TITLE: GCN CIRCULAR NUMBER: 10960 SUBJECT: GRB 100713A: Swift XRT refined analysis DATE: 10/07/14 21:57:32 GMT FROM: Valerio D'Elia at ASDC V. D'Elia and G. Stratta (ASDC) report on behalf of the Swift-XRT team: We have analysed 6.0 ks of XRT data for GRB100713A (D'Elia et al. GCN Circ. 10952), from 6.23 to 52.3 ks after the INTEGRAL trigger (Mereghetti et al. GCN Circ. 10951). The data are entirely in Photon Counting (PC) mode. Using 1772 s of PC mode data and 2 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 = 255.20133, +28.39434 which is equivalent to: RA (J2000): 17 00 48.32 Dec(J2000): +28 23 39.6 with an uncertainty of 2.4 arcsec (radius, 90% confidence). The light curve can be modelled with a power-law decay with a decay index of alpha=1.25 (-0.8+0.9). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.50 (+0.78, -0.68). The best-fitting absorption column is 2.2 (+2.0, -1.3) x 10^21 cm^-2, in excess of the Galactic value of 5.0 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 3.5 x 10^-11 (7.6 x 10^-10) erg cm^-2 count^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00020143. This circular is an official product of the Swift-XRT team. ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program.