//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20087 SUBJECT: GRB 161022A: Swift detection of a burst DATE: 16/10/22 03:03:37 GMT FROM: Scott Barthelmy at NASA/GSFC M. Stamatikos (OSU/NASA/GSFC), S. D. Barthelmy (GSFC), J. A. Kennea (PSU), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL) and T. N. Ukwatta (LANL) report on behalf of the Swift Team: At 02:43:40 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 161022A (trigger=718655). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 128.967, +54.365 which is RA(J2000) = 08h 35m 52s Dec(J2000) = +54d 21' 54" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a single peak with a duration of about 20 sec. The peak count rate was ~1200 counts/sec (15-350 keV), at ~2 sec after the trigger. The XRT began observing the field at 02:45:53.4 UT, 133.3 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 129.00074, 54.34876 which is equivalent to: RA(J2000) = 08h 36m 00.18s Dec(J2000) = +54d 20' 55.5" with an uncertainty of 3.5 arcseconds (radius, 90% containment). This location is 91 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. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (4.13 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 1.2 (+1.30/-1.19) x 10^21 cm^-2 (90% confidence). No UVOT data are available at this time. Burst Advocate for this burst is M. Stamatikos (Michael.Stamatikos-1 AT nasa.gov). 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/too.html.) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20088 SUBJECT: GRB 161022A: Prompt enhanced Swift-XRT position DATE: 16/10/22 03:20:24 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 161022A, we find an enhanced XRT position of the afterglow: RA, Dec: 129.0018, 54.3490 which is equivalent to: RA (J2000) = 08 36 00.44 Dec (J2000) = +54 20 56.3 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/718655. 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: 20089 SUBJECT: GRB 161022A: TAROT Calern observatory optical observations DATE: 16/10/22 08:01:15 GMT FROM: Alain Klotz at IRAP-CNRS-OMP Klotz A., Turpin D., Atteia J.L. (CNRS-OMP-IRAP), Boer, M., Laugier, R. (CNRS-ARTEMIS), Gendre B. (UVI - Etelman Obs.) report: We imaged the field of GRB 161022A detected by SWIFT (trigger 718655) with the TAROT robotic telescope (D=25cm) located at the Calern observatory, France. The observations started 71s after the GRB trigger (17s after the notice). The elevation of the field increased from 56 degrees above horizon and weather conditions were excellents. The first image is trailed with a duration of 60.0s (see the description in Klotz et al., 2006, A&A 451, L39). We do not detect any OT with a limiting magnitude of: t0+71.2s to t0+131.2s : Rlim = 17.4 The second image is 30.0s exposure in tracking mode: t0+146.3s to t0+176.3s : Rlim = 18.5 We co-added a series of exposures: t0+146.3s to t0+442.9s : Rlim = 19.0 No more OT detection until t0+6800s at Rlim = 19.0. Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20090 SUBJECT: GRB 161022A: LT observations DATE: 16/10/22 09:04:32 GMT FROM: Cristiano Guidorzi at Ferrara U,Italy C. Guidorzi (U. Ferrara), C.G. Mundell (U. Bath), S. Kobayashi, I.A. Steele (LJMU), A. Gomboc (U. Nova Gorica) on behalf of a large collaboration report: The 2-m Liverpool Telescope began observing Swift GRB161022A (Stamatikos et al., GCN 20087) with the RINGO3 polarimeter on October 22, 02:46:59 UT (199 s since trigger). Within the prompt enhanced XRT error circle (Evans et al. GCN 20088) we found nothing brighter than 20.5 mag in the SDSS-R filter at a mid time of 35 minutes post burst. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20092 SUBJECT: GRB 161022A: Swift-XRT refined Analysis DATE: 16/10/22 12:26:37 GMT FROM: Phil Evans at U of Leicester V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), B. Mingo (U. Leicester), A. Melandri (INAF-OAB) and M. Stamatikos report on behalf of the Swift-XRT team: We have analysed 8.7 ks of XRT data for GRB 161022A (Stamatikos et al. GCN Circ. 20087), from 118 s to 22.5 ks after the BAT trigger. The data comprise 7 s in Windowed Timing (WT) mode (taken while Swift was slewing), with the remainder in Photon Counting (PC) mode. The best available XRT position (using the promptly downlinked event data, the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue) is RA, Dec = 129.0017, 54.3486 which is equivalent to: RA (J2000): 08 36 00.40 Dec(J2000): +54 20 55.0 with an uncertainty of 2.0 arcsec (radius, 90% confidence). The light curve can be modelled with a power-law decay with a decay index of alpha=1.46 (+0.13, -0.11). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.70 (+0.16, -0.07). The best-fitting absorption column is consistent with the Galactic value of 4.1 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 3.8 x 10^-11 (4.0 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 4.1 (+/-2.0) x 10^20 cm^-2 Galactic foreground: 4.1 x 10^20 cm^-2 Excess significance: <1.6 sigma Photon index: 1.70 (+0.16, -0.07) If the light curve continues to decay with a power-law decay index of 1.46, the count rate at T+24 hours will be 1.5 x 10^-4 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.6 x 10^-15 (5.9 x 10^-15) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00718655. