TITLE: GCN CIRCULAR NUMBER: 42645 SUBJECT: GRB 251111A: Swift-XRT observations DATE: 25/11/11 14:02:01 GMT FROM: Phil Evans at U of Leicester <pae9@star.le.ac.uk> P.A. Evans (U. Leicester), J.A. Kennea (PSU), E. Ambrosi (INAF-IASFPA) , A.P. Beardmore (U. Leicester), M.G. Bernardini (INAF-OAB), R. Brivio (INAF-OAB), D.N. Burrows (PSU), S. Campana (INAF-OAB), M. Capalbi (INAF-OAR), A. D'Ai (INAF-IASFPA), P. D'Avanzo (INAF-OAB), V. D'Elia (SSDC & INAF-OAR), S. Dichiara (PSU), M. Ferro (INAF-OAB), A. Melandri (INAF-OAR), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), M. Perri (SSDC & INAF-OAR), C. Salvaggio (INAF-OAB), T. Sbarrato (INAF-OAB), B. Sbarufatti (INAF-OAB), M.A. Williams (PSU) report on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the SVOM/ECLAIRs-detected source GRB 251111A, collecting 288 s of Photon Counting (PC) mode data between T0+7.4 ks and T0+7.8 ks after the trigger. We have detected 1 source. This has been automatically classified as an uncatalogued X-ray source. Uncatalogued X-ray sources -------------------------- Source 1 (SWIFT J020926.8+051342): ================================== RA (J2000.0): 32.3618 = 02 09 26.83 Dec (J2000.0): +5.2284 = +05 13 42.2 Error: 5.7 (arcsec, radius, 90% confidence). Detect flag: GOOD Distance: 2.0 arcmin from the SVOM/ECLAIRs position. Mean rate: 0.0264 [+0.0127, -0.0096] ct s^-1 Mean flux: (7.2 [+3.5, -2.6])e-13 erg cm^-2 s^-1 Peak rate: 0.0264 [+0.0127, -0.0096] ct s^-1 Peak flux: (7.2 [+3.5, -2.6])e-13 erg cm^-2 s^-1 ECF: 2.73e-11 erg cm^-2 ct^-1 assuming NH=5.07e+20 cm^-2, gamma=2.63 determined from a spectral fit. XMM UL: 2.6e-12 erg cm^-2 s^-1, (0.3-10 keV) so the source is not above this 3-sigma upper limit. There is no evidence for fading. The XRT position is consistent the optical counterpart reported by the SVOM/COLIBRÍ (FM-GFT; López-Cámara et al., GCN Circ. 42638), LCO 1m (Wu et al., GCN Circ. 42639) and SVOM/VT (Wu et al., GCN 42641) telescopes, as well as the Einstein Probe FXT X-ray detection (Cheng et al. 42643). All fluxes are 0.3-10 keV, observed. For all flux conversions and comparisons with catalogues and upper limits from other missions, we assumed a power-law spectrum with NH=3x10^20 cm^-2 and photon index (Gamma)=1.7 unless otherwise stated. The results of the XRT-team automatic analysis of the XRT observations, including a position-specific upper limit calculator, are available at https://www.swift.ac.uk/SVOM/SVOM_FIELD00049. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/42645. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...