//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31182 SUBJECT: GRB 211207A: Swift detection of a burst with an optical counterpart DATE: 21/12/07 21:04:39 GMT FROM: David Palmer at LANL E. Ambrosi (INAF-IASFPA), V. D'Elia (SSDC & INAF-OAR), S. Dichiara (PSU), J.D. Gropp (PSU), J. A. Kennea (PSU), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), T. M. Parsotan (GSFC/UMBC/CRESSTII) and B. Sbarufatti (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 20:52:56 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 211207A (trigger=1088376). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 149.625, -24.352 which is RA(J2000) = 09h 58m 30s Dec(J2000) = -24d 21' 05" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of about 4 sec. The peak count rate was ~1500 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 20:54:17.2 UT, 80.5 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 149.62449, -24.35970 which is equivalent to: RA(J2000) = 09h 58m 29.88s Dec(J2000) = -24d 21' 34.9" with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 27 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 https://www.swift.ac.uk/sper. We cannot determine whether the source is fading at the present time. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (4.94 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 3.1 (+3.50/-2.89) x 10^21 cm^-2 (90% confidence). UVOT took a finding chart exposure of 150 seconds with the White filter starting 84 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at RA(J2000) = 09:58:29.78 = 149.62408 DEC(J2000) = -24:21:31.1 = -24.35863 with a 90%-confidence error radius of about 0.62 arc sec. This position is 3.5 arc sec. from the center of the XRT error circle. The estimated magnitude is 17.45 with a 1-sigma error of about 0.14. No correction has been made for the expected extinction corresponding to E(B-V) of 0.050. Burst Advocate for this burst is E. Ambrosi (elena.ambrosi AT inaf.it). 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: 31183 SUBJECT: Swift GRB 211207A: Global MASTER-Net observations report DATE: 21/12/07 22:18:25 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, G.Antipov, D.Zimnukhov, V.Senik, T.Pogrosheva, E.Minkina, A.Chasovnikov, V.Topolev, V.Grinshpun, D.Kuvshinov, D. Cheryasov (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O.A. Gres, N.M. Budnev (Irkutsk State University, API), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational State University) MASTER-Kislovodsk robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) was pointed to the Swift GRB 211207A ( E. Ambrosi et al., GCN 31182) errorbox 4112 sec after notice time and 4128 sec after trigger time at 2021-12-07 22:01:45 UT, with upper limit up to 15.3 mag. The observations began at zenith distance = 87 deg. The sun altitude is -66.2 deg. The galactic latitude b = 24 deg., longitude l = 261 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1807266 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 4219 | MASTER-Kislovodsk | C | 180 | 14.6 | 4219 | MASTER-Kislovodsk | C | 180 | 14.3 | 4419 | MASTER-Kislovodsk | C | 180 | 14.5 | 4419 | MASTER-Kislovodsk | C | 180 | 14.2 | 4619 | MASTER-Kislovodsk | C | 180 | 14.8 | 4619 | MASTER-Kislovodsk | C | 180 | 14.4 | 4819 | MASTER-Kislovodsk | C | 180 | 15.3 | 4819 | MASTER-Kislovodsk | C | 180 | 14.7 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31184 SUBJECT: GRB 211207A: Enhanced Swift-XRT position DATE: 21/12/08 00:01:26 GMT FROM: Phil Evans at U of Leicester J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team. Using 1514 s of XRT Photon Counting mode data and 1 UVOT images for GRB 211207A, 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 = 149.62381, -24.35968 which is equivalent to: RA (J2000): 09h 58m 29.71s Dec (J2000): -24d 21' 34.8" with an uncertainty of 2.3 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: 31185 SUBJECT: GRB 211207A: Swift-XRT refined Analysis DATE: 21/12/08 10:17:20 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), M.G. Bernardini (INAF-OAB), M. Capalbi (INAF-IASFPA), B. Sbarufatti (PSU), D.N. Burrows (PSU), J. D. Gropp (PSU) and E. Ambrosi report on behalf of the Swift-XRT team: We have analysed 6.3 ks of XRT data for GRB 211207A (Ambrosi et al. GCN Circ. 31182), from 87 s to 39.7 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN Circ. 31184). The light curve can be modelled with a power-law decay with a decay index of alpha=0.92 (+0.08, -0.07). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.08 (+0.29, -0.27). The best-fitting absorption column is 1.7 (+0.9, -0.8) x 10^21 cm^-2, in excess of the Galactic value of 4.9 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 3.3 x 10^-11 (4.6 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.7 (+0.9, -0.8) x 10^21 cm^-2 Galactic foreground: 4.9 x 10^20 cm^-2 Excess significance: 2.7 sigma Photon index: 2.08 (+0.29, -0.27) If the light curve continues to decay with a power-law decay index of 0.92, the count rate at T+24 hours will be 1.9 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 6.3 x 10^-14 (8.7 x 10^-14) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01088376. