//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18874 SUBJECT: GRB 160117A: Swift detection of a burst DATE: 16/01/17 10:25:30 GMT FROM: David Palmer at LANL C. B. Markwardt (NASA/GSFC), K. L. Page (U Leicester) and D. M. Palmer (LANL) report on behalf of the Swift Team: At 10:13:39 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 160117A (trigger=670793). Swift could not slew to the burst location due to an observing constraint. The BAT on-board calculated location is RA, Dec 20.408, -0.627 which is RA(J2000) = 01h 21m 38s Dec(J2000) = -00d 37' 37" 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 30 sec. The peak count rate was ~1300 counts/sec (15-350 keV), at ~6 sec after the trigger. Due to a Moon observing constraint, Swift cannot slew to the BAT position until 00:56 UT on 2016 January 18. There will thus be no XRT or UVOT data for this trigger before this time. Burst Advocate for this burst is C. B. Markwardt (Craig.Markwardt 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: 18882 SUBJECT: GRB 160117A: Swift-BAT refined analysis DATE: 16/01/17 23:00:29 GMT FROM: Craig Markwardt at NASA/GSFC D. M. Palmer, S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), 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-173 to T+1029 sec from the recent telemetry downlink, we report further analysis of BAT GRB 160117A (trigger #670793) (Markwardt, et al., GCN Circ. 18874). The BAT ground-calculated position is RA, Dec = 20.367, -0.677 deg which is RA(J2000) = 01h 21m 28.0s Dec(J2000) = -00d 40' 37.8" with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 60%. The mask-weighted light curve consists of a faint precursor from about T-70 sec to T+30 sec, followed by brighter double-peaked structure from about T+30 sec to T+115 sec. T90 (15-350 keV) is 118.58 +- 20.46 sec (estimated error including systematics). The time-averaged spectrum from T-46 to T+109 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.14 +- 0.11. The fluence in the 15-150 keV band is 3.1 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+76 sec in the 15-150 keV band is 1.4 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level. Please note that GRB 160117B was incorrectly marked with the same trigger number as GRB 160117A in Sonbas et al. 2016 (GCN Circ. 18875). The correct trigger number for 160117A is above. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/670793/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18888 SUBJECT: GRB 160117A: Swift-XRT observations DATE: 16/01/18 10:56:39 GMT FROM: Kim Page at U.of Leicester A. Maselli (INAF-IASFPA), A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), T.G.R. Roegiers (PSU), S.L. Gibson (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester) and D. M. Palmer report on behalf of the Swift-XRT team: We have analysed 4.6 ks of Photon Counting (PC) mode XRT data for the Swift/BAT-detected burst GRB 160117A (Palmer et al. GCN Circ. 18882), collected between T0+68.7 ks and T0+76.8 ks. One uncatalogued X-ray source has been detected inside or close to the Swift/BAT error region, 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): 20.3683 = 01:21:28.40 Dec (J2000.0): -0.6542 = -00:39:15.3 Error: 3.9 arcsec (radius, 90% conf.) Count-rate: 0.0142 +/- 0.0020 ct s^-1 Flux: (4.04 +/- 0.58)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 http://www.swift.ac.uk/ToO_GRBs/00670793. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18892 SUBJECT: GRB 160117A: Swift/UVOT Upper Limits DATE: 16/01/19 02:00:12 GMT FROM: Lea Hagen at PSU L. M. Z. Hagen (PSU) and C. B. Markwardt (NASA/GSFC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 160117A 68.7 ks after the BAT trigger (Markwardt et al. GCN Circ. 18874). No optical afterglow consistent with the XRT position of Source 1 (Maselli et al. GCN Circ. 18888) 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 exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag v 75251 76158 885 >19.75 u 70499 70799 295 >19.80 w1 69593 80420 1226 >20.52 m2 68687 76854 1565 >20.90 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: 18910 SUBJECT: GRB 160117A: Swift-XRT afterglow detection DATE: 16/01/21 07:19:22 GMT FROM: Kim Page at U.of Leicester A. Maselli (INAF-IASFPA), A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), T.G.R. Roegiers (PSU), S.L. Gibson (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester) and D. M. Palmer report on behalf of the Swift-XRT team: Swift-XRT has conducted further observations of the field of the Swift/BAT-detected burst GRB 160117A (Palmer et al. GCN Circ. 18882). The observations now extend from T0+68.7 ks to T0+304.5 ks. The source previously reported by Maselli et al. (GCN Circ. 18888), "Source 1", is fading with 3-sigma significance, and is therefore likely the GRB afterglow. The position of this source is RA, Dec=20.3683, -0.6541 which is equivalent to: RA (J2000): 01:21:28.39 Dec(J2000): -00:39:14.7 with an uncertainty of 3.8 arcsec (radius, 90% confidence). This position is 65 arcsec from the Swift/BAT position. The light curve can be modelled with a power-law decay with a decay index of alpha=1.1 (+0.5, -0.4). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 3.7 (+0.9, -0.6). The best-fitting absorption column is 1.2 (+0.6, -0.4) x 10^22 cm^-2, in excess of the Galactic value of 4.4 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 2.6 x 10^-11 (3.7 x 10^-10) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.2 (+0.6, -0.4) x 10^22 cm^-2 Galactic foreground: 4.4 x 10^20 cm^-2 Excess significance: 5.2 sigma Photon index: 3.7 (+0.9, -0.6) The results of the XRT-team automatic analysis of the likely afterglow are at http://www.swift.ac.uk/ToO_GRBs/00670793/index_1.php. The results of the full analysis of the XRT observations are available at http://www.swift.ac.uk/ToO_GRBs/00670793. This circular is an official product of the Swift-XRT team.