GCN Circular 5783
R. L. C. Starling, K. L. Page (U Leicester) and S. T. Holland (GSFC/USRA) report on behalf of the Swift XRT team: We have analysed the first 3 orbits of Swift XRT data obtained for GRB 061102 (trigger 236430, GCN 5776 Holland et al.). The data consist of 208 s of WT mode data beginning at 112s since BAT trigger and 2560s of subsequent PC mode data. Using the PC mode data we obtain a refined position of: RA(J2000) = 09 53 37.64 Dec(J2000) = -17 01 26.5 with an estimated uncertainty of 4.9 arcsec (90% containment) taking into account the new TELDEF files. This location is 1.8 arcsec from the initial XRT position (GCN Circ. 5776) and 98.7 arcsec from the ground-calculated BAT position (GCN Circ. 5777; Tueller et al.) The lightcurve shows a steep decay over the first 400s with a slope of alpha = 4.0+/-0.1. At ~400s the lightcurve breaks to a slope of alpha~1. The first orbit WT-mode spectrum can be well fitted with an absorbed power law with index Gamma = 3.6+/-0.2. The total column density required is 1.6E21 cm^-2 which exceeds the Galactic value of 5.0E20 cm^-2 (Dickey & Lockman 1990). The total flux in the 0.3-10 keV band is 1.2E-10 erg cm^-2 s^-1. All errors are quoted at the 90% confidence limit. From these data we predict a count rate of 3.3E-4 counts s^-1, corresponding to a flux of approximately 8E-15 erg cm^-2 s^-1 at T+24h. This circular is an official product of the Swift-XRT team.