TITLE: GCN CIRCULAR NUMBER: 35319 SUBJECT: GRB 231210B: Swift-XRT refined Analysis DATE: 23/12/11 10:23:58 GMT FROM: Phil Evans at U of Leicester <pae9@star.le.ac.uk> J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), M. Capalbi (INAF-IASFPA), M. Perri (SSDC & INAF-OAR), V. D'Elia (SSDC & INAF-OAR), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), D.N. Burrows (PSU) and P.A. Evans report on behalf of the Swift-XRT team: We have analysed 6.4 ks of XRT data for GRB 231210B, from 410 s to 35.6 ks after the BAT trigger. The data comprise 40 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The light curve can be modelled with a power-law decay with a decay index of alpha=1.32 (+0.05, -0.04). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.65 (+0.11, -0.10). The best-fitting absorption column is 5.3 (+7.7, -5.3) x 10^21 cm^-2, at a redshift of 3.13, in addition to the Galactic value of 4.1 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.0 x 10^-11 (4.3 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Galactic foreground: 4.1 x 10^20 cm^-2 Intrinsic column: 5.3 (+7.7, -5.3) x 10^21 cm^-2 at z=3.13 Photon index: 1.65 (+0.11, -0.10) If the light curve continues to decay with a power-law decay index of 1.32, the count rate at T+24 hours will be 4.5 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.8 x 10^-13 (1.9 x 10^-13) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01201696. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/35319. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...