//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16467 SUBJECT: GRB 140628A: Swift detection of a burst DATE: 14/06/28 14:01:58 GMT FROM: David Palmer at LANL E. Sonbas (NASA/GSFC/Adiyaman Univ.), M. G. Bernardini (INAF-OAB), P. D'Avanzo (INAF-OAB), H. A. Krimm (CRESST/GSFC/USRA), N. P. M. Kuin (UCL-MSSL), A. Y. Lien (NASA/GSFC/ORAU), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the Swift Team: At 13:35:37 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 140628A (trigger=602803). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 40.661, -0.366 which is RA(J2000) = 02h 42m 39s Dec(J2000) = -00d 21' 58" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single-peaked structure with a duration of about 10 sec. The peak count rate was ~2500 counts/sec (15-350 keV), at ~1 sec after the trigger. The XRT began observing the field after coming out of SAA mode at 13:39:40.3 UT, 243 seconds after the BAT trigger. No source was detected in 20 s of promptly downlinked data. We are waiting for the full dataset to detect and localize the XRT counterpart. UVOT took a finding chart exposure of 48 seconds with the White filter starting 278 seconds after the BAT trigger. No credible afterglow candidate has been found in a partial 2.7'x2.7' sub-image. Results from the list of sources generated on-board are not available at this time. Burst Advocate for this burst is E. Sonbas (edasonbas AT yahoo.com). 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: 16470 SUBJECT: GRB 140628A: Swift-XRT afterglow detection and enhanced position DATE: 14/06/28 18:52:42 GMT FROM: Maria Grazia Bernardini at INAF/Brera P. D'Avanzo, M.G. Bernardini, A. Melandri (INAF/OAB), P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team: Using promptly downlinked data we find an uncatalogued and fading X-ray source. Using 40 s of XRT Photon Counting mode data and 1 UVOT image, 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 =40.66674, -0.38488 which is equivalent to: RA (J2000): 02 42 40.02 Dec (J2000): -00 23 05.6 with an uncertainty of 2.5 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 is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16471 SUBJECT: GRB 140628A: Swift/UVOT Detection DATE: 14/06/28 21:31:59 GMT FROM: Mike Siegel at PSU/Swift MOC M. H. Siegel (PSU), N. P. M. Kuin (UCL-MSSL) and E. Sonbas (NASA/GSFC/Adiyaman Univ.) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 140628A 278 s after the BAT trigger (Sonbas et al., GCN Circ. 16467). A source consistent with the XRT position (D'Avanzo et al. GCN Circ. 16470) is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 02:42:39.88 = 40.66617 (deg.) Dec (J2000) = -00:23:05.7 = -0.38491 (deg.) with an estimated uncertainty of 0.46 arc sec. (radius, 90% confidence). Preliminary detections and 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 278 327 48 17.70 +/- 0.08 v 3749 3949 197 19.08 +/- 0.28 b 4569 4769 197 >20.2 u 4364 4564 197 >19.5 w1 4159 4359 197 >19.8 m2 3954 4154 197 >21.2 w2 9366 10266 886 >21.1 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.03 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16472 SUBJECT: GRB 140628A: Swift/UVOT Detection DATE: 14/06/28 21:52:10 GMT FROM: Paul Kuin at MSSL N. P. M. Kuin (UCL-MSSL) and E. Sonbas (NASA/GSFC/Adiyaman Univ.) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 140628A 278 s after the BAT trigger (Sonbas et al., GCN Circ. 16467). A source consistent with the XRT position (D'Avanzo et al. GCN Circ. 16470) is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 02:42:39.88 = 40.66617 (deg.) Dec (J2000) = -00:23:05.7 = -0.38491 (deg.) with an estimated uncertainty of 0.46 arc sec. (radius, 90% confidence). Preliminary detections and 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 278 327 48 17.43 +/- 0.08 white 3593 4974 300 >21.0 v 3749 3949 197 19.08 +/- 0.28 b 4569 4769 197 >20.2 u 4364 4564 197 >19.5 w1 4159 4359 197 >19.8 m2 3954 4154 197 >21.2 w2 9366 10266 886 >21.1 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.03 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16473 SUBJECT: GRB 140628A: Swift-BAT refined analysis DATE: 14/06/28 23:53:48 GMT FROM: Scott Barthelmy at NASA/GSFC W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), E. Sonbas (NASA/GSFC/Adiyaman Univ.), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team): Using the data set from T-60 to T+243 sec from recent telemetry downlinks, we report further analysis of BAT GRB 140628A (trigger #602803) (Sonbas, et al., GCN Circ. 16467). The BAT ground-calculated