TITLE: GCN CIRCULAR NUMBER: 43112 SUBJECT: GRB 251214B: Swift-XRT refined Analysis DATE: 25/12/15 09:28:13 GMT FROM: Phil Evans at U of Leicester <pae9@star.le.ac.uk> D.N. Burrows (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), R. Brivio (INAF-OAB), A. D'Ai (INAF-IASFPA), S. Campana (INAF-OAB), S. Lanava (PSU), S. Dichiara (PSU) and P.A. Evans report on behalf of the Swift-XRT team: We have analysed 5.9 ks of XRT data for GRB 251214B, from 46 s to 28.7 ks after the trigger. The data comprise 8 s in Windowed Timing (WT) mode (taken while Swift was slewing), with the remainder in Photon Counting (PC) mode. The light curve can be modelled with an initial power-law decay with an index of alpha=0.72 (+0.14, -0.17), followed by a break at T+418 s to an alpha of 1.33 (+0.10, -0.08). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.82 (+0.19, -0.18). The best-fitting absorption column is 1.6 (+0.7, -0.6) x 10^21 cm^-2, in excess of the Galactic value of 4.0 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 3.9 x 10^-11 (4.9 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.6 (+0.7, -0.6) x 10^21 cm^-2 Galactic foreground: 4.0 x 10^20 cm^-2 Excess significance: 3.5 sigma Photon index: 1.82 (+0.19, -0.18) If the light curve continues to decay with a power-law decay index of 1.33, the count rate at T+24 hours will be 1.6 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 6.3 x 10^-14 (7.8 x 10^-14) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at https://www.swift.ac.uk/xrt_products/01423875. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/43112. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...