//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19560 SUBJECT: GRB 160624A: Swift detection of a short burst DATE: 16/06/24 11:41:14 GMT FROM: Scott Barthelmy at NASA/GSFC A. D'Ai (INAF-IASFPA), S. D. Barthelmy (GSFC), N. Gehrels (NASA/GSFC), C. Gronwall (PSU), H. A. Krimm (CRESST/GSFC/USRA), A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC), A. Maselli (INAF-IASFPA) and E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift Team: At 11:27:01 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 160624A (trigger=701288). Swift slewed immediately to the short burst. The BAT on-board calculated location is RA, Dec 330.203, +29.634 which is RA(J2000) = 22h 00m 49s Dec(J2000) = +29d 38' 02" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a single spike structure with a duration of about 0.25 sec. The peak count rate was ~7000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 11:28:15.0 UT, 73.7 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 330.19123, 29.64388 which is equivalent to: RA(J2000) = 22h 00m 45.90s Dec(J2000) = +29d 38' 38.0" with an uncertainty of 3.9 arcseconds (radius, 90% containment). This location is 51 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. We cannot determine whether the source is fading at the present time. No spectrum from the promptly downlinked event data is yet available to determine the column density. UVOT took a finding chart exposure of 150 seconds with the White filter starting 76 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 0.07. Burst Advocate for this burst is A. D'Ai (antonino.dai AT ifc.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/too.html.) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19562 SUBJECT: GRB 160624A: Prompt enhanced Swift-XRT position DATE: 16/06/24 12:05:29 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 160624A, we find an enhanced XRT position of the afterglow: RA, Dec: 330.1928, 29.6443 which is equivalent to: RA (J2000) = 22 00 46.27 Dec (J2000) = +29 38 39.4 with an uncertainty of 2.3 arcseconds (radius, 90% confidence). Analysis of the promptly available data is online at http://www.swift.ac.uk/sper/701288. 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: 19565 SUBJECT: GRB160624A:possible GRB host redshift DATE: 16/06/24 13:38:07 GMT FROM: Antonino Cucchiara at NASA/GSFC A. Cucchiara (STScI/GSFC) and A. J. Levan (U. Warwick) report on behalf of a larger collaboration: On June 24, 12:12:58 UT (~T+46min after the burst) we observed the field of the Swift short GRB160624A (D’Ai et al. GCN 19560, Evans et al. GCN 19562) with the GMOS-N camera mounted on the Gemini North telescope. In a 180s r’-band acquisition image a galaxy is identified within the enhanced XRT error circle. The galaxy is also visible in SDSS. We performed a 900s spectroscopic observation with the R400 grating covering the 3800-8100 Angstrom wavelength range. The galaxy spectrum reveals emission features of [OIII]5007, H-beta and [OII]3727 at the common redshift of z=0.483. We also obtained deeper r’ band imaging with the GMOS camera: no other source is detected in the enhanced error circle down to a limiting magnitude of r’~25.5, although we are not sensitive to possible faint point source superposed on the galaxy light. We thank the Gemini staff for their extremely rapid response, in particular Andrew Stephens. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19566 SUBJECT: GRB 160624A: Enhanced Swift-XRT position DATE: 16/06/24 15:42:50 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 371 s of XRT Photon Counting mode data and 1 UVOT images for GRB 160624A, 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 = 330.19271, +29.64373 which is equivalent to: RA (J2000): 22h 00m 46.25s Dec (J2000): +29d 38' 37.4" with an uncertainty of 1.9 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: 19569 SUBJECT: GRB 160624A, Swift-BAT refined analysis DATE: 16/06/24 19:38:17 GMT FROM: Amy Lien at GSFC T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), A. D'Ai (INAF-IASFPA), 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) (i.e. the Swift-BAT team): Using the data set from T-240 to T+581 sec from the recent telemetry downlink, we report further analysis of BAT GRB 160624A (trigger #701288) (D'Ai et al., GCN Circ. 19560). The BAT ground-calculated position is RA, Dec = 330.210, 29.667 deg which is RA(J2000) = 22h 00m 50.5s Dec(J2000) = +29d 40' 02.4" with an uncertainty of 2.6 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%. The mask-weighted light curve shows a single pulse that starts at ~T0, peaks at ~T+0.1 s, and ends at ~T+0.3. T90 (15-350 keV) is 0.2 +- 0.1 sec (estimated error including systematics). The time-averaged spectrum from T+0.0 to T+0.3 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 0.57 +- 0.45. The fluence in the 15-150 keV band is 4.0 +- 0.9 x 10^-8 erg/cm2. The 1-sec peak photon flux measured from T-0.29 sec in the 15-150 keV band is 0.5 +- 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/701288/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19570 SUBJECT: GRB 160624A: Fermi GBM observation DATE: 16/06/24 20:19:03 GMT FROM: Eric Burns at U of Alabama R. Hamburg (UAH) and A. von Kienlin (MPE) report on behalf of the Fermi GBM Team: "At 11:27:01.35 UT on 24 June 2016, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 160624A (trigger 488460425 / 160624477), which was also detected by the Swift (D'Ai et al. 2016, GCN 19560) 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 a single peak with a duration (T90) of about 0.4 s (50-300 keV). The time-averaged spectrum from T0-0.064 s to T0+0.192 s is well fit by a power law function with an exponential high-energy cutoff. The power law index is -0.40 +/- 0.28 and the cutoff energy, parameterized as Epeak, is 841 +/- 358 keV. The event fluence (10-1000 keV) in this time interval is (5.2 +/- 0.5)E-07 erg/cm^2. The 0.064-sec peak photon flux measured starting from T0+0.00 s in the 10-1000 keV band is 6.4 +/- 1.3 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: 19571 SUBJECT: GRB 160624A: MITSuME Ishigakijima upper limits DATE: 16/06/25 01:40:48 GMT FROM: Daisuke Kuroda at OAO/NAOJ D. Kuroda (OAO, NAOJ), H. Hanayama, T. Miyaji, J. Watanabe (IAO, NAOJ), K. Yanagisawa (OAO, NAOJ), S.Nagayama (NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto) and N. Kawai(Tokyo Tech) report on behalf of the MITSuME and OISTER collaboration: We observed the field of GRB 151029A (D'Ai et al., GCNC 19560) with the optical three color (g', Rc and Ic) CCD camera attached to the Murikabushi 1m telescope of Ishigakijima Astronomical Observatory. The observation started on 2016-06-24 15:22:38 UT (~3.9h after the burst). We did not find any new point source within the enhanced XRT circle (Beardmore et al., GCNC 19566) in all the three bands. Three sigma upper limits of the OT are listed below. We used GSC2.3 catalog for flux calibration. #T0+[day] MID-UT T-EXP[sec] g' Rc Ic ----------------------------------------------------- 0.17131 15:33:41 1740.0 >20.5 >20.1 >19.3 ----------------------------------------------------- T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19573 SUBJECT: GRB 160624A: Swift-XRT refined Analysis DATE: 16/06/25 03:45:51 GMT FROM: Phil Evans at U of Leicester A.P. Beardmore (U. Leicester), P.A. Evans (U. 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) and A. D'Ai report on behalf of the Swift-XRT team: We have analysed 6.2 ks of XRT data for GRB 160624A (D'Ai et al. GCN Circ. 19560), from 58 s to 45.7 ks after the BAT trigger. The data comprise 72 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 Beardmore et al. (GCN Circ. 19562). The light curve can be modelled with a series of power-law decays. The initial decay index is alpha=0.8 (+0.4, -0.5). At T+126 s the decay steepens to an alpha of 3.0 (+1.1, -0.8) before breaking again at T+217 s to a final decay with index alpha=6.7 (+1.3, -0.7). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.73 (+0.31, -0.29). The best-fitting absorption column is 5.5 (+2.6, -2.2) x 10^21 cm^-2, in excess of the Galactic value of 9.1 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 4.6 x 10^-11 (6.5 x 10^-11) erg cm^-2 count^-1. A summary of the WT-mode spectrum is thus: Total column: 5.5 (+2.6, -2.2) x 10^21 cm^-2 Galactic foreground: 9.1 x 10^20 cm^-2 Excess significance: 3.4 sigma Photon index: 1.73 (+0.31, -0.29) If the light curve continues to decay with a power-law decay index of 6.7, the count rate at T+24 hours will be 3.8 x 10^-18 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.7 x 10^-28 (2.4 x 10^-28) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00701288. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19575 SUBJECT: GRB 160624A: Lulin observation DATE: 16/06/25 15:01:46 GMT FROM: Albert Kong at NTHU A.K.H. Kong (NTHU), M.Y. Lee, Y.-M. Lin (TFGHS), X. Hou (NTHU/YAO), C.Y. Liu (NTHU) We observed the field of GRB 160624A (D'Ai et al. GCN #19560) with the 1m telescope at the Lulin Observatory in Taiwan. We obtained a 600-s image with the SDSS r-band filter on 2016 June 24, 17:32 UT (~ 6 hours after the burst). Apart from the possible host galaxy that is also seen in SDSS (Cucchiara et al. GCN #19565), no new point source was detected at the enhanced XRT position (Beardmore et al. GCN #19566) with r > 22.2 mag. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19576 SUBJECT: GRB 160624A: Swift/UVOT Upper Limits DATE: 16/06/25 16:26:56 GMT FROM: Massimiliano de Pasquale at IASF-Palermo M. De Pasquale (UCL-MSSL) and A. D'Ai (INAF-IASFPA) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 160624A 77 s after the BAT trigger (D'Ai et al., GCN Circ. 19560). No optical afterglow consistent with the XRT position (Beardmore et al. GCN Circ. 19566) is detected in the initial and summed UVOT exposures, nor at the position of the SDSS galaxy mentioned by Cucchiara et al. (GCN Circ. 19565). 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 77 227 147 >20.8 u_FC 289 527 234 >20.0 white 77 6288 541 >21.5 v 5060 6657 352 >19.5 b 4445 6082 393 >20.7 u 289 12622 1073 >20.7 w1 5471 11954 1082 >20.8 m2 5266 11048 1082 >20.7 w2 4855 6494 393 >20.3 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.07 in the direction of the burst (Schlegel et al. 1998). -- Dr. Massimiliano De Pasquale Research associate - Swift UVOT scientist Mullard Space Science Laboratory, University College London //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19688 SUBJECT: GRB 160624A: 15 GHz upper limits from AMI DATE: 16/07/12 22:21:47 GMT FROM: Kunal Mooley at Oxford U K. P. Mooley, T. D. Staley, R. P. Fender (Oxford), G. E. Anderson (Curtin), T. Cantwell (Manchester), C. Rumsey, D. Titterington, S. 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 160624A (D'Ai et al., GCN 19560) 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 Jun 24.97, Jun 29.18, and Jul 02.05 (UT) do not reveal any radio source at the XRT location (Beardmore et al., GCN 19566), with 3sigma upper limits of 268 uJy, 93 uJy, and 114 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/.