position is RA, Dec = 40.672, -0.378 deg which is RA(J2000) = 02h 42m 41.2s Dec(J2000) = -00d 22' 39.8" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 73%. The mask-weighted light curve ~3 overlapping peaks starting at ~T-15 sec, peaking at ~T+2 sec, and ending at ~T+30 sec. T90 (15-350 keV) is 10.5 +- 0.9 sec (estimated error including systematics). The time-averaged spectrum from T-1.24 to T+11.12 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.56 +- 0.09. The fluence in the 15-150 keV band is 1.3 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+0.94 sec in the 15-150 keV band is 2.8 +- 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/602803/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16474 SUBJECT: GRB 140628A: Zadko observatory - Gingin optical observations DATE: 14/06/29 01:25:11 GMT FROM: Alain Klotz at IRAP-CNRS-OMP A. Klotz, D. Turpin (IRAP-CNRS-OMP), D. Macpherson (UWA/ICRAR), D. Coward (UWA), M. Boer, B. Gendre, K. Siellez, H. Dereli, O. Bardho (UNS-CNRS-OCA), A. Williams (PO-UWA), R. Martin (PO-UWA) report: We imaged the field of GRB 140628A detected by SWIFT (trigger 602803) with the Zadko robotic telescope (D=100cm) located at the observatory - Gingin, Australia. The observations started 6.72h after the GRB trigger. The elevation of the field increased from 22 degrees above horizon and weather conditions were poor. We co-added a series of exposures. We do not see any optical counterpart at the UVOT position mentioned by Kuin et al. (GCNC 16472): t0+6.72h to t0+7.27h : Rlim = 19.9 Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16475 SUBJECT: GRB 140628A: Swift-XRT refined Analysis DATE: 14/06/29 06:59:22 GMT FROM: Paolo D'Avanzo at INAF-OAB P. D'Avanzo, M.G. Bernardini, A. Melandri (INAF/OAB), P.A. Evans (U. Leicester) and E. Sonbas (NASA/GSFC/Adiyaman Univ.) report on behalf of the Swift-XRT team: We have analysed 8.2 ks of XRT data for GRB 140628A (Sonbas et al. GCN Circ. 16467), from 231 s to 23.2 ks after the BAT trigger. The data comprise 47 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. Using 5310 s of PC mode data and 10 UVOT images, we find an enhanced XRT position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 40.66617, -0.38489 which is equivalent to: RA (J2000): 02h 42m 39.88s Dec(J2000): -00d 23' 05.6" with an uncertainty of 1.5 arcsec (radius, 90% confidence). The light curve can be modelled with a power-law decay with a decay index of alpha=1.21 (+0.03, -0.04). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.88 (+0.19, -0.18). The best-fitting absorption column is 8.9 (+5.3, -4.7) x 10^20 cm^-2, in excess of the Galactic value of 3.2 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 3.5 x 10^-11 (4.2 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 8.9 (+5.3, -4.7) x 10^20 cm^-2 Galactic foreground: 3.2 x 10^20 cm^-2 Excess significance: 2.0 sigma Photon index: 1.88 (+0.19, -0.18) If the light curve continues to decay with a power-law decay index of 1.21, the count rate at T+24 hours will be 4.5 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.6 x 10^-13 (1.9 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/00602803. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16476 SUBJECT: GRB 140628A: GROND observation of the afterglow DATE: 14/06/29 13:39:38 GMT FROM: Sebastian Schmidl at TLS Tautenburg C. Delvaux (MPE Garching), S. Schmidl (TLS Tautenburg), and J. Greiner (MPE Garching) report on behalf of the GROND team: We observed the field of GRB 140628A (Swift trigger 602803; Sonbas et al., GCN 16467) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2m MPG telescope at ESO La Silla Observatory (Chile). Observations started at 08:39 UT on June 29, 2014, 19.1 hrs after the GRB trigger. They were performed at an average seeing of 1.6" and at an average airmass of 1.6. We detect a source consistent with the Swift/UVOT position, reported by Siegel et al. (GCN 16471). Based on a total exposure of 50 min in g'r'i' and 40 min in JHK, at a mid-time of 20.2 hrs after the burst, we measure the following preliminary magnitudes (in AB): g' = 23.6 +/- 0.2 mag r' = 23.1 +/- 0.1 mag i' = 22.9 +/- 0.2 mag J > 21.2 mag, H > 20.1 mag, and K > 19.1 mag. In addition we measure z' = 22.1 +/- 0.2 (in AB magnitude system), based on a total exposure of 25 min, at a midtime of 20.5 hrs after burst. Given magnitudes are calibrated against SDSS (g'r'i'z') as well as 2MASS (JHK) field stars and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V) = 0.03 mag in the direction of the burst (Schlegel et al. 1998).