//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26269 SUBJECT: GRB 191122A: Swift detection of a burst DATE: 19/11/22 13:45:34 GMT FROM: Boris Sbarufatti at PSU B. Sbarufatti (PSU), A. P. Beardmore (U Leicester), J.D. Gropp (PSU), J. A. Kennea (PSU), H. A. Krimm (NSF), N. P. M. Kuin (UCL-MSSL), S Laha (GSFC/UMBC/CRESST) and A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels Swift Observatory Team: At 13:32:56 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 191122A (trigger=938899). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 54.296, -32.176 which is RA(J2000) = 03h 37m 11s Dec(J2000) = -32d 10' 32" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single-peaked structure with a duration of about 50 sec. The peak count rate was ~1200 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 13:34:31.1 UT, 94.7 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source located at RA, Dec 54.26926, -32.18602 which is equivalent to: RA(J2000) = 03h 37m 04.62s Dec(J2000) = -32d 11' 09.7" with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 89 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper. No spectrum from the promptly downlinked event data is yet available to determine the column density. The initial flux in the 2.5 s image was 1.89e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 103 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.01. Burst Advocate for this burst is B. Sbarufatti (bxs60 AT psu.edu). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26270 SUBJECT: GRB 191122A: Prompt enhanced Swift-XRT position DATE: 19/11/22 14:05:22 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Using promptly downlinked XRT event data for GRB 191122A, we find an enhanced XRT position of the afterglow: RA, Dec: 54.2703, -32.1864 which is equivalent to: RA (J2000) = 03 37 04.86 Dec (J2000) = -32 11 10.9 with an uncertainty of 2.0 arcseconds (radius, 90% confidence). Analysis of the promptly available data is online at http://www.swift.ac.uk/sper/938899. Position enhancement is is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26271 SUBJECT: GRB 191122A: CHES Optical Observations DATE: 19/11/22 16:50:23 GMT FROM: Tianrui Sun at Purple Mountain Obs,CAS Tianrui Sun, Chen Zhang, Yiding Ping, Xuefeng Wu (PMO). We report the observations for the GRB191122A (B. Sbarufatti et al., GCN Circ 26269). We use the 80cm telescope of CHanging Event Survey at the YaoAn observation station(101.1811E, 25.528N) in Yunnan Province, China. Our observation starts at 13:48:57 UT and ends at 13:54:24 UT Nov 22, 2019, with five exposure 60 seconds in white filter. We do not detect any candidate sources in the combined image in the enhanced XRT position error region to a 5 sigma limit at 18.31 generated from G band magnitude in Gaia DR2 . //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26272 SUBJECT: GRB 191122A: Enhanced Swift-XRT position DATE: 19/11/22 21:05:05 GMT FROM: Phil Evans at U of Leicester P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team. Using 4899 s of XRT Photon Counting mode data and 11 UVOT images for GRB 191122A, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 54.26986, -32.18665 which is equivalent to: RA (J2000): 03h 37m 4.77s Dec (J2000): -32d 11' 11.9" with an uncertainty of 1.6 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26273 SUBJECT: GRB 191122A: BOOTES-4/MET optical limit DATE: 19/11/22 21:54:26 GMT FROM: Alberto J. Castro-Tirado at IAA-CSIC Y.-D. Hu, E. Fernandez-Garcia, A. J. Castro-Tirado (IAA-CSIC), C. Perez del Pulgar, A. Castellon, I. Carrasco (Univ. de Malaga),  S. Guziy (Univ. of Nikolaev) and D. Xiong, Y. Fan, X. Zhao, J. Bai, C. Wang, Y. Xin (Yunnan Nacional Astronomical Observatory) on behalf of a larger collaboration, report: Following the detection of GRB 191122A by Swift (Sbarufatti et al. GCNC 26269), the 0.6m BOOTES-4/MET robotic telescope at Lijiang Astronomical Observatory (China) started to gather images at 13:34 UT (~94s after trigger). No optical afterglow is found down to 20.3 mag (unfiltered images) at the enhaced Swift/XRT position (Evans et al. GCNC 26270), consistent with the non-detections by Swift/UVOT (Sbarufatti et al. GCNC 26269) and CHES (Sun et al. GCNC 26271). Observations are ongoing." We thank the staff at Lijiang Astronomical Observatory for their excellent support. