TITLE: GCN CIRCULAR NUMBER: 42721 SUBJECT: GRB 251116C: Swift-XRT observations DATE: 25/11/17 15:30:14 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 251116C, collecting 1.7 ks of Photon Counting (PC) mode data between T0+10 ks and T0+26 ks after the trigger. We have detected 2 sources. These have been automatically classified as follows: * 0 likely counterparts * 0 candidate counterparts * 2 uncatalogued X-ray sources * 0 known X-ray sources Uncatalogued X-ray sources -------------------------- Source 1 (SWIFT J222122.5-102045): ================================== RA (J2000.0): 335.3441 = 22 21 22.58 Dec (J2000.0): -10.3459 = -10 20 45.2 Error: 6.9 (arcsec, radius, 90% confidence). Detect flag: GOOD Distance: 6.1 arcmin from the SVOM/ECLAIRs position. Mean rate: (7.3 [+3.1, -2.5])e-3 ct s^-1 Mean flux: (4.4 [+1.9, -1.5])e-13 erg cm^-2 s^-1 Peak rate: (7.3 [+3.1, -2.5])e-3 ct s^-1 Peak flux: (4.4 [+1.9, -1.5])e-13 erg cm^-2 s^-1 ECF: 6.06e-11 erg cm^-2 ct^-1 assuming NH=4.81e+20 cm^-2, gamma=0.94 determined from a spectral fit. XMM UL: 4.1e-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. There is 1 2MASS object within the source's 3-sigma error radius. Source 2 (SWIFT J222052.1-102849): ================================== RA (J2000.0): 335.2172 = 22 20 52.13 Dec (J2000.0): -10.4803 = -10 28 49.1 Error: 5.8 (arcsec, radius, 90% confidence). Detect flag: POOR Distance: 5.1 arcmin from the SVOM/ECLAIRs position. Mean rate: (-1.0 +/- -1.0)e0 ct s^-1 Mean flux: (-4.3 +/- -4.3)e-11 erg cm^-2 s^-1 Peak rate: (2.4 [+1.9, -1.3])e-3 ct s^-1 Peak flux: (1.03 [+0.80, -0.57])e-13 erg cm^-2 s^-1 XMM UL: 4.7e-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. 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_FIELD00051. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/42721. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...