TITLE: GCN CIRCULAR NUMBER: 11627 SUBJECT: GRB 110201A: Swift-XRT refined Analysis DATE: 11/02/02 16:02:43 GMT FROM: Dirk Grupe at PSU/Swift-XRT D. Grupe and M. H. Siegel (PSU) report on behalf of the Swift-XRT team: We have analyzed 21 ks of XRT data for GRB 110201A (Siegel et al. GCN Circ. 11622), from 54 s to 83.0 ks after the BAT trigger. The data comprise 6 s in Windowed Timing (WT) mode (taken while Swift was slewing), with the remainder in Photon Counting (PC) mode. The light curve can be modeled with a broken power-law model with an initial decay slope of alpha-1 = 3.25 (+0.40, -0.66) and a break at Tbreak-1 = 380 (+120, -55) s. After this break the afterglow decays with a slope of alpha-2 = 1.03 (+0.12, -0.11). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.04 (+0.26, -0.29). The best-fitting absorption column is 3.1 (+0.5, -1.0) x 10^21 cm^-2, in excess of the Galactic value of 2.8 x 10^20 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.3 x 10^-11 (7.1 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 3.1 (+0.5, -1.0) x 10^21 cm^-2 Galactic foreground: 2.8 x 10^20 cm^-2 Excess significance: 5.3 sigma Photon index: 2.04 (+0.26, -0.29) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00444230. This circular is an official product of the Swift-XRT team.