//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14923 SUBJECT: GRB 130625A: Swift detection of a burst DATE: 13/06/25 07:15:01 GMT FROM: Dirk Grupe at PSU/Swift-XRT D. Grupe (PSU), V. D'Elia (ASDC), P. A. Evans (U Leicester), A. Y. Lien (NASA/GSFC/ORAU) and K. L. Page (U Leicester) report on behalf of the Swift Team: At 07:00:39 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 130625A (trigger=558982). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 343.268, +82.178 which is RA(J2000) = 22h 53m 04s Dec(J2000) = +82d 10' 42" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a multi-peak structure with a duration of about 30 sec. The peak count rate was ~1648 counts/sec (15-350 keV), at ~1 sec after the trigger. The XRT began observing the field at 07:02:16.7 UT, 97.2 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source with an enhanced position: RA, Dec 343.2798, 82.1734 which is equivalent to: RA(J2000) = 22h 53m 07.15s Dec(J2000) = +82d 10' 24.1" with an uncertainty of 2.6 arcseconds (radius, 90% containment). This location is 17 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 (1.06 x 10^21 cm^-2, Kalberla et al. 2005), with an excess column of 2.8 (+2.84/-2.37) x 10^21 cm^-2 (90% confidence). UVOT took a finding chart exposure of 150 seconds with the White filter starting 102 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 0.22. Burst Advocate for this burst is D. Grupe (dxg35 AT psu.edu). 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: 14924 SUBJECT: GRB 130625A: Enhanced Swift-XRT position DATE: 13/06/25 11:44:13 GMT FROM: Phil Evans at U of Leicester M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team. Using 1226 s of XRT Photon Counting mode data and 1 UVOT images for GRB 130625A, 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 = 343.27789, +82.17438 which is equivalent to: RA (J2000): 22h 53m 6.69s Dec (J2000): +82d 10' 27.8" with an uncertainty of 2.2 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: 14925 SUBJECT: GRB 130625A: Swift-BAT refined analysis DATE: 13/06/25 12:03:54 GMT FROM: Scott Barthelmy at NASA/GSFC D. M. Palmer (LANL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), D. Grupe (PSU), H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (GSFC), T. Sakamoto (AGU), 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 the recent telemetry downlink, we report further analysis of BAT GRB 130625A (trigger #558982) (Grupe, et al., GCN Circ. 14923). The BAT ground-calculated position is RA, Dec = 343.336, 82.171 deg, which is RA(J2000) = 22h 53m 20.6s Dec(J2000) = +82d 10' 17.1" with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 75%. The mask-weighted light curve shows two overlapping peaks starting at ~T-25sec, peaking at ~T+3 sec, and ending at ~T+60 sec. T90 (15-350 keV) is 38.1 +- 4.9 sec (estimated error including systematics). The time-averaged spectrum from T-28.17 to T+18.50 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.37 +- 0.09. The fluence in the 15-150 keV band is 1.8 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+2.54 sec in the 15-150 keV band is 1.2 +- 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/558982/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14927 SUBJECT: GRB 130625A: Nanshan optical upper limit DATE: 13/06/25 18:36:32 GMT FROM: Dong Xu at DARK/NBI D. Xu (DARK/NBI), A. Esamdin, L. Ma, C.-H. Bai, G.-J. Feng (XAO) report: We observed the field of GRB 130625A (Grupe et al., GCN 14923) using the 1m telescope located at Mt. Nanshan, Xinjiang Astronomical Observatory, China. We obtained 6x300s R-band frames with a mean time of 15:40:08 UT on 2013-06-25, (i.e., 8.658 hr after the burst). No optical source is detected within the enhanced XRT error circle (Goad et al., GCN 14924) in the stacked image, down to a limit magnitude of R=21.0 mag, calibrated with the USNO B1 catalog. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14928 SUBJECT: GRB 130625A: Swift/UVOT Upper Limits DATE: 13/06/25 20:34:02 GMT FROM: Mike Siegel at PSU/Swift MOC J. S. Linevsky (PSU/CBHS), M. H. Siegel (PSU), and D. Grupe (PSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 130625A 102 s after the BAT trigger (Grupe et al., GCN Circ. 14923). No optical afterglow consistent with the enhanced XRT position (Grupe et al. GCN Circ. 14924) 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 102 252 147 >20.96 white 595 1890 283 >21.34 v 644 1940 155 >19.34 b 570 1866 136 >20.21 u_FC 315 565 245 >20.26 u 315 2003 617 >20.81 uvw1 694 1989 136 >19.60 uvm2 844 6816 332 >20.04 uvw2 620 1916 155 >19.79 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.22 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14929 SUBJECT: GRB 130625A: MASTER afterglow limit DATE: 13/06/26 06:31:35 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov, A.Gabovich Blagoveschensk Educational State University, Blagoveschensk E. Gorbovskoy, V. Lipunov, D.Denisenko, V.Kornilov, D.Kuvshinov, N.Tyurina, N.Shatskiy, P.Balanutsa, D.Zimnukhov, A.Kuznetsov, V.V.Chazov Sternberg Astronomical Institute, Lomonosov Moscow State University K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University, Irkutsk A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Senik Kislovodsk Solar Station of the Pulkovo Observatory V.Krushinski, I.Zalozhnih, A. Popov Ural Federal University, Kourovka Hugo Levato and Carlos Saffe Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) Claudio Mallamaci, Carlos Lopez and Federico Podest Observatorio Astronomico Felix Aguilar (OAFA) MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Blagoveschensk was pointed to the GRB130625A 23177 sec s after notice time and 23214 sec after GRB time at 2013-06-25 13:27:34.231 UT. On our first (180s exposure) set we haven`t found optical transient within Swift error-box (D. Grupe et al. GCN 14923). The 5-sigma upper limit has been about 17.5 mag On coadd images images we received the following limits T_start T_finish T_mid t_mid-t_grb Exptime Filter Limit Coadd --------------------------------------------------------------------------- 13:27:34 14:17:44 13:52:39 24719 s 2700 s R 19.0 15 13:31:38 14:17:44 13:54:41 24841 s 2520 s W 19.5 14 The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14930 SUBJECT: GRB 130625A: Swift-XRT refined Analysis DATE: 13/06/26 07:15:04 GMT FROM: Phil Evans at U of Leicester J.A. Kennea (PSU), M.C. Stroh (PSU), D.N. Burrows (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), C. Pagani (U. Leicester), V. D'Elia (ASDC), A. Maselli (INAF-IASFPA), V. Mangano (INAF-IASFPA) and D. Grupe report on behalf of the Swift-XRT team: We have analysed 2.8 ks of XRT data for GRB 130625A (Grupe et al. GCN Circ. 14923), from 100 s to 25.1 ks after the BAT trigger. The data comprise 34 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Goad et al. (GCN. Circ 14924). The light curve can be modelled with a power-law decay with a decay index of alpha=1.70 (+0.21, -0.23). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.2 (+0.7, -0.6). The best-fitting absorption column is 4.8 (+3.3, -2.3) x 10^21 cm^-2, in excess of the Galactic value of 1.1 x 10^21 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.1 x 10^-11 (8.3 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 4.8 (+3.3, -2.3) x 10^21 cm^-2 Galactic foreground: 1.1 x 10^21 cm^-2 Excess significance: 2.6 sigma Photon index: 2.2 (+0.7, -0.6) If the light curve continues to decay with a power-law decay index of 1.70, the count rate at T+24 hours will be 5.3 x 10^-5 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.2 x 10^-15 (4.4 x 10^-15) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00558982. This circular is an official product of the Swift-XRT team.