.2 and a column density of 8+/-3 e20 cm^-2. The Galactic absorption in this direction is 5.2e20 cm^-2. The average unabsorbed flux for the first three orbits is 5.6e-12 ergs cm^-2 s^-1. At this decay rate we predict a count rate of 1.2e-3 cts/s at T+24h, corresponding to an unabsorbed flux of 7.2e-14 ergs cm^-2 s^-1. This circular is an official product of the Swift XRT Team.