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20094 SUBJECT: GRB 161022A: Enhanced Swift-XRT position DATE: 16/10/22 14:29:41 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 1530 s of XRT Photon Counting mode data and 2 UVOT images for GRB 161022A, 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 = 129.00148, +54.34828 which is equivalent to: RA (J2000): 08h 36m 0.35s Dec (J2000): +54d 20' 53.8" with an uncertainty of 1.4 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: 20095 SUBJECT: GRB 161022A: NOT optical observations DATE: 16/10/22 15:40:02 GMT FROM: Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst D. Malesani (DARK/NBI and DTU Space) and J. Prieto-Arranz (IAC) report on behalf of a larger collaboration: We observed the field of GRB 161022A (Stamatikos et al., GCN 20087) using the Nordic Optical Telescope (NOT) equipped with the AlFOSC imaging camera. Observations started on 2016 Oct 22.161 UT, 68.5 min after the GRB, and consisted of 2x300 s exposures in the SDSS r band. Observations were affected by adverse weather conditions. Within or in the proximity of the XRT error circle (Evans, GCN 20088), at a mid time of 73.9 min after the GRB trigger, we detect no new sources down to a limiting magnitude r > 22 (AB), calibrated against nearby SDSS stars. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20096 SUBJECT: GRB 161022A: Fermi GBM observation DATE: 16/10/22 16:33:18 GMT FROM: Oliver Roberts at UCD/Fermi O.J. Roberts (UCD) reports on behalf of the Fermi GBM Team: At 02:43:45.92 UT on October 22nd, 2016, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 161022A (trigger 498797029/161022114), which was also detected by Swift (Stamatikos et al., GCN 20087). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight is 131 degrees. The GBM light curve shows a weak, FRED-like peak with a duration (T90) of about 19 s (50-300 keV). The time-averaged spectrum from T0-6.1 s to T0+11.3 s is adequately fit by a power law function with an exponential high-energy cutoff. The power law index is -0.59 +/- 0.37 and the cutoff energy, parameterized as Epeak, is 155.7 +/- 33.2 keV The event fluence (10-1000 keV) in this time interval is (1.65 +/- 0.24)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0-1.3 s in the 10-1000keV band is 2.5 +/- 0.4 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20097 SUBJECT: GRB 161022A: Swift/UVOT Upper Limits DATE: 16/10/22 16:48:34 GMT FROM: Lea Hagen at PSU L. M. Z. Hagen (PSU) and M. Stamatikos (OSU/NASA/GSFC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 161022A 137 s after the BAT trigger (Stamatikos et al., GCN Circ. 20087). No optical afterglow consistent with the XRT position (Evans et al. GCN Circ. 20094) 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 early exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white 137 1544 539 >21.25 u 296 1668 333 >19.90 b 551 1692 99 >19.27 v 627 1421 97 >18.34 uvw1 676 1644 116 >18.86 uvm2 824 1272 38 >17.99 uvw2 602 1570 116 >19.10 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.04 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20098 SUBJECT: GRB 161022A: RATIR Optical and NIR Observations DATE: 16/10/22 17:26:16 GMT FROM: Alan M. Watson at Instituto de Astronomia UNAM Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy (UMD) report: We observed the field of GRB 161022A (Stamatikos et al., GCN Circ. 20087) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir from 2016/10 22.37 to 2016/10 22.53 UTC (6.23 to 9.89 hours after the BAT trigger), obtaining a total of 2.49 hours exposure in the r and i bands and 1.04 hours exposure in the Z, Y, J, and H bands. For a source within the Swift-XRT error circle (D'Elia et al., GCN Circ. 20092), in comparison with the SDSS DR9 and 2MASS catalogs, we obtain the following 3-sigma upper limits: r > 24.24 i > 24.04 Z > 22.96 Y > 22.50 J > 22.18 H > 21.87 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20100 SUBJECT: GRB 161022A: Swift-BAT refined analysis DATE: 16/10/22 22:02:21 GMT FROM: Scott Barthelmy at NASA/GSFC H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-239 to T+737 sec from recent telemetry downlinks, we report further analysis of BAT GRB 161022A (trigger #718655) (Stamatikos, et al., GCN Circ. 20087). The BAT ground-calculated position is RA, Dec = 128.988, 54.366 deg, which is RA(J2000) = 08h 35m 57.2s Dec(J2000) = +54d 21' 57.8" with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 14%. The mask-weighted light curve shows a few overlapping peaks starting at ~T-1 sec, peaking at ~T+2 sec, an ending at ~T+15 sec. T90 (15-350 keV) is 7.3 +- 1.0 sec (estimated error including systematics). The time-averaged spectrum from T+0.53 to T+8.24 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.14 +- 0.21. The fluence in the 15-150 keV band is 7.5 +- 1.0 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+2.13 sec in the 15-150 keV band is 1.6 +- 0.4 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/718655/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20143 SUBJECT: GRB 161022A: 15 GHz upper limits from AMI DATE: 16/11/07 19:29:05 GMT FROM: Kunal Mooley at Oxford U K. P. Mooley (Hintze Fellow, Oxford), T. D. Staley, R. P. Fender (Oxford), G. E. Anderson (Curtin), T. Cantwell (Manchester), D. Titterington, S. H. Carey, J. Hickish, Y. C. Perrott, N. Razavi-Ghods, P. Scott (Cambridge), K. Grainge, A. Scaife (Manchester) The AMI Large Array robotically triggered on the Swift alert for GRB 161022A (Stamatikos et al., GCN 20087) as part of the 4pisky program, and subsequent follow up observations were obtained up to 10 days post-burst. Our observations at 15 GHz on 2016 Oct 22.15, Oct 23.26, Oct 26.22 and Oct 29.31 (UT) do not reveal any radio source at the XRT location (Evans et al., GCN 20094), with 3sigma upper limits of 135 uJy, 93 uJy, 105 uJy and 105 uJy respectively. We thank the AMI staff for scheduling these observations. The AMI-GRB database is a log of all GRB follow up observations with the AMI, and is available at http://4pisky.org/ami-grb/.