//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10712 SUBJECT: GRB 100504A: Swift detection of a burst DATE: 10/05/04 20:29:03 GMT FROM: Jamie A. Kennea at PSU/Swift-XRT J. Mao (INAF-OAB), S. D. Barthelmy (GSFC), D. N. Burrows (PSU), A. de Ugarte Postigo (INAF-OAB), J. M. Gelbord (PSU), S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA), F. E. Marshall (NASA/GSFC), P. T. O'Brien (U Leicester), D. M. Palmer (LANL), P. Romano (INAF-IASFPA), B. Sbarufatti (INAF-OAB/IASFPA), M. H. Siegel (PSU), M. Stamatikos (OSU/NASA/GSFC), G. Tagliaferri (INAF-OAB) and E. Troja (NASA/GSFC/ORAU) report on behalf of the Swift Team: At 19:20:59 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 100504A (trigger=421124). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 255.572, -35.599 which is RA(J2000) = 17h 02m 17s Dec(J2000) = -35d 35' 55" 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 30 sec. The peak count rate was ~2500 counts/sec (15-350 keV), at ~0 and ~10 sec after the trigger. The XRT began observing the field at 19:22:02.1 UT, 62.6 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source located at RA, Dec 255.57053, -35.58712 which is equivalent to: RA(J2000) = 17h 02m 16.93s Dec(J2000) = -35d 35' 13.6" with an uncertainty of 4.1 arcseconds (radius, 90% containment). This location is 42 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 3.61e+21 cm^-2 (Kalberla et al. 2005). The initial flux in the 2.5 s image was 5.58e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 71 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. Because of the density of catalogued stars, further analysis is required to report an upper limit for any afterglow in the sub-image. The coverage of the XRT error circle by the 8'x8' region for the list of sources generated on-board is uncertain because the large number of sources filled the available telemetry. Because of the density of catalogued stars, further analysis is required to report an upper limit for any afterglow in the region. No correction has been made for the large, but uncertain extinction expected. Burst Advocate for this burst is J. Mao (jirong.mao AT brera.inaf.it). 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: 10713 SUBJECT: GRB 100504A: UVOT-enhanced XRT position DATE: 10/05/04 20:33:23 GMT FROM: Jirong Mao at INAF-OAB J. Mao (INAF-OAB) reports on behalf of the Swift-XRT team: The Swift-XRT observation of GRB 100504A started on 2010 May 4 at 19:22:02.1 UT, 62.6 s after the BAT trigger. We detected a bright, single X-ray source. The UVOT-enhanced position is: RA (J2000): 17h 02m 17.22s Dec (J2000): -35d 35' 14.4'' with an uncertainty of 2.2 arcsec (radius, 90% confidence). This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10715 SUBJECT: GRB 100504A: SARA-South Upper Limit DATE: 10/05/05 02:31:36 GMT FROM: Adria C. Updike at Clemson U Adria C. Updike and Dieter H. Hartmann (Clemson University) report: We observed the field of GRB 100504A (Mao et al., GCN 10712) using the 0.6m SARA-South telescope located at CTIO under good conditions and high airmass beginning 6 hours and 42 min after the trigger. We do not detect a new source at the location of the UVOT-enhanced XRT position (Mao, GCN 10713) to a limiting magnitude of R = 20 mag (on comparison to the USNO B1.0 catalog). We note that the extinction at this galactic latitude is significant; E(B-V) = 0.840 mag (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10716 SUBJECT: GRB 100504A: Swift-BAT refined analysis DATE: 10/05/05 04:01:19 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), H. A. Krimm (GSFC/USRA), J. Mao (INAF-OAB), C. B. Markwardt (GSFC/UMD), T. Sakamoto (GSFC/UMBC), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+363 sec from the recent telemetry downlink, we report further analysis of BAT GRB 100504A (trigger #421124) (Mao, et al., GCN Circ. 10712). The BAT ground-calculated position is RA, Dec = 255.575, -35.590 deg, which is RA(J2000) = 17h 02m 18.1s Dec(J2000) = -35d 35' 23.0" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 92%. The mask-weighted light curve shows two overlapping peaks followed by a weak third peak, starting at ~T-10 sec, peaking at T+0, T+8, and ~T+90 sec, and ending at ~T+100 sec. T90 (15-350 keV) is 97.3 +- 7.3 sec (estimated error including systematics). The time-averaged spectrum from T-9.7 to T+102.2 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.76 +- 0.10. The fluence in the 15-150 keV band is 2.4 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+7.60 sec in the 15-150 keV band is 1.7 +- 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/421124/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10717 SUBJECT: GRB 100504A: GROND Upper limits DATE: 10/05/05 05:09:43 GMT FROM: Felipe Olivares Estay at MPE P. Schady, F. Olivares, R. Filgas and J. Greiner (MPE Garching) report on behalf of the GROND team: We observed the field of GRB 100504A (Swift trigger 421124; Mao et al., GCN #10712) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP, 120, 405) mounted at the 2.2 m MPI/ESO telescope at La Silla Observatory (Chile). Observations started at 01:30 UT on May 5 (about 6.2 hours after the GRB trigger). They were performed at a high airmass. We do not detect a source within the Swift UVOT-enhanced XRT error circle (Mao et al. GCN #10713) in any of the GROND filters. Coadded images of 24 min of integration in g'r'i'z' and 20 min in JHK yield the following 3-sigma upper limits: g' > 23.2 r' > 22.2 i' > 21.6 z' > 21.2 J > 19.4 H > 19.1 K > 18.9 We note the presence of two uncatalogued sources 3" North-West