//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15059 SUBJECT: GRB 130803A: Swift detection of a burst DATE: 13/08/03 10:13:29 GMT FROM: David Palmer at LANL K. L. Page (U Leicester), F. E. Marshall (NASA/GSFC), C. J. Mountford (U Leicester), D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the Swift Team: At 10:02:52 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 130803A (trigger=565263). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 220.241, -2.467 which is RA(J2000) = 14h 40m 58s Dec(J2000) = -02d 28' 01" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a double-peaked structure with a duration of about 50 sec. The peak count rate was ~4750 counts/sec (15-350 keV), at ~2 sec after the trigger. The XRT began observing the field at 10:04:22.8 UT, 90.3 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 220.25472, -2.49296 which is equivalent to: RA(J2000) = 14h 41m 01.13s Dec(J2000) = -02d 29' 34.7" with an uncertainty of 4.7 arcseconds (radius, 90% containment). This location is 105 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 in excess of the Galactic value (4.16 x 10^20 cm^-2, Kalberla et al. 2005), with an excess column of 7 (+6.70/-4.79) x 10^21 cm^-2 (90% confidence). UVOT took a finding chart exposure of 150 seconds with the White filter starting 93 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 none of the XRT error circle. 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 0.05. Burst Advocate for this burst is K. L. Page (kpa AT star.le.ac.uk). 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: 15061 SUBJECT: GRB 130803A: Faulkes Telescope South Observations DATE: 13/08/03 14:18:21 GMT FROM: Andrea Melandri at INAF-OAB A. Melandri (INAF/OAB), C. Guidorzi (U. Ferrara) and C. G. Mundell (LJMU) report on behalf of a large collaboration: Tha Faulkes Telescope South robotically observed the field of GRB 130803A starting ~ 2.9 minutes after the Swift trigger (Page et al., GCN 15059). We find no credible afterglow candidate in the XRT error circle. We estimate a 3 sigma upper limit of R>20.0 (texp=30s) ~3.5 minutes and I>21.9 (texp=700s) ~40 minutes after the burst. Magnitudes are calibrated against nearby USNOB-1 stars. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15062 SUBJECT: GRB 130803A: Enhanced Swift-XRT position DATE: 13/08/03 17:56:56 GMT FROM: Phil Evans at U of Leicester J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team. Using 2053 s of XRT Photon Counting mode data and 4 UVOT images for GRB 130803A, 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 = 220.25273, -2.49195 which is equivalent to: RA (J2000): 14h 41m 0.66s Dec (J2000): -02d 29' 31.0" 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: 15063 SUBJECT: GRB 130803A, Swift-BAT refined analysis DATE: 13/08/03 19:03:46 GMT FROM: Jay R. Cummings at NASA/GSFC/Swift GRB 130803A, Swift-BAT refined analysis J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL), T. Sakamoto (AGU), G. Sato (ISAS), 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 130803A (trigger #565263) (Page, et al., GCN Circ. 15059). The BAT ground-calculated position is RA, Dec = 220.256, -2.499 deg which is RA(J2000) = 14h 41m 01.4s Dec(J2000) = -02d 29' 58" with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 30%. The mask-weighted light curve shows two well-separated symmetrical peaks. The first, larger peak starts at about T0-2 seconds and lasts until about T+8 seconds. The second peak, which was softer, starts about T0+41 seconds and lasts until about T0+48 seconds. T90 (15-350 keV) is 44 +- 2 sec (estimated error including systematics). The time-averaged spectrum from T-1.24 to T+45.76 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.69 +- 0.14. The fluence in the 15-150 keV band is 1.5 +- 0.1 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+2.09 sec in the 15-150 keV band is 5.1 +- 0.4 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/565263/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15064 SUBJECT: GRB 130803A; Fermi GBM observation DATE: 13/08/04 00:35:04 GMT FROM: Hoi-Fung Yu at MPE Subject: GRB 130803A: Fermi GBM observation Hoi-Fung Yu (MPE) report on behalf of the Fermi GBM Team: "At 10:02:53.75 UT on 03 Aug 2013, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 130803A (trigger 397216976 / 130803419), which was also detected by the Swift BAT and XRT (Page et al. 2013, GCN 15059). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight is 86 degrees. The GBM light curve consists of a single pulse, with a duration (T90) of about 7.6 s (50-300 keV). The time-averaged spectrum from T0-1.0 s to T0+4.9 s is adequately fit by a power law function with an exponential high-energy cutoff. The power-law index is -0.85 +/- 0.09 and the cutoff energy, parameterized as Epeak, is 141.6 +/- 12.2 keV. The event fluence (10-1000 keV) in this time interval is (2.5 +/- 0.1)E-6 erg/cm^2. The 1-sec peak photon flux measured starting from T0+0.6 s in the 10-1000 keV band is 7.1 +/- 0.3 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: 15065 SUBJECT: GRB 130803A: Swift/UVOT Upper Limits DATE: 13/08/04 02:09:13 GMT FROM: Frank Marshall at GSFC F. E. Marshall (NASA/GSFC) and K. L. Page (U. Leicester) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 130803A 93 s after the BAT trigger (Page et al., GCN Circ. 15059). No optical afterglow consistent with the enhanced XRT position (Osborne et al. GCN Circ. 15062) 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) exposures and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 93 243 147 >21.0 u_FC 305 555 246 >20.3 white 93 6186 560 >21.7 v 636 11010 1142 >20.8 b 561 5981 413 >21.0 u 305 5776 639 >20.7 w1 3936 16308 788 >21.4 m2 5167 11916 1082 >21.2 w2 4757 6392 393 >20.9 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.05 in the direction of the burst //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15066 SUBJECT: GRB130803A: GROND detection of possible host DATE: 13/08/04 05:53:17 GMT FROM: Karla Varela at MPE K.Varela (MPE Garching), P.Afonso (American River College) and J.Greiner (MPE Garching)report on behalf of the GROND team : We observed the field GRB 130803A (Swift trigger 565263; Page et al., GCN 15059) simultaneously in g'r'i'z'JHKs with GROND (Greiner et al.2008, PASP 120, 405) mounted at the 2.2m MPG/ESO telescope at La Silla Observatory (Chile). Observations started at 23:13 UT on August 3, about 13.2 hours after the trigger at a mean seeing of 1.8 arcsec and a mean airmass of 1.3. We detect an extended source inside the enhanced 1.4'' XRT error circle (Swift webpage). This could be the GRB host, though at the moment no statement about variability can be made. For stacked integration times of 100 min. in JHK and ~ 125min in griz, we present the following preliminary magnitudes and ULs at the 3 sigma level: g' = 25.6 +/- 0.4 mag, r' = 24.4 +/- 0.3 mag, i' = 23.8 +/- 0.2 mag, z' = 23.4 +/- 0.3 mag, J > 23.2 mag, H > 22.5 mag, and K > 22.2 mag. Given magnitudes are calibrated against GROND zeropoints as well as 2MASS field stars and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E(B-V) = 0.05 mag in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15067 SUBJECT: GRB 130803A: RATIR Optical and NIR Observations DATE: 13/08/04 07:00:59 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 130803A (Page, et al., GCN 15059) 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 2013/08 4.15 to 2013/08 4.25 UTC (17.51 to 19.98 hours after the BAT trigger), obtaining a total of 1.53 hours exposure in the r' and i' bands and 0.63 hours exposure in the Z, Y, J, and H bands. For a source within the Swift-XRT error circle, in comparison with SDSS DR9 and 2MASS, we obtain the following upper limits (3-sigma): r' > 23.29 i' > 23.24 Z > 22.27 Y > 21.70 J > 20.90 H > 20.24 These magnitudes are in the AB system and not corrected for Galactic extinction in the direction of the GRB. Our upper limits are consistent with the detections and upper limits reported by Varela, et al. (GCN 15066). We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15068 SUBJECT: GRB 130803A: Swift-XRT refined Analysis DATE: 13/08/04 09:13:24 GMT FROM: Phil Evans at U of Leicester A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), B.P. Gompertz (U. Leicester), B. Sbarufatti (INAF-OAB/PSU), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), J.A. Kennea (PSU), V. Mangano (PSU), M.C. Stroh (PSU) and K.L. Page report on behalf of the Swift-XRT team: We have analysed 10 ks of XRT data for GRB 130803A (Page et al. GCN Circ. 15059), from 75 s to 61.7 ks after the BAT trigger. The data comprise 7 s in Windowed Timing (WT) mode (taken while Swift was slewing), with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN. Circ 15062). The late-time light curve (from T0+3.9 ks) can be modelled with a power-law decay with a decay index of alpha=0.87 (+/-0.09). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.40 (+0.24, -0.23). The best-fitting absorption column is 8.7 (+1.6, -1.4) x 10^21 cm^-2, in excess of the Galactic value of 4.2 x 10^20 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.5 x 10^-11 (1.3 x 10^-10) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 8.7 (+1.6, -1.4) x 10^21 cm^-2 Galactic foreground: 4.2 x 10^20 cm^-2 Excess significance: 9.7 sigma Photon index: 2.40 (+0.24, -0.23) If the light curve continues to decay with a power-law decay index of 0.87, the count rate at T+24 hours will be 9.6 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.3 x 10^-13 (1.2 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/00565263. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15073 SUBJECT: GRB130803A: GROND observations DATE: 13/08/06 10:32:42 GMT FROM: Karla Varela at MPE K. Varela (MPE Garching), M. Tanga (MPE Garching), P. Afonso (American River College) and J. Greiner (MPE Garching) report on behalf of the GROND team: We observed a second epoch of the field of GRB 130803A (Swift trigger 565263; Page et al., GCN 15059) simultaneously in g'r'i'z'JHKs with GROND (Greiner et al.2008, PASP 120, 405) mounted at the 2.2m MPG/ESO telescope at La Silla Observatory (Chile). Observations started at 23:34 UT on August 5, about 61.7 hours after the trigger at a mean seeing of 1.5 arcsec and a mean airmass of 1.3. We confirm the detection of the source inside the enhanced 1.4'' XRT error circle (Swift webpage) reported in a previous GCN (Varela et al., GCN15066), and measure consistent magnitudes as compared to the first epoch (the g'-band magnitude contained an error and should read g' = 24.6 +/- 0.4). Thus, we consider this source as the potential host of GRB 130803A.