//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15013 SUBJECT: GRB 130722A: Swift detection of a burst DATE: 13/07/22 08:30:55 GMT FROM: David Palmer at LANL E. Troja (NASA/GSFC/UMCP), V. D'Elia (ASDC), C. J. Mountford (U Leicester), C. Pagani (U Leicester), K. L. Page (U Leicester) and D. M. Palmer (LANL) report on behalf of the Swift Team: At 08:19:19 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 130722A (trigger=563213). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 260.670, -2.979 which is RA(J2000) = 17h 22m 41s Dec(J2000) = -02d 58' 44" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a triple-peaked structure with a duration of about 120 sec. The peak count rate was ~8500 counts/sec (15-350 keV), at ~72 sec after the trigger. The XRT began observing the field at 08:21:10.4 UT, 111.2 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 260.6530, -2.9728 which is equivalent to: RA(J2000) = +17h 22m 36.72s Dec(J2000) = -02d 58' 22.1" with an uncertainty of 4.7 arcseconds (radius, 90% containment). This location is 65 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy. The initial flux in the 2.5 s image was 8.65e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 120 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 0.63. Burst Advocate for this burst is E. Troja (eleonora.troja 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: 15015 SUBJECT: GRB 130722A: Faulkes Telescope South optical candidate DATE: 13/07/22 10:07:51 GMT FROM: Andrea Melandri at Liverpool John Moores U A. Melandri (INAF/OAB), C. Guidorzi (U. Ferrara), J. Japelj (U. Ljubljana), D. Kopac (U. Ljubljana), C.G. Mundell (LJMU) and A. Gomboc (U. Ljubljana) report: The 2-m Faulkes Telescope South automatically began observing GRB 130722A (Troja et al. GCN Circ. 15013) on July 22 2013 at 08:21:29 UT (~130 s after the burst trigger). We find a fading object at coordinates RA(2000.0)= 17:22:36.47 Dec(2000.0)= -02:58:21.6 (error 1.3") with the following magnitudes Mid time from Total Exp Filter Magnitude trigger (min) (s) -------------------------------------------------------------- 12.37 1x30 R 18.0 +- 0.1 18.07 1x60 R 18.3 +- 0.1 -------------------------------------------------------------- Magnitudes are calibrated against nearby USNO-B1 stars, performing aperture photometry of the proposed optical counterpart above together with the nearby object located at RA(2000.0)=17:22:36.54, Dec(2000.0)=-02:58:22.1. The latter might be related to the OT, has a distance of 1.2" from the candidate and a catalogued magnitude of R2=19.7. It looks extended and might be the host galaxy of GRB 130722A. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15017 SUBJECT: GRB 130722A: Skynet/GORT observations DATE: 13/07/22 17:21:26 GMT FROM: Adam S. Trotter at UNC-Chapel Hill/PROMPT/Skynet A. Trotter, D. Reichart, K. McLin, L. Cominsky, T. Berger, M. Carroll, H. T. Cromartie, R. Egger, A. Foster, C. Foster, N. Frank, J. Haislip, K. Ivarsen, D. James, A. LaCluyze, M. Maples, J. Moore, M. Nysewander, E. Speckhard, P. Taylor, and J. A. Crain report: Skynet observed the Swift/BAT localization of GRB 130722A (Troja et al., GCN 15013, Swift trigger 563213) in the Rc and Ic bands with the 14" GLAST Optical Robotic Telescope (GORT) at the Hume observatory in California, beginning at t=100s post trigger and continuing until t~1hr. In stacked exposures, we marginally detect a source in both bands at the afterglow position reported by Melandri et al. (GCN 15015). Photometry is calibrated to 3 USNO-B1 stars in the field: band t[min] exp[min] mag Rc 38 31 18.6 (+0.4, -0.3) Ic 41 35 17.6 (+0.3, -0.2) No further Skynet observations are scheduled. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15018 SUBJECT: GRB 130722A: Swift-XRT refined Analysis DATE: 13/07/22 21:30:03 GMT FROM: Phil Evans at U of Leicester D.N. Burrows (PSU), C. Pagani (U. Leicester), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), P. D'Avanzo (INAF-OAB), J.A. Kennea (PSU), V. Mangano (PSU) and E. Troja report on behalf of the Swift-XRT team: We have analysed 7.3 ks of XRT data for GRB 130722A (Troja et al. GCN Circ. 15013), from 117 s to 17.7 ks after the BAT trigger. The data comprise 739 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The refined XRT position is RA, Dec = 260.65405, -2.97376 which is equivalent to: RA (J2000): 17 22 36.97 Dec(J2000): -02 58 25.5 with an uncertainty of 3.5 arcsec (radius, 90% confidence). The late-time light curve (from T0+3.6 ks) can be modelled with a power-law decay with a decay index of alpha=1.10 (+/-0.11). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.21 (+/-0.05). The best-fitting absorption column is 4.18 (+0.18, -0.17) x 10^21 cm^-2, in excess of the Galactic value of 1.2 x 10^21 cm^-2 (Kalberla et al. 2005). The PC mode spectrum has a photon index of 1.89 (+0.16, -0.15) and a best-fitting absorption column of 4.9 (+0.9, -0.8) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.8 x 10^-11 (7.8 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 4.9 (+0.9, -0.8) x 10^21 cm^-2 Galactic foreground: 1.2 x 10^21 cm^-2 Excess significance: 7.3 sigma Photon index: 1.89 (+0.16, -0.15) If the light curve continues to decay with a power-law decay index of 1.10, the count rate at T+24 hours will be 0.023 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.1 x 10^-12 (1.8 x 10^-12) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00563213. