TITLE: GCN CIRCULAR NUMBER: 42119 SUBJECT: GRB 251005C: Swift-XRT refined Analysis DATE: 25/10/06 04:38:56 GMT FROM: Phil Evans at U of Leicester <pae9@star.le.ac.uk> J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), E. Ambrosi (INAF-IASFPA) , M. Capalbi (INAF-OAR), M. Perri (SSDC & INAF-OAR), S. Lanava (PSU), S. Dichiara (PSU), J.A. Kennea (PSU) and P.A. Evans report on behalf of the Swift-XRT team: We have analysed 7.6 ks of XRT data for GRB 251005C, from 129 s to 29.0 ks after the trigger. The data are entirely in Photon Counting (PC) mode. The light curve can be modelled with a power-law decay with a decay index of alpha=1.34 (+/-0.06). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.41 (+0.27, -0.25). The best-fitting absorption column is 7.1 (+2.8, -2.2) x 10^21 cm^-2, in excess of the Galactic value of 3.2 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 6.4 x 10^-11 (8.2 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 7.1 (+2.8, -2.2) x 10^21 cm^-2 Galactic foreground: 3.2 x 10^21 cm^-2 Excess significance: 2.9 sigma Photon index: 1.41 (+0.27, -0.25) If the light curve continues to decay with a power-law decay index of 1.34, the count rate at T+24 hours will be 4.2 x 10^-4 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.7 x 10^-14 (3.5 x 10^-14) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01401726. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/42119. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...