//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31057 SUBJECT: GRB 211107B: Swift/BAT detection DATE: 21/11/08 22:11:57 GMT FROM: Aaron Tohuvavohu at U Toronto Swift/BAT did not successfully trigger on GRB 211107B (T0: 2021-11-07 17:27:10 UTC). Swift/BAT triggered in real-time onboard in the rates domain (trigger #1082818), but no strong source was found to be associated in the onboard imaging. This 'failed trigger' resulted in 10s of BAT TTE data being saved and sent to the ground. The duration of the burst, as seen by BAT, is ~15 seconds. In ground analysis of the available TTE data, we find the position of the burst with SNR 12.6 in the image domain. The BAT position is RA, Dec = 65.7949 -27.5524, which is: RA (J2000) 04h 23m 10.78s Dec (J2000) -27d 33' 8.6" with an estimated uncertainty of 2 arcminutes. XRT and UVOT follow-up has been requested. Results of follow-up observations will be reported in future circulars. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31061 SUBJECT: GRB 211107B: Swift ToO observations DATE: 21/11/09 02:59:25 GMT FROM: Phil Evans at U of Leicester P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a ToO observation of the Swift/BAT GRB 211107B. Automated analysis of the XRT data will be presented online at https://www.swift.ac.uk/ToO_GRBs/00021467 Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. These are not necessarily related to the Swift/BAT event. Any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration. Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8). This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31064 SUBJECT: GRB 211107B: Swift-XRT observations DATE: 21/11/09 16:34:27 GMT FROM: Phil Evans at U of Leicester A. D'Ai (INAF-IASFPA), D.N. Burrows (PSU), J. D. Gropp (PSU), J.A. Kennea (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A. Melandri (INAF-OAB), T. Sbarrato (INAF-OAB) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the Swift/BAT-detected burst GRB 211107B (Swift/BAT did not successfully trigger on GRB 211107B et al. GCN Circ. 31057), collecting 1.7 ks of Photon Counting (PC) mode data between T0+124.3 ks and T0+131.0 ks. One uncatalogued X-ray source has been detected consistent with being within 197 arcsec of the Swift/BAT position, it is below the RASS limit and shows no definitive signs of fading. Therefore, at the present time we cannot confirm this as the afterglow. Details of this source are given below: Source 1: RA (J2000.0): 65.80807 = 04:23:13.94 Dec (J2000.0): -27.56097 = -27:33:39.5 Error: 2.9 arcsec (radius, 90% conf. [Enhanced position]) Count-rate: 0.0220 +/- 0.0042 ct s^-1 Distance: 52 arcsec from Swift/BAT position. Flux: (5.15 +/- 0.98)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV) 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/ToO_GRBs/00021467. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31072 SUBJECT: GRB 211107B: Swift-XRT afterglow detection DATE: 21/11/10 11:36:34 GMT FROM: Phil Evans at U of Leicester A. D'Ai (INAF-IASFPA), D.N. Burrows (PSU), J. D. Gropp (PSU), J.A. Kennea (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A. Melandri (INAF-OAB), T. Sbarrato (INAF-OAB) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team: Swift-XRT has conducted further observations of the field of the Swift/BAT-detected burst GRB 211107B (Swift/BAT did not successfully trigger on GRB 211107B et al. GCN Circ. 31057). The observations now extend from T0+124.3 ks to T0+147.5 ks. The source previously reported by D'Ai et al. (GCN Circ. 31064), "Source 1", is fading with 1.8 sigma significance and thus is believed to be the GRB afterglow. Using 2958 s of PC mode data and 4 UVOT images, we find an enhanced XRT position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 65.80812, -27.56084 which is equivalent to: RA (J2000): 04h 23m 13.95s Dec(J2000): -27d 33' 39.0" with an uncertainty of 2.7 arcsec (radius, 90% confidence). This position is 51 arcsec from the Swift/BAT position. The light curve can be modelled with a power-law decay with a decay index of alpha=2.84 (+0.04, -2.67). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.5 (+0.9, -0.7). The best-fitting absorption column is 1.6 (+2.5, -1.2) x 10^21 cm^-2, consistent with the Galactic value of 4.3 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 2.7 x 10^-11 (4.5 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.6 (+2.5, -1.2) x 10^21 cm^-2 Galactic foreground: 4.3 x 10^20 cm^-2 Excess significance: <1.6 sigma Photon index: 2.5 (+0.9, -0.7) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00021467. The results of the full analysis of the XRT observations are available at https://www.swift.ac.uk/ToO_GRBs/00021467. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31086 SUBJECT: Konus-Wind detection of GRB 211107B DATE: 21/11/16 14:29:21 GMT FROM: Dmitry Svinkin at Ioffe Institute D. Svinkin, S. Golenetskii, D. Frederiks, M. Ulanov, A. Tsvetkova, A. Lysenko, A. Ridnaia, and T. Cline on behalf of the Konus-Wind team, report: The long-duration GRB 211107B (Swift-BAT detection: Tohuvavohu, GCN Circ. 31057) triggered Konus-Wind at T0=62836.647 s UT (17:27:16.647). The burst light curve shows the initial pulse, which starts at ~T0-3.7 s and has a total duration of ~24 s, followed by a weaker emission seen up to T0+205 s. The emission is seen up to ~1 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB211107_T62836/ As observed by Konus-Wind, the burst had a fluence of 8.95(-1.76,+1.88)x10^-6 erg/cm2, and a 64-ms peak flux, measured from T0-0.108 s, of 1.42(-0.68,+0.69)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The spectrum of the initial pulse (measured from T0 to T0+16.640 s) is best fit in the 20 keV - 2 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -0.88(-0.40,+0.47) and Ep = 152(-26,+41) keV (chi2 = 51/56 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -2.7 (chi2 = 51/55 dof). All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.