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31188 SUBJECT: GRB 211207A: VLT/X-shooter redshift DATE: 21/12/08 14:25:11 GMT FROM: Benjamin Schneider at CEA B. Schneider (CEA Paris-Saclay), L. Izzo (DARK/NBI), D. B. Malesani (Univ. Radboud and DAWN/NBI), J. P. U. Fynbo (DAWN/NBI), K. Wiersema (Univ. Lancaster), V. D’Elia (ASI/SSDC, INAF/OAR), K. E. Heintz (Univ. Iceland and DAWN/NBI), report on behalf of the Stargate collaboration: We observed the afterglow of GRB 211207A (Ambrosi et al., GCN 31182) using the ESO VLT UT3 (Melipal) equipped with the X-shooter spectrograph. Our spectra cover the wavelength range 3000-21000 AA, and consist of 4 exposures of 1200 s each. The observation mid time was 2021 Dec 8.288 UT (10.04 hr after the GRB). In a 60 s image taken with the acquisition camera on Dec 8.249 UT, we detect the optical afterglow, for which we measure an AB magnitude r = 22.16 +/- 0.05 mag (calibrated against two nearby stars from the Pan-STARRS catalog). We clearly detect continuum over the wavelength range 3400 - 18000 AA. A trough is visible around 3960 AA, which we identify as due to H I. From detection of multiple absorption features, which we interpret as due to Si II, O I, C II, Fe II, Si IV, C IV, Al II, Mg II, we infer a redshift z = 2.272. An emission line is also detected at 16390 AA, which we interpret as due to [O III] from the GRB host galaxy. We acknowledge excellent support from the ESO observing staff in Paranal, in particular Joe Anderson, Zahed Wahhaj and Rob van Holstein. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31189 SUBJECT: GRB 211207A: Swift-BAT refined analysis DATE: 21/12/08 17:51:09 GMT FROM: Tyler Parsotan at UMBC/GSFC/CRESST II T. Sakamoto (AGU), S. D. Barthelmy (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC/UMBC), M. Stamatikos (OSU), (i.e. the Swift-BAT team): Using the data set from T-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 211207A (trigger #1088376) (Ambrosi et al., GCN 31182). The BAT ground-calculated position is RA, Dec = 149.601, -24.360 deg which is RA(J2000) = 09h 58m 24.1s Dec(J2000) = -24d 21' 37.3" with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 62%. The BAT light curve showed a complex structure with a duration of about 4 sec. T90 (15-350 keV) is 3.73 +- 0.87 sec (estimated error including systematics). The time-averaged spectrum from T-1.30 to T+2.97 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.72 +- 0.30. The fluence in the 15-150 keV band is 1.9 +- 0.4 x 10^-07 erg/cm2. The 1-sec peak photon flux measured from T-0.15 sec in the 15-150 keV band is 0.9 +- 0.2 ph/cm2/sec. 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/1088376/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31204 SUBJECT: GRB 211207A: Swift/UVOT Detection DATE: 21/12/11 16:03:37 GMT FROM: Mike Siegel at PSU/Swift MOC M. H. Siegel (PSU) and Ambrosi (INAF-IASFPA) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 211207A 85 s after the BAT trigger (Ambrosi et al., GCN Circ. 31182). A source consistent with the XRT position (Osborne et al. GCN Circ. 31184) is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 09:58:29.79 = 149.62412 (deg.) Dec (J2000) = -24:21:31.3 = -24.35869 (deg.) with an estimated uncertainty of 0.43 arc sec. (radius, 90% confidence). Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white 85 234 147 17.52 +/- 0.04 v 627 1595 117 >18.5 b 553 743 36 19.08 +/- 0.31 u 297 546 246 18.15 +/- 0.09 w1 677 1470 97 >18.7 m2 652 1272 39 >18.7 w2 776 1570 78 >19.0 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.050 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31290 SUBJECT: Fermi GBM Sub-Threshold Detection of GRB 211207A DATE: 21/12/23 15:03:48 GMT FROM: Cori Fletcher at USRA C. Fletcher (USRA) reports on behalf of the Fermi-GBM Team: Swift-BAT detected GRB 211207A at 20:52:56 UT (GCN 31182). There was no Fermi-GBM onboard trigger around the event. An automated, blind search for short gamma-ray bursts below the onboard triggering threshold in Fermi-GBM identified no counterparts. The GBM targeted search [1], the most sensitive, coherent search for GRB-like signals identified a transient most significantly on the 2.048 s timescale, with a false alarm rate of 3.2e-05 Hz and a location consistent with the Swift-BAT event, using the standard search protocol with a S/N of 8. The GBM targeted search event was found with the highest significance with a "soft" spectrum (Band function with Epeak = 70 keV, alpha = -1.9, beta = -3.7) for a GRB. [1] Goldstein et al. 2019 arXiv:1903.12597