of the enhanced XRT position with magnitudes r' = 19.8 and J = 18.0 for the more southern of the two, and r' = 20.2 and J = 18.6 for the second source. Observations are continuing. All magnitudes given above are in the AB system and are based on the GROND zeropoints and 2MASS field stars. No correction has been applied for the large, uncertain Galactic foreground extinction corresponding to a reddening of E_(B-V)~ 0.8 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10718 SUBJECT: GRB 100504A: Enhanced Swift-XRT position DATE: 10/05/05 06:41:50 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 1124 s of XRT Photon Counting mode data and 3 UVOT images for GRB 100504A, 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 = 255.57137, -35.58742 which is equivalent to: RA (J2000): 17h 02m 17.13s Dec (J2000): -35d 35' 14.7" with an uncertainty of 2.4 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: 10719 SUBJECT: GRB 100504A: Swift-XRT refined analysis DATE: 10/05/05 07:34:12 GMT FROM: Jirong Mao at INAF-OAB J. Mao (INAF-OAB) reports on behalf of the Swift-XRT team: We have analysed 8.7 ks of Swift XRT data for GRB 100504A (Mao et al. GCN Circ. 10712). The data comprise 120 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The light curve shows evidence of flaring in WT mode, peaking at about 83 s, after that, the light curve can be modelled with a broken power-law in PC mode, with an initial decay index of alpha1=3.04(+/-0.57) and breaking to a decay of index alpha2=0.57(+/-0.06), the break time is about 450 s. A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.95 (+/-0.09). The best-fitting absorption column is 9.07 (+/-0.71) x 10^21 cm^-2, in excess of the Galactic value of 3.77 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 5.96 x 10^-11 (9.31 x 10^-11) erg cm^-2 count^-1. The spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.40 (+/-0.37) and the absorption column density is consistent with the Galactic one in the GRB direction. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 5.56 x 10^-11 (6.72 x 10^-11) erg cm^-2 count^-1. 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 6.9 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.8 x 10^-13 (4.6 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/00421124. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10721 SUBJECT: GRB 100504A: Swift/UVOT Observations DATE: 10/05/05 21:46:28 GMT FROM: Mike Siegel at PSU/Swift MOC M. H. Siegel (PSU) and J. Mao (INAF-OAB) report on behalf of the Swift/UVOT team. The Swift/UVOT began settled observations of the field of GRB 100504A 72s after the BAT trigger (Mao et al., GCN Circ. 10712). Data summed from the first and second orbits do not reveal a source at the enhanced position of the X-ray afterglow (Mao et al., GCN Circ. 10713). The 3-sigma upper limits for the finding chart (fc) and summed exposures are reported below: FILTER T_start(s) T_stop Exposure Mag/3UL ======================================================== white fc 72 222 147 >20.39 white 73 1705 391 >20.91 v 614 1755 136 >18.54 b 713 1680 97 >19.35 u 1463 1816 45 >18.43 uvw1 836 1804 97 >18.92 uvw2 762 1037 38 >18.43 ======================================================= The above magnitudes are not corrected for the Galactic extinction corresponding to a reddening of E_{B-V} = 0.87 (Schlegel et al., 1998, ApJS, 500, 525). The photometry is on the UVOT photometric system described in Poole et al. (2008, MNRAS, 383, 627). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10723 SUBJECT: GRB 100504A: Fermi GBM observation DATE: 10/05/06 17:10:53 GMT FROM: Vandiver Chaplin at UAH/Fermi-GBM V.Chaplin (UAH) reports on behalf of the Fermi GBM Team: "At 19:20:55.53 UT on 04 May 2010, the Fermi Gamma-ray Burst Monitor (GBM) triggered on GRB 100504A (trigger 294693657 / 100504.806), which was also seen by Swift,BAT (J.Mao et al., GCN 10712). The calculated GBM ground position is consistent with the Swift,BAT position. The angle from the Fermi LAT boresight is 104 degrees. The GBM light curve shows a single pulse with a duration (T90) of about 16 s (50-300 keV). The time-averaged spectrum from T0-6.1 to T0+23.6 s is best fit by a power-law with an exponential high-energy cutoff. The power-law index is -0.82 (+0.17/-0.16), and the cutoff energy, parameterized as Epeak, is 85.7 (8.0/-6.6) keV (C-stat 960.7 for 481 DOF). The fluence (10-1000 keV) in this time interval is (2.7 +/- 0.12)E-06 erg/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10740 SUBJECT: GRB100504A: Optical upper limits at IAO DATE: 10/05/11 19:22:31 GMT FROM: Daisuke Kuroda at OAO/NAOJ D. Kuroda (OAO, NAOJ), H. Hanayama, T. Miyaji, J. Watanabe(IAO, NAOJ), K. Yanagisawa (OAO, NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto) and N. Kawai(Tokyo Tech) report on behalf of the MITSuME collaboration: We observed the field of GRB 100504A (Mao et al. GCNC 10712) with the optical three color (g', Rc and Ic) CCD camera attached to the Murikabushi 1m telescope of Ishigakijima Astronomical Observatory. The observation started on 2010-05-04 19:24:11 UT (~3.2 min after the burst). We did not find any new point source within the XRT error circle (Mao GCNC10713; Osborne et al. GCNC 10718) in all the three bands. Three sigma upper limits of the OT are listed below. We used GSC2.3 catalog for flux calibration. T0+[day] MID-UT T-EXP[sec] g' Rc Ic ------------------------------------------------------ 0.00625 19:28:41 480.0 >20.1 >20.1 >18.3 ------------------------------------------------------ T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec]