//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14530 SUBJECT: GRB 130502B: Fermi GBM detection of a burst DATE: 13/05/02 20:15:24 GMT FROM: George A. Younes at USRA/NASA/MSFC A. Von Kienlin (MPE) and G. Younes (NASA/USRA) report on behalf of the Fermi GBM Team: "At 07:51:11.76 UT on May 2 2013, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 130502B (trigger 389173874 / 130502327). The on-ground calculated location, using the GBM trigger data, is RA = 74.5, DEC = 70.6 (J2000 degrees), with an uncertainty of 1.0 degree (radius, 1-sigma containment, statistical only; there is additionally a systematic error which is currently estimated to be 2 to 3 degrees). The angle from the Fermi LAT boresight is 47 degrees. This burst was also independently detected by INTEGRAL SPI-ACS. The GBM light curve consists of multiple spikes with a duration (T90) of about 24 s (50-300 keV). The time-averaged spectrum from T0-4.1 s to T0+71.7 s is best fit by a Band function with Epeak = 323.00 +/- 7.00 keV, alpha = -0.75 +/- 0.01, and beta = -2.47 +/- 0.07. The event fluence (10-1000 keV) in this time interval is (1.21 +/- 0.01)E-04 erg/cm^2. The 1.024 sec peak photon flux measured starting from T0+30.3 s in the 8-1000 keV band is 45.8 +/- 0.5 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog." [GCN OPS NOTE(02may13): The "April" in the first sentence was changed to "May".] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14532 SUBJECT: GRB 130502B: Fermi LAT Detection DATE: 13/05/02 21:50:17 GMT FROM: Daniel Kocevski at SLAC GRB 130502B: Fermi-LAT detection of a burst D. Kocevski (NASA/GSFC), G. Vianello (Stanford), J. Chiang (SLAC), J. Racusin (NASA/GSFC), and E. Troja (CRESST) report on behalf of the Fermi-LAT team: At 07:51:11 UT on 2nd May 2013, Fermi-LAT detected high energy emission from GRB 130502B, which was also detected by Fermi-GBM (trigger 389173874/130502327) (GCN 14530) . The best LAT on-ground location is found to be RA, DEC 66.648, 71.0841 (J2000) with an error radius of 0.093 deg (68% containment, statistical error only), this was about ~45 deg from the LAT boresight at the time of the trigger. The data from the Fermi-LAT show a multi-peaked light curve consistent with the GBM data. More than 100 photons above 100 MeV are observed within 200 seconds with a TS of > 158. The multi-peak structure is clearly seen in the non-standard LAT Low Energy (LLE) data selection, with a significance of ~8 sigma. The highest energy LAT photon consistent with the burst position has an energy of 30 GeV and arrived ~220s after the trigger. A Swift TOO request has been submitted. The Fermi LAT point of contact for this burst is Daniel Kocevski (daniel.kocevski@nasa.gov). The Fermi LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14540 SUBJECT: GRB 130502B Swift-XRT observations DATE: 13/05/03 13:17:58 GMT FROM: Stefan Immler at NASA/GSFC A. Melandri (INAF-OAB) and S. Immler (NASA/CRESST/GSFC) report on behalf of the Swift-XRT team: We have analysed 3.4 ks of XRT data for the Fermi/LAT-detected burst: GRB 130502B, from 55.1 ks to 67.9 ks after the Fermi/LAT trigger. The data are entirely in Photon Counting (PC) mode. An X-ray source is detected within the Fermi/LAT error circle. Using 3614 s of PC mode data and 6 UVOT images, we find an enhanced XRT position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 66.76207, +71.06071 which is equivalent to: RA (J2000): 04h 27m 02.90s Dec(J2000): +71d 03' 38.5" with an uncertainty of 1.5 arcsec (radius, 90% confidence). This position is 157 arcsec from the Fermi/LAT position. The light curve is consistent with a constant source of mean count rate 1.1e-01 ct/sec. A power-law fit gives an index of 0.8 (+/-1.3). