//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18657 SUBJECT: GRB 151205A: Swift detection of a burst DATE: 15/12/05 16:01:30 GMT FROM: Scott Barthelmy at NASA/GSFC J. R. Cummings (NASA/UMBC), S. D. Barthelmy (GSFC), D. N. Burrows (PSU), P. D'Avanzo (INAF-OAB), C. Gronwall (PSU), J. A. Kennea (PSU), F. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB), D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the Swift Team: At 15:46:00 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 151205A (trigger=666352). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 229.282, +35.769, which is RA(J2000) = 15h 17m 08s Dec(J2000) = +35d 46' 09" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a couple overlapping peaks with a total duration of about 25 sec. The peak count rate was ~2000 counts/sec (15-350 keV), at ~1 sec after the trigger. The XRT began observing the field at 15:47:32.7 UT, 91.8 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source with an enhanced position: RA, Dec 229.2892, 35.7439 which is equivalent to: RA(J2000) = 15h 17m 09.41s Dec(J2000) = +35d 44' 38.0" with an uncertainty of 2.3 arcseconds (radius, 90% containment). This location is 92 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 (1.58 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 4.7 (+3.55/-2.93) x 10^21 cm^-2 (90% confidence). The initial flux in the 2.5 s image was 1.31e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 100 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 0.02. Burst Advocate for this burst is J. R. Cummings (jayc AT milkyway.gsfc.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: 18658 SUBJECT: GRB 151205A: Enhanced Swift-XRT position DATE: 15/12/05 20:26:56 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 2174 s of XRT Photon Counting mode data and 3 UVOT images for GRB 151205A, 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 = 229.28861, +35.74392 which is equivalent to: RA (J2000): 15h 17m 9.27s Dec (J2000): +35d 44' 38.1" with an uncertainty of 1.8 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: 18660 SUBJECT: GRB 151205A: Swift/UVOT Upper Limits DATE: 15/12/05 23:00:57 GMT FROM: Lea Hagen at PSU L. M. Z. Hagen (PSU) and J. R. Cummings (NASA/UMBC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 151205A 101 s after the BAT trigger (Cummings et al., GCN Circ. 18657). No optical afterglow consistent with the XRT position (Osborne et al. GCN Circ. 18658) 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 101 5796 383 >21.15 v 590 6207 236 >19.25 b 514 5591 236 >20.14 u 259 6713 552 >20.21 w1 639 6617 413 >20.10 m2 4776 6412 393 >20.07 w2 565 6002 236 >19.95 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.02 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18663 SUBJECT: GRB 151205A: Garching Telescope Upper Limit DATE: 15/12/05 23:49:31 GMT FROM: Alexander Kann at TLS Tautenburg T. Schweyer (MPE Garching) and D. A. Kann (TLS Tautenburg) report on behalf of the GROND team: We observed the field of GRB 151205A (Swift trigger 666352; J. R. Cummings et al., GCN #18657) with the Garching 0.6m telescope. Observations started at 16:24:57 UT on 2015-12-05, about 39 min after the GRB trigger. They were performed at an average airmass of 3.4 during evening twilight. We obtained 6 images of 180s exposure time in R (for a total exposure time of 18 min) with the midtime at 16:35:18 UT (MJD=57361.691180). We do not detect a source within the 1".8 enhanced XRT error circle (J. P. Osborne et al., GCN #18658), down to a limiting magnitude of R(AB) > 19.4 mag. The R band is calibrated against SDSS DR8. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18664 SUBJECT: GRB 151205A: Fermi GBM detection DATE: 15/12/06 00:08:29 GMT FROM: Matthew Stanbro at UAH/Fermi Matthew Stanbro (UAH) reports on behalf of the Fermi GBM Team: "At 15:46:01.90 UT on 05 December 2015, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 151205A (trigger 471023165 / 151205657) which was also detected by the Swift/BAT (Cummings et al. 2015, GCN 18657). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight at the GBM trigger time is 76 degrees. The GBM light curve consists of several episodes with a duration (T90) of about 56 s (50-300 keV). The time-averaged spectrum from T0-2.05 s to T0+55.30 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is 1.06 +/- 0.48 and the cutoff energy, parameterized as Epeak, is 153 +/- 12 keV The event fluence (10-1000 keV) in this time interval is (2.56 +/- 0.21)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0-1.34 s in the 10-1000 keV band is 1.36 +/- 0.15 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog." -- Matthew C. Stanbro Fermi GBM Graduate Research Assistant University of Alabama in Huntsville //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18668 SUBJECT: GRB 151205A, Swift-BAT refined analysis DATE: 15/12/06 05:09:17 GMT FROM: Scott Barthelmy at NASA/GSFC M. Stamatikos (OSU), 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), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-315 to T+934 sec from the recent telemetry downlinks, we report further analysis of BAT GRB 151205A (trigger #666352) (Cummings, et al., GCN Circ. 18657). The BAT ground-calculated position is RA, Dec = 229.291, 35.767 deg, which is RA(J2000) = 15h 17m 09.7s Dec(J2000) = +35d 46' 01.7" with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 93%. The mask-weighted light curve shows several overlapping peaks starting at ~T-10 sec, peaking at ~T+3 sec, with a long tail out to T+170 sec. T90 (15-350 keV) is 62.8 +- 12.3 sec (estimated error including systematics). The time-averaged spectrum from T-4.0 to T+69.5 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.17 +- 0.13. The fluence in the 15-150 keV band is 1.4 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+1.98 sec in the 15-150 keV band is 0.6 +- 0.1 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/666352/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18669 SUBJECT: GRB 151205A: Swift-XRT refined Analysis DATE: 15/12/06 16:01:04 GMT FROM: Phil Evans at U of Leicester B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), T.G.R. Roegiers (PSU), C. Pagani (U. Leicester), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), A. Maselli (INAF-IASFPA), A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB) and J.R. Cummings report on behalf of the Swift-XRT team: We have analysed 7.1 ks of XRT data for GRB 151205A (Cummings et al. GCN Circ. 18657), from 81 s to 18.6 ks after the BAT trigger. The data comprise 133 s in Windowed Timing (WT) mode (the first 9 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN Circ. 18658). The light curve can be modelled with an initial power-law decay with an index of alpha=0.3 (+/-0.4), followed by a break at T+131 s to an alpha of 1.73 (+0.07, -0.06). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.23 (+0.14, -0.13). The best-fitting absorption column is 5.6 (+1.5, -1.3) x 10^21 cm^-2, in excess of the Galactic value of 1.6 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.90 (+0.31, -0.29) and a best-fitting absorption column of 7.4 (+2.5, -2.1) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.7 x 10^-11 (7.8 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 7.4 (+2.5, -2.1) x 10^21 cm^-2 Galactic foreground: 1.6 x 10^20 cm^-2 Excess significance: 5.6 sigma Photon index: 1.90 (+0.31, -0.29) If the light curve continues to decay with a power-law decay index of 1.73, the count rate at T+24 hours will be 2.1 x 10^-4 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 9.9 x 10^-15 (1.6 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/00666352. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18676 SUBJECT: GRB 151205A: Khureltogot upper limit DATE: 15/12/09 10:19:21 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Volnova (IKI), S. Schmalz (AIP), E. Mazaeva (IKI), N. Tungalag (Research Center of Astronomy and Geophysics MAS), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of Swift GRB 151205A (Cummings et al., GCN 18657) with ORI-40 telescope of Khureltogot observatory starting on Dec., 5 (UT) 20:49:25, i.e. ~6 hours after the burst trigger. We do not detect any object within enhanced XRT error circle (Osborne et al., GCN 18658). Photometry of the field is following Date UT start t-T0 Filter Exp. Upper_Limit (3sigma) (mid, days) (s) 2015-12-05 20:49:25 0.24451 none 90*60 21.3 Photometry is based on nearby SDSS stars, R magnitude deduced from Lupton's transformations. SDSS id R(Lupton) J151723.45+354524.6 13.849 0.011 J151723.30+354351.0 14.562 0.012 J151718.79+354350.3 15.801 0.013