//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17291 SUBJECT: GRB 150110B: Swift detection of a burst DATE: 15/01/10 22:32:50 GMT FROM: Scott Barthelmy at NASA/GSFC P. A. Evans (U Leicester), S. D. Barthelmy (GSFC), D. N. Burrows (PSU), N. Gehrels (NASA/GSFC), C. J. Mountford (U Leicester) and K. L. Page (U Leicester) report on behalf of the Swift Team: At 22:08:30 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 150110B (trigger=624606). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 289.360, +32.522, which is RA(J2000) = 19h 17m 26s Dec(J2000) = +32d 31' 20" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows multiple peaks structure with a duration of about 12 sec. The peak count rate was ~2500 counts/sec (15-350 keV), at ~2 sec after the trigger. The XRT began observing the field at 22:09:31.0 UT, 61.0 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source with an enhanced position: RA, Dec 289.3749, 32.5233 which is equivalent to: RA(J2000) = 19h 17m 29.97s Dec(J2000) = +32d 31' 24.0" with an uncertainty of 2.1 arcseconds (radius, 90% containment). This location is 45 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 (2.39 x 10^21 cm^-2, Willingale et al. 2013), with an excess column of 3 (+3.51/-2.95) x 10^21 cm^-2 (90% confidence). UVOT took a finding chart exposure of 150 seconds with the White filter starting 65 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 0.20. Burst Advocate for this burst is P. A. Evans (pae9 AT star.le.ac.uk). 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: 17294 SUBJECT: GRB 150110B: Enhanced Swift-XRT position DATE: 15/01/11 05:52:37 GMT FROM: Phil Evans at U of Leicester A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team. Using 3739 s of XRT Photon Counting mode data and 6 UVOT images for GRB 150110B, 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 = 289.37494, +32.52333 which is equivalent to: RA (J2000): 19h 17m 29.99s Dec (J2000): +32d 31' 24.0" 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: 17295 SUBJECT: GRB 150110B: Fermi GBM Detection DATE: 15/01/11 06:03:26 GMT FROM: Matthew Stanbro at UAH/Fermi Matthew Stanbro (UAH) report on behalf of the Fermi GBM Team: "At 22:08:31.91 UT on 10 January 2015, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 150110B (trigger 442620514 / 150110923) which was also detected by the Swift/BAT (Evans et al. 2015, GCN 17291) The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight is 22 degrees. The GBM light curve consists of 1 peak with a duration (T90) of about 2 s (50-300 keV). The time-averaged spectrum from T0-1.54 s to T0+1.54 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.98 +/- 0.22 and the cutoff energy, parameterized as Epeak, is 122.5 +/- 24.3 keV The event fluence (10-1000 keV) in this time interval is (5.30 +/- 0.61)E-07 erg/cm^2. The 1-sec peak photon flux measured starting from T0-0.06 s in the 8-1000 keV band is 2.33 +/- 0.21 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: 17296 SUBJECT: GRB 150110B: Swift/UVOT Upper Limits DATE: 15/01/11 06:47:06 GMT FROM: Paul Kuin at MSSL N. P. M. Kuin (UCL-MSSL) and P. A. Evans (U Leicester) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 150110B 65 s after the BAT trigger (Evans et al., GCN Circ. 17291). No optical afterglow consistent with the XRT position (Beardmore et al., GCN Circ. 17294) 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 65 215 147 >21.0 u_FC 277 527 246 >20.3 white 65 12665 1414 >21.7 v 607 6471 452 >19.6 b 532 11960 1140 >21.5 u 277 11047 1394 >21.1 w1 656 6881 452 >20.4 m2 631 6676 452 >20.5 w2 582 6267 452 >20.9 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.20 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17297 SUBJECT: GRB 150110B: Swift-XRT refined Analysis DATE: 15/01/11 10:32:05 GMT FROM: Phil Evans at U of Leicester D.N. Burrows (PSU), J.A. Kennea (PSU), B.P. Gompertz (U. Leicester), J.P. Osborne (U. Leicester), V. D'Elia (ASDC), M. de Pasquale (INAF-IASFPA), A. Maselli (INAF-IASFPA), V. Mangano (PSU) and P.A. Evans report on behalf of the Swift-XRT team: We have analysed 8.9 ks of XRT data for GRB 150110B (Evans et al. GCN Circ. 17291), from 73 s to 29.9 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Beardmore et al. (GCN Circ. 17294). The light curve can be modelled with a power-law decay with a decay index of alpha=1.01 (+/-0.07). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.06 (+0.28, -0.26). The best-fitting absorption column is 6.0 (+1.9, -1.7) x 10^21 cm^-2, in excess of the Galactic value of 2.4 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.1 x 10^-11 (7.1 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 6.0 (+1.9, -1.7) x 10^21 cm^-2 Galactic foreground: 2.4 x 10^21 cm^-2 Excess significance: 3.6 sigma Photon index: 2.06 (+0.28, -0.26) If the light curve continues to decay with a power-law decay index of 1.01, 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 7.8 x 10^-14 (1.4 x 10^-13) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00624606. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17300 SUBJECT: GRB 150110B: Swift-BAT refined analysis DATE: 15/01/11 16:16:12 GMT FROM: Scott Barthelmy at NASA/GSFC H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), P. A. Evans (U Leicester), N. Gehrels (GSFC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-239 to T+963 sec from recent telemetry downlinks, we report further analysis of BAT GRB 150110B (trigger #624606) (Evans, et al., GCN Circ. 17291). The BAT ground-calculated position is RA, Dec = 289.374, 32.529 deg, which is RA(J2000) = 19h 17m 29.7s Dec(J2000) = +32d 31' 43.2" with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 96%. The mask-weighted light curve shows two peaks starting at ~T-8 sec, peaking at ~T-5 and ~T+2 sec, and ending at ~T+10 sec. T90 (15-350 keV) is 10.6 +- 0.95 sec (estimated error including systematics). The time-averaged spectrum from T-7.94 to T+3.77 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.89 +- 0.13. The fluence in the 15-150 keV band is 4.9 +- 0.4 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+2.00 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. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/624606/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17305 SUBJECT: GRB 150110B: Khureltogot optical upper limit DATE: 15/01/17 19:51:52 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), S. Schmalz (AIP), N. Tungalag (Research Center of Astronomy and Geophysics MAS), A. Volnova (IKI), I.Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB GRB 150110B (Evans et al., GCN 17291) with ORI-40 telescope of Khureltogot observatory. We obtained several unfiltered images on Jan. 10 starting on (UT) 22:31:36. In a combined image of the first 40 frames we do not detect any optical source within enhanced Swift-XRT position (Beardmore et al., GCN 17294). A photometry of the combined image is following Date UT start t-T0 Filter Exp. ULimit (3sigma) (mid, days) (s) 2015-01-10 22:31:36 0.03113 none 40*60 19.3 The photometry is based on USNO-B1.0 stars USNO-B1_id RA DEC R2 1224-0426323 289.294781 +32.470745 13.52 1225-0423392 289.295778 +32.569009 13.80 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17322 SUBJECT: GRB 150110B: AMI 15 GHz detection of possible radio counterpart DATE: 15/01/20 17:33:34 GMT FROM: Gemma Anderson at U of Oxford G. E. Anderson, R. P. Fender, T. D. Staley (University of Oxford), A. J. van der Horst (George Washington University), A. Rowlinson (CASS) We observed the position of GRB 150110B (Evans et al., GCN 17291) at 15 GHz with the Arcminute Microkelvin Imager (AMI-LA) starting on 2015 Jan 14.466 to 14.632 UT and 2015 Jan 16.415 to Jan 16.581, corresponding to 3.5 and 5.5 days post-burst. On these two dates we have detected a radio source coincident with the Swift-XRT position (Beardmore et al., GCN 17294) with a preliminary flux of 0.25 +/- 0.05 mJy and 0.47 +/- 0.05 mJy, respectively. There are no catalogued radio sources at this position. An earlier observation was conducted on 2015 Jan 11.434 to 11.580 UT, corresponding to 0.5 days post-burst, yielding a 3 sigma flux upper limit of 0.13 mJy. Further AMI monitoring is planned. We thank the AMI staff for scheduling these observations.