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.88 (+0.28, -0.26). The best-fitting absorption column is 2.8 (+1.0, -0.9) 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 4.3 x 10^-11 (6.3 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 2.8 (+1.0, -0.9) x 10^21 cm^-2 Galactic foreground: 1.1 x 10^21 cm^-2 Excess significance: 3.1 sigma Photon index: 1.88 (+0.28, -0.26) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00020266. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14541 SUBJECT: GRB 130502B: P60 Observations DATE: 13/05/03 13:48:50 GMT FROM: S. Bradley Cenko at Caltech S. B. Cenko (UC Berkeley), D. A. Perley, and L. P. Singer (Caltech) report on behalf of a larger collaboration: We imaged the field of the Fermi GBM (Von Kienlin et al., GCN 14530) and LAT (Kocevski et al., GCN 14532) GRB130502B with the robotic Palomar 60 inch telescope. Observations began at 03:34 UT on 3 May 2013 (~ 0.82 d after the GBM trigger) and were obtained under poor seeing conditions. We detect no significant emission at the position of the candidate X-ray afterglow (Melandri et al., GCN 14540). Using nearby point sources from the USNO-B1 catalog for reference, we measure an upper limit of r' > 20.4 mag at this time. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14542 SUBJECT: Konus-Wind observation of GRB 130502B DATE: 13/05/03 14:32:02 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report: The long-duration intense GRB 130502B (Fermi-GBM detection: von Kienlin et al., GCN 14530; Fermi-LAT detection: Kocevski et al., GCN 14532) triggered Konus-Wind at T0=28272.763s UT (07:51:12.763) The light curve shows a bright multi-peaked structure from ~T0 s to ~T0+30s. The emission is seen up to 10 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB130502_T28272/ As observed by Konus-Wind, the burst had a fluence of (1.13 ± 0.04)x10-4 erg/cm2, and a 64-ms peak flux, measured from T0+29.944s, of (1.81 ± 0.08)x10-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum (measured from T0 to T0+27.392 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.84 ± 0.04, the high energy photon index beta = -2.7 ± 0.1, the peak energy Ep = 293 ± 9 keV, chi2 = 107/91 dof. The spectrum at the maximum count rate (measured from T0+26.624 to T0+27.392 s) is best fit in the 20 keV - 15 MeV range by the cutoff power law with the following model parameters: the photon index alpha = -0.81 ± 0.06, the peak energy Ep = 264 ± 14 keV, chi2 = 104/93 dof. All the quoted results are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14544 SUBJECT: GRB 130502B: Swift/UVOT Upper Limits DATE: 13/05/03 15:09:16 GMT FROM: Alice Breeveld at MSSL-UCL A. A. Breeveld (MSSL-UCL) and S. Immler (NASA/CRESST/GSFC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 130502B 55101 s after the LAT trigger (Kocevski et al., GCN Circ. 14532). No optical afterglow consistent with the refined XRT position (Melandri et al., GCN Circ. 14540) is detected in the UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 55101 55208 105 >20.3 white 55101 89746 4493 >22.1 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.21 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14546 SUBJECT: IPN Triangulation of GRB 130502B DATE: 13/05/03 19:38:51 GMT FROM: Kevin Hurley at UCBerkeley/SSL K. Hurley and J. Goldsten, on behalf of the MESSENGER NS GRB team, S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, D. M. Smith, on behalf of the RHESSI GRB team, A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, K. Yamaoka, M. Ohno, Y. Hanabata, Y. Fukazawa, T. Takahashi, M. Tashiro, Y. Terada, T. Murakami, and K. Makishima on behalf of the Suzaku WAM team, S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer, on behalf of the Swift-BAT team, E. Del Monte, I. Donnarumma, Y. Evangelista, M. Feroci, I. Lapshov, F. Lazzarotto, and M. Marisaldi, on behalf of the AGILE Team, and V. Connaughton, M. S. Briggs, C. Meegan, and V. Pelassa, on behalf of the Fermi GBM team, report: GRB 130502B (von Kienlin et al., GCN 14530, Kocevski et al., GCN 14532, Golenetskii et al., GCN 14542) has been observed by AGILE MCAL, Fermi GBM, INTEGRAL (SPI-ACS), Konus-Wind, MESSENGER (GRNS), RHESSI, Suzaku WAM, and Swift BAT (outside the coded field of view), so far. We have triangulated it to a long, narrow error box which reduces the size of the LAT (statistical-only) error circle (GCN 14532) and produces the following error box: RA(2000) DEC(2000) CENTER: 66.6391 deg = 04 h 26 m 33 s 71.0809 deg = 71 d 04 ' 51 " CORNERS: 66.8800 deg = 04 h 27 m 31 s 71.0295 deg = 71 d 01 ' 46 " 66.4487 deg = 04 h 25 m 48 s 71.1511 deg = 71 d 09 ' 04 " 66.8267 deg = 04 h 27 m 18 s 71.0114 deg = 71 d 00 ' 41 " 66.4008 deg = 04 h 25 m 36 s 71.1314 deg = 71 d 07 ' 53 " The area of this box is about 17 square arcminutes, and it contains the Swift-XRT source (Melandri et al., GCN 14540). Maps have been posted at ssl.berkeley.edu/ipn3/130502 The triangulation can be improved. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14552 SUBJECT: GRB 130502B: possible TNG counterpart DATE: 13/05/04 09:19:10 GMT FROM: Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst D. Malesani (DARK/NBI), P. D'Avanzo (INAF/OABr), S. Covino (INAF/OABr), A. Melandri (INAF/OABr), V. D'Elia (INAF/OAR and ASI/ASDC), S. Campana (INAF/OABr), D. Fugazza (INAF/OABr), G. Tagliaferri (INAF/OABr), B. Blu, L. Di Fabrizio (INAF/FGG), C. P. Padilla-Torres (INAF/FGG), report on behalf of the CIBO collaboration: We observed the field of the LAT-detected GRB 130502B (Von Kienlin & Younes, GCN 14530; Kocevski et al., GCN 14532; Golenetskii et al., GCN 14542) with the TNG equipped with the DOLoRes imager. Observations were carried out starting on 2013 May 3.872 UT (1.54 days after the trigger), for a total of 30 min on source in the R band, at a high airmass of around 2.2. The seeing was 1.2". No bright object is detected inside the X-ray error circle (Melandri & Immler, GCN 14540; see also http://www.swift.ac.uk/xrt_positions/), down to a 3-sigma limit of R = 23.7 (calibration based on several nearby USNO stars). However, a faint flux enhancement is seen consistent with the XRT position, at coordinates (J2000): RA = 04:27:02.82 Dec = +71:03:38.5 A finding chart is shown at http://www.astro.ku.dk/~malesani/GRB/130502B/GRB130502B_finder.jpg We estimate the magnitude of this marginally detected source to be R = 24.7 +- 0.5. At the moment, we have no information about its variability, and it could be either the GRB counterpart or its host galaxy. Last, independently of the reality of the object, this GRB can be classified as dark. Considering the limit R > 23.7, and a Galactic extinction A_V = 0.57 (Schlafly & Finkbeiner 2011, ApJ, 737, 103), the optical-to-X-ray spectral index is beta_OX < 0.47 (if the object is real, then beta_OX = 0.34 +- 0.07). The presence of significant excess column density in the X-ray spectrum (Melandri & Immler, GCN 14540; see also http://www.swift.ac.uk/xrt_spectra/00020266/) suggests an extinguished event. [GCN OPS NOTE(04may13): Per author's request, the URL in the last paragraph was change from the team-internal version to the public version.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14555 SUBJECT: GRB 130502B: Swift-XRT refined Analysis DATE: 13/05/04 13:30:51 GMT FROM: Andrea Melandri at INAF-OAB A. Melandri (INAF-OAB) and S. Immler (NASA/CRESST/GSFC) report on behalf of the Swift-XRT team: We have analysed 8.3 ks of XRT data for the Fermi/LAT-detected burst: GRB 130502B (Kocevski et al. GCN Circ. 14532), from 55.1 ks to 101.8 ks after the Fermi/LAT trigger. The object dectected in the first 3.4 ks of XRT data (Melandri & Immler GCN Circ. 14540) is now clearly fading. The light curve can be modelled with a power-law decay with a decay index of alpha=1.52 (+/-0.25). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.89 (+/-0.20). The best- fitting absorption column is 1.73 (+0.78, -0.71) x 10^21 cm^-2, in addition to 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 4.3 x 10^-11 (6.3 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Galactic foreground: 1.1 x 10^21 cm^-2 Intrinsic column: 1.73 (+0.78, -0.71) x 10^20 cm^-2 Photon index: 1.89 (+0.21, -0.20) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00020266. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14557 SUBJECT: GRB 130502B: Suzaku WAM observation of the prompt emission DATE: 13/05/04 15:15:48 GMT FROM: Makoto Tashiro at Saitama U/Swift T. Yasuda, M. Tashiro, Y. Terada, Y. Ishida, H. Ueno, S. Sugimoto (Saitama U.), M. Ohno, K. Takaki, T. Kawano, R. Nakamura, S. Furui, Y. Fukazawa (Hiroshima U.), M. Yamauchi, N. Ohmori, M. Akiyama (Univ. of Miyazaki), K. Yamaoka (Nagoya U.), S. Sugita (Ehime U.), Y. E. Nakagawa, M. Kokubun, T. Takahashi (ISAS/JAXA), W. Iwakiri(RIKEN), Y. Hanabata (ICRR), Y. Urata (NCU), K. Nakazawa, K. Makishima (Univ. of Tokyo) on behalf of the Suzaku WAM team, report: The bright, long GRB 130502B (Fermi-GBM detection : von Kienlin and Younes, GCN 14530; Fermi-LAT detection : Kocevski et al., GCN 14532) triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 07:51:15.113 UT (=T0). The observed light curve shows a multi-peaked structure starting at T0-2 s, ending at T0+34 s with a duration (T90) of about 24 seconds. The fluence in 100 - 1000 keV was 7.38 (+0.37/-0.29) x10-5 erg/cm^2. The 1-s peak flux measured from T0+22 s was 14.53 (-0.77/+0.73) photons/cm^2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0-2 s to T0+34 s is well fitted by a GRB Band model as follows. the low-energy photon index alpha: -1.04 (+0.49/-0.36), the high-energy photon index beta: -2.73 (+0.10/-0.12), and the peak energy Epeak: 359 (+22/-33) keV (chi^2/d.o.f = 65.7/50). Due to the high flux of this burst, a 3% systematic error was added for low energy channels. All the errors are quoted at 90% confidence level. The light curves for this burst are available at: http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14591 SUBJECT: Refined IPN Triangulation of GRB 130502B DATE: 13/05/06 22:33:41 GMT FROM: Kevin Hurley at UCBerkeley/SSL K. Hurley and J. Goldsten, on behalf of the MESSENGER NS GRB team, S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin, on behalf of the HEND-Odyssey GRB team, W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr, on behalf of the GRS-Odyssey GRB team, D. M. Smith, on behalf of the RHESSI GRB team, A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, K. Yamaoka, M. Ohno, Y. Hanabata, Y. Fukazawa, T. Takahashi, M. Tashiro, Y. Terada, T. Murakami, and K. Makishima on behalf of the Suzaku WAM team, S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer, on behalf of the Swift-BAT team, E. Del Monte, I. Donnarumma, Y. Evangelista, M. Feroci, I. Lapshov, F. Lazzarotto, and M. Marisaldi, on behalf of the AGILE Team, and V. Connaughton, M. S. Briggs, C. Meegan, and V. Pelassa, on behalf of the Fermi GBM team, report: GRB 130502B (von Kienlin et al., GCN 14530, Kocevski et al., GCN 14532, Golenetskii et al., GCN 14542, Hurley et al. 14546) was also observed by Odyssey. Using Odyssey data reduces the size of the previous error box by about a factor of two: RA(2000) DEC(2000) CENTER: 66.714= 4 h 26 m 51 s 71.066= 71 d 03 ' 58 " CORNERS: 66.893= 4 h 27 m 34 s 71.032= 71 d 01 ' 55 " 67.092= 4 h 28 m 21 s 70.975= 70 d 58 ' 29 " 66.334= 4 h 25 m 20 s 71.156= 71 d 09 ' 22 " 66.535= 4 h 26 m 08 s 71.100= 71 d 05 ' 59 " The area of this box is about 8 square arcminutes, and it still contains the Swift-XRT source (Melandri et al., GCN 14540). A new map has been posted at ssl.berkeley.edu/ipn3/130502 Some improvement in this error box is possible.