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26274 SUBJECT: GRB 191122A: Swift-XRT refined Analysis DATE: 19/11/22 22:21:07 GMT FROM: Phil Evans at U of Leicester A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), J.A. Kennea (PSU), D.N. Burrows (PSU), J.P. Osborne (U. Leicester) and B. Sbarufatti report on behalf of the Swift-XRT team: We have analysed 8.8 ks of XRT data for GRB 191122A (Sbarufatti et al. GCN Circ. 26269), from 301 s to 23.9 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN Circ. 26270). The light curve can be modelled with a series of power-law decays. The initial decay index is alpha=0.97 (+0.26, -0.31). At T+746 s the decay steepens to an alpha of 1.94 (+0.26, -0.10) before breaking again at T+6109 s to a final decay with index alpha=-0.1 (+/-0.4). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.06 (+0.04, -0.03). The best-fitting absorption column is consistent with the Galactic value of 1.0 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.12 (+0.08, -0.07) and a best-fitting absorption column consistent with the Galactic value. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 5.6 x 10^-11 (5.6 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 10.0 (+15.8, -0.0) x 10^19 cm^-2 Galactic foreground: 1.0 x 10^20 cm^-2 Excess significance: <1.6 sigma Photon index: 1.12 (+0.08, -0.07) If the light curve continues to decay with a power-law decay index of -0.1, the count rate at T+24 hours will be 0.067 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.8 x 10^-12 (3.8 x 10^-12) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00938899. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26275 SUBJECT: GRB 191122A: Swift-BAT refined analysis DATE: 19/11/22 23:46:51 GMT FROM: Hans Krimm at NSF/NASA-GSFC H. A. Krimm (NSF), S. D. Barthelmy (GSFC), S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), B. Sbarufatti (PSU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 191122A (trigger #938899) (Sbarufatti, et al., GCN Circ. 26269). The BAT ground-calculated position is RA, Dec = 54.290, -32.176 deg which is RA(J2000) = 03h 37m 09.7s Dec(J2000) = -32d 10' 35.4" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 26%. The mask-weighted light curve shows a single FRED-shaped pulse rising from T-20 sec to T+0 sec, then decaying out to roughly T+250 sec. T90 (15-350 keV) is 153.3 +- 38.3 sec (estimated error including systematics). The time-averaged spectrum from -11.2 to 245.4 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 1.24 +- 0.28, and Epeak of 89.2 +- 41.9 keV (chi squared 69.11 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 6.6 +- 0.3 x 10^-6 erg/cm2 and the 1-sec peak flux measured from T+6.44 sec in the 15-150 keV band is 3.1 +- 0.4 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.67 +- 0.07 (chi squared 76.48 for 57 d.o.f.). All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/938899/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26277 SUBJECT: GRB 191122A: Swift/UVOT Upper Limits DATE: 19/11/23 01:05:16 GMT FROM: Paul Kuin at MSSL N. P. M. Kuin (UCL-MSSL) and B. Sbarufatti (PSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 191122A 104 s after the BAT trigger (Sbarufatti et al., GCN Circ. 26269). No optical afterglow consistent with the XRT position (Evans GCN Circ. 26270,26272) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 104 253 147 >21.1 u_FC 316 566 246 >20.4 white 104 11801 1305 >22.0 v 647 6097 432 >20.2 b 572 10938 1121 >21.9 u 316 6696 642 >20.5 w1 696 6508 413 >20.1 m2 846 6303 413 >21.2 w2 797 5893 413 >20.1 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.01 in the direction of the burst (Schlegel et al. 1998).