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15019 SUBJECT: GRB 130722A: Enhanced Swift-XRT position DATE: 13/07/22 21:53:25 GMT FROM: Phil Evans at U of Leicester P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team. Using 6812 s of XRT Photon Counting mode data and 11 UVOT images for GRB 130722A, 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 = 260.65190, -2.97283 which is equivalent to: RA (J2000): 17h 22m 36.46s Dec (J2000): -02d 58' 22.2" with an uncertainty of 1.4 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: 15021 SUBJECT: GRB 130722A: MITSuME Okayama upper limits DATE: 13/07/23 00:58:08 GMT FROM: Daisuke Kuroda at OAO/NAOJ D. Kuroda, K. Yanagisawa, Y. Shimizu, H. Toda (OAO, NAOJ), S. Nagayama (NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto) and N. Kawai(Tokyo Tech) report on behalf of MITSuME collaboration: We observed the field of GRB 130722A (Troja et al., GCNC 15013) with the optical three color (g', Rc and Ic) CCD camera attached to the MITSuME 50cm telescope of Okayama Astrophysical Observatory. The observation started on 2013-07-22 11:15:06 UT (~2.9 h after the burst). We could not detect the previously reported afterglow (Melandri et al., GCNC 15015; Trotter et al., GCNC 15017) in all the three bands. Three sigma upper limits of the OT are listed below. We used GSC 2.3 catalog for flux calibration. #T0+[day] MID-UT T-EXP[sec] g' Rc Ic ----------------------------------------------------- 0.23056 13:51:20 9000.0 >18.7 >18.8 >18.3 ----------------------------------------------------- T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15022 SUBJECT: GRB 130722A: Swift/UVOT Detection DATE: 13/07/23 02:38:51 GMT FROM: Frank Marshall at GSFC F. E. Marshall (NASA/GSFC) and E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 130722A 120 s after the BAT trigger (Troja et al., GCN Circ. 15013). A decaying source consistent with the optical position (Melandri et al. GCN Circ. 15015) is detected in the initial UVOT exposures. As noted by Melandri et al., there is a catalogued source near the position of the optical afterglow. The magnitudes and uncertainties reported below have been adjusted to accommodate the possibility that the nearby source accounts for all or none of the UVOT count rate observed at late times. The preliminary UVOT position is: RA(J2000) = 17:22:36.47 = 260.65196 DEC(J2000) = -02:58:21.6 = -2.97268 with an estimated uncertainty of 0.7 arcsec (radius, 90% confidence). The uncertainty has been adjusted slightly due to the possible contamination of the nearby source by up to 10%. The preliminary detection 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_FC 120 270 147 19.6 (+0.12/-0.20) v 4209 5844 393 >19.7 b 3594 17728 2039 >20.9 u 332 16943 2059 >21.0 w1 4619 16030 1218 >21.2 w2 4004 5640 393 >21.3 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.63 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15023 SUBJECT: Konus-Wind observation of GRB 130722A DATE: 13/07/23 07:54:01 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline, on behalf of the Konus-Wind team, report: The long-duration GRB 130722A (Swift-BAT trigger 563213: Troja, et al., GCN 15013) triggered Konus-Wind at T0=30001.378 s UT (08:20:01.378). The light curve from ~T0-6 s to ~T0+55 s shows two main emission pulses peaked at ~T0+1 s and ~T0+31 s, respectively. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB130722_T30001/ As observed by Konus-Wind, the burst had a fluence of (2.35 ± 0.12)x10-5 erg/cm2, and a 64-ms peak flux, measured from T0+0.256s, of (1.84 ± 0.22)x10-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The 3-channel time-integrated spectrum (measured from T0-6.663 to T0+55.191 s) can be modeled, in the 20 keV - 1.35 MeV range, by cutoff power law with the following model parameters: the photon index alpha = -0.92 ± 0.03 and the peak energy Ep = 179 ± 5 keV, The spectrum at the maximum count rate (measured from T0 to T0+8.448 s) is best fit, in the 20 keV - 5 MeV range, by cutoff power law with the following model parameters: the photon index alpha = -0.76 ± 0.12 and the peak energy Ep = 219 ± 15 keV, chi2 = 90.3/76 d.o.f. All the quoted results are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15057 SUBJECT: GRB 130722A: RATIR Optical Observations DATE: 13/07/29 05:13:38 GMT FROM: Owen Littlejohns at Az State U Owen Littlejohns (ASU), Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB) J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UCSC), Eleonora Troja (GSFC), Enrico Ramirez-Ruiz (UCSC), José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 130722A (Melandri, et al., GCN 15013) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir from 2013/07 23.23 to 2013/07 23.39 UTC (21.24 to 25.00 hours after the BAT trigger), obtaining a total of 2.33 hours exposure in the i' band. We detect the candidate GRB host galaxy from Melandri et al. (GCN 15015) noting also that the source is extended. In comparison with USNO-B1, we obtain: i' 19.58 +/- 0.02 This magnitude is in the AB system and not corrected for Galactic extinction in the direction of the GRB. We do not detect the candidate OT, although it is likely blended with the host galaxy. In comparison with the Faulkes measurement one night earlier, the OT has thus faded by at least 1.5 magnitudes. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir.