//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16642 SUBJECT: GRB 140730A: Swift detection of a burst DATE: 14/07/30 20:04:06 GMT FROM: David Palmer at LANL C. B. Markwardt (NASA/GSFC), M. G. Bernardini (INAF-OAB), P. D'Avanzo (INAF-OAB), N. Gehrels (NASA/GSFC), F. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB) and D. M. Palmer (LANL) report on behalf of the Swift Team: At 19:43:51 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 140730A (trigger=607742). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 56.431, -66.539 which is RA(J2000) = 03h 45m 43s Dec(J2000) = -66d 32' 19" 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 5 sec (FWHM ~2-3 sec) The peak count rate was ~1800 counts/sec (15-350 keV), at ~1 sec after the trigger. The XRT began observing the field at 19:44:55.1 UT, 63.8 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 56.39573, -66.54597 which is equivalent to: RA(J2000) = 03h 45m 34.98s Dec(J2000) = -66d 32' 45.5" with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 56 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. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 7.59 x 10^20 cm^-2 (Willingale et al. 2013). UVOT took a finding chart exposure of 150 seconds with the White filter starting 68 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 0.09. Burst Advocate for this burst is C. B. Markwardt (Craig.Markwardt AT 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: 16643 SUBJECT: GRB 140730A: Prompt enhanced Swift-XRT position DATE: 14/07/30 20:14:28 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 140730A, we find an enhanced XRT position of the afterglow: RA, Dec: 56.3982, -66.5456 which is equivalent to: RA (J2000) = 03 45 35.56 Dec (J2000) = -66 32 44.0 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/607742. 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: 16644 SUBJECT: GRB 140730A: Enhanced Swift-XRT position DATE: 14/07/31 01:30:27 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 2499 s of XRT Photon Counting mode data and 5 UVOT images for GRB 140730A, 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 = 56.39911, -66.54516 which is equivalent to: RA (J2000): 03h 45m 35.79s Dec (J2000): -66d 32' 42.6" 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: 16645 SUBJECT: GRB 140730A: Swift/UVOT Upper Limits DATE: 14/07/31 01:35:22 GMT FROM: Mike Siegel at PSU/Swift MOC M. H. Siegel (PSU) and C. B. Markwardt (NASA/GSFC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 140730A 68 s after the BAT trigger (Markwardt et al., GCN Circ. 16642). No optical afterglow consistent with the XRT position (Evans GCN Circ. 16643) 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 68 218 147 >21.2 u_FC 280 530 246 >19.6 white 68 6182 396 >21.3 v 784 6593 413 >19.5 b 709 5978 216 >20.3 u 280 5772 462 >20.0 w1 660 5568 236 >21.1 m2 5162 6798 393 >20.4 w2 4753 6388 393 >20.6 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.09 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16646 SUBJECT: GRB 140730A: Swift-XRT refined Analysis DATE: 14/07/31 10:04:03 GMT FROM: Phil Evans at U of Leicester A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), B.P. Gompertz (U. Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), M. de Pasquale (INAF-IASFPA), M.C. Stroh (PSU), D.N. Burrows (PSU), J.A. Kennea (PSU) and C.B. Markwardt report on behalf of the Swift-XRT team: We have analysed 6.1 ks of XRT data for GRB 140730A (Markwardt et al. GCN Circ. 16642), from 50 s to 39.5 ks after the BAT trigger. The data comprise 17 s in Windowed Timing (WT) mode (the first 7 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 Goad et al. (GCN Circ. 16643). The light curve can be modelled with an initial power-law decay with an index of alpha=2.4 (+0.4, -0.3), followed by a break at T+234 s to an alpha of 0.57 (+/-0.07). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.92 (+0.25, -0.23). The best-fitting absorption column is 3.0 (+1.1, -1.0) x 10^21 cm^-2, in excess of the Galactic value of 7.6 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 3.9 x 10^-11 (5.5 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 3.0 (+1.1, -1.0) x 10^21 cm^-2 Galactic foreground: 7.6 x 10^20 cm^-2 Excess significance: 3.8 sigma Photon index: 1.92 (+0.25, -0.23) If the light curve continues to decay with a power-law decay index of 0.57, the count rate at T+24 hours will be 10.0 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.9 x 10^-13 (5.5 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/00607742. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16647 SUBJECT: GRB 140730A: LCO-Sutherland observations DATE: 14/07/31 15:02:56 GMT FROM: Simone Dichiara at Ferrara U/Italy S. Dichiara, C. Guidorzi (U. Ferrara), C.G. Mundell (LJMU), A. Gomboc (U. Ljubljana) on behalf of a large collaboration report: One of the Las Cumbres Observatory 1-m telescopes in Sutherland (South Africa) began observing Swift GRB 140730A (Markwardt et al. GCN Circ 16642) on July 31 at 01:16:34 UT, i.e. ~5.5 hours after the BAT trigger, with the r' and i' filters. Within the enhanced XRT error circle (Goad et al. GCN Circ. 16644) we found nothing down to the following limit: Mid time from Total Exp Filter Magnitude trigger (hr) (s) ------------------------------------------------- 5.64 120x5 r' > 20.0 5.83 120x5 i' > 19.8 ------------------------------------------------- Magnitudes are calibrated against nearby USNO-B1 stars. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16652 SUBJECT: GRB 140730A, Swift-BAT refined analysis DATE: 14/08/01 19:12:39 GMT FROM: Amy Lien at 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), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+902 sec from the recent telemetry downlink, we report further analysis of BAT GRB 140730A (trigger #607742) (Markwardt, et al., GCN Circ. 16642). The BAT ground-calculated position is RA, Dec = 56.350, -66.580 deg which is RA(J2000) = 03h 45m 24.0s Dec(J2000) = -66d 34' 48.7" with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%. The mask-weighted light curve shows several overlapping pulses. The first major pulse starts at ~T-14s, peaks at ~T-13 s, and ends at ~T-4 s. The second major pulse starts at ~T+0 s, peaks at ~T+1s, and ends at ~T+5 s. The whole burst structure ends at ~T+41 s. T90 (15-350 keV) is 41.3 +- 3.7 sec (estimated error including systematics). The time-averaged spectrum from T-13.5 to T+29.6 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.50 +- 0.32. The fluence in the 15-150 keV band is 2.8 +- 0.5 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+1.17 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/607742/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16664 SUBJECT: GRB 140730A: GROND Upper limits DATE: 14/08/02 23:55:14 GMT FROM: Alexander Kann at TLS Tautenburg D. A. Kann (TLS Tautenburg), C. Delvaux and Jochen Greiner (both MPE Garching) report on behalf of the GROND team: We observed the field of GRB 140730A (Swift trigger 607742; Markwardt et al., GCN #16642) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla Observatory (Chile). Observations started at 08:36 UT on 2014-08-02, 2.52 days after the GRB trigger. They were performed at an average seeing of 1".2 and at an average airmass of 1.4. Based on images with exposure times of 2250 s in g'r'i'z' and 1200 s in JHK, we do not detect a source within the Swift-XRT error circle reported by Goad et al. (GCN #16644) down to to the following 3-sigma AB magnitudes: g' > 25.3 mag, r' > 25.4 mag, i' > 24.7 mag, z' > 24.4 mag, J > 21.0 mag, H > 20.3 mag, and K > 18.0 mag. The given limits are derived based on calibrating the images against the GROND zeropoints and 2MASS field stars and are not corrected for the Galactic foreground extinction corresponding to a reddening of E_(B-V)= 0.09 in the direction of the burst (Schlegel et al. 1998).