//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13070 SUBJECT: GBM trigger 353549464 (GRB 120316A?) : High-energy photon emission in Fermi/LAT data DATE: 12/03/19 23:56:20 GMT FROM: Weikang Zheng at U.of Michigan Weikang Zheng and Carl Akerlof report on behalf of the ROTSE collaboration: High-energy photon emission in Fermi/LAT data was found to be correlated with GBM trigger 353549464 (00:11:02 UT on Mar. 16, 2012, probably GRB 120316A) as a follow-up of a routine search in GBM trigger catalogs using our LAT data processing pipeline. The GBM trigger location (RA = 47.93, Dec = -63.09) was about 17 degree from the LAT boresight, and the zenith angle was about 54 degrees. A maximum likelihood analysis gives a TS value of 32.9 over a time window extending to 160s after the trigger. In that time span, more than 10 photons above 100 MeV were detected, with the highest energy of ~1.98 GeV at 27s after the burst. The GRB location estimated by the likelihood analysis is RA = 57.70, Dec = -56.51 with uncertainty ~0.5 degree. This is ~8 degrees away from the GBM trigger location. Our location is consistent with the preliminary IPN error box (GCN in preparation, Hurley & Pal'shin) The photon information can be found in the following link, including the skymap and light curve figures: http://www.rotse.net/LAT/GBMTriggers/353549464/353549464_res.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13073 SUBJECT: IPN Triangulation of GRB 120316A DATE: 12/03/20 14:09:19 GMT FROM: Valentin Pal'shin at Ioffe Inst K. Hurley on behalf of the Mars Odyssey and MESSENGER GRB teams, I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin, on behalf of the HEND-Odyssey 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, V. Connaughton, M. Briggs, and C. Meegan, on behalf of the Fermi GBM team, A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer, on behalf of the Swift-BAT team, and 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, report: The long GRB 120316A was observed by Fermi (GBM: trigger 353549464), INTEGRAL (SPI-ACS), Konus-Wind, Mars Odyssey (HEND), Suzaku (WAM), and Swift (BAT) (outside the coded field of view) at about 662 s UT (00:11:02). We have triangulated it to a preliminary, 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 57.016 (03h 48m 04s) -56.288 (-56d 17' 15") Corners: 56.269 (03h 45m 05s) -57.541 (-57d 32' 28") 57.363 (03h 49m 27s) -57.038 (-57d 02' 16") 57.698 (03h 50m 48s) -55.028 (-55d 01' 42") 56.676 (03h 46m 42s) -55.538 (-55d 32' 18") --------------------------------------------- The error box area is 1.07 sq. deg, and its maximum dimension is 2.6 deg. This box can be improved. The LAT position reported by Zheng & Akerlof (GCN 13070 ) is consistent with the IPN box (the center of this position is outside the box, but the error circle overlaps with the box). The time history and spectrum will be given in a forthcoming GCN Circular. A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB120316_T00672/IPN/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13074 SUBJECT: Konus-Wind observation of GRB 120316A DATE: 12/03/20 14:18:02 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 GRB 120316A (GBM trigger 353549464; Fermi/LAT detection: Zheng & Akerlof, GCN 13070; IPN localization: Hurley at al., GCN 13073) triggered Konus-Wind at T0=00672.966s UT (00:11:12.966) The light curve shows multiple partly overlapped pulses. A total duration of the burst is ~32 s. The emission is seen up to ~8 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB120316_T00672/ As observed by Konus-Wind the burst had a fluence of 2.3(-0.4,+0.5)x10-5 erg/cm2, and a 256-ms peak flux, measured from T0+9.216 s, of 2.5(-0.5,+0.7)x10-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum of the burst (measured from T0 to T0+15.872 s) is best fit in the 20 keV - 10 MeV range by a power law with exponential cutoff model, for which alpha = -0.92 (-0.13, +0.15), and Ep = 539(-109, +167) keV, chi2 = 92/86 dof. All the quoted results are preliminary. All the quoted errors are at the 90% confidence level. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13085 SUBJECT: GRB 120316A: Fermi-GBM and Fermi-LAT Observations DATE: 12/03/21 21:22:59 GMT FROM: Giacomo Vianello at SLAC Giacomo Vianello (CIFS/SLAC), Nicola Omodei (Stanford U.), J. L. Racusin (NASA/GSFC), P. Jenke (MSFC/NPP) report on behalf of the Fermi GBM and LAT Teams: At 00:11:02.56 UT on 16 March 2012, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 120316A (trigger 353549464 / 120316008), which was also detected by Konus-Wind (GCN 13074) and triangulated by the IPN (GCN 13073). The GBM H.I.T.L. location is found to be RA, Dec (J2000) = 48.5, -64.3 with a error radius (90% containment, statistical) of 1.2 degrees. The GBM light curve shows multiple peaks with a duration of T90 = 27.5 +/- 0.4 seconds, and a signal extending to 500 keV in the NaI's and 850 keV in the BGO's. The GRB is barely detected by the LAT, with a Test Statistic slightly below the TS=25 threshold usually adopted for issuing circulars. The best LAT on-ground location is found to be RA,Dec (J2000) = 57.97, -56.46 with an error radius of 0.65 deg (90% containment, statistical error only). This was 9.7 deg from the LAT boresight at the time of the trigger. The LAT position is compatible with that found by Zheng et al. (GCN 13070) and by Hurley et al. (GCN 13073), and is ~9 deg away from the best GBM localization. Modeling of the uncertainties in GBM localizations, using known reference locations, suggests that whilst the majority (>90%) are well-represented by a ~3 deg systematic error, GRB120316A appears to belong to a small tail which has a much larger systematic uncertainty, centered on ~10 deg (see Connaughton et al., in preparation). The spectrum of this GRB from 10 keV to 300 GeV, integrated over the time interval 0-32 s from the trigger time, is well described by a Band function with Epeak = 552 -25 +22 keV, alpha = -0.77 +/- 0.02, beta = -2.90 +/-0.15. The fluence in the 10 keV - 1 MeV energy range is 2.57 ( +/- 0.03 (stat) +/- 0.2 (sys) ) x 10^-5 erg/cm2, compatible with the value found by Golenetskii et al (GCN 13074). The spectral analysis results presented above are preliminary; The Fermi LAT point of contact for this burst is Giacomo Vianello (giacomov@slac.stanford.edu). The GBM point of contact is Peter Jenke (peter.a.jenke@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: 13088 SUBJECT: GRB 120316A : Suzaku WAM observation of the prompt emission DATE: 12/03/23 07:51:49 GMT FROM: Yoshitaka Hanabata at Hiroshima U Y. Hanabata, T. Uehara, T. Kawano, K. Takaki, M. Mizuno, M. Ohno, Y. Fukazawa (Hiroshima U.), W. Iwakiri, M. Tashiro, Y. Terada, T. Yasuda, K. Takahara, M. Asahina, S. Kobayashi, A. Sakamoto (Saitama U.), S. Sugita (Nagoya U.), K. Yamaoka (Aoyama Gakuin U.), M. Kokubun, T. Takahashi (ISAS/JAXA), Y. E. Nakagawa (Waseda U.), N. Ohmori, M. Akiyama, M. Yamauchi (Univ. of Miyazaki), C-J. Chuang, Y. Urata, P. Tsai (NCU), K. Nakazawa, K. Makishima (Univ. of Tokyo), on behalf of the Suzaku WAM team, report: The long GRB 120316A (GBM trigger 353549464; Fermi-LAT detection: Zheng & Akerlof, GCN 13070; IPN localization: Hurley at al., GCN 13073) was detected by the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 00:11:02 UT (=T0). The observed light curve shows a multi-peaked structure starting at T0, ending at T0+28 s with a duration (T90) of about 24 seconds. The fluence in 100 - 1000 keV was 1.79 (-0.49, +0.07) x 10^-5 erg/cm^2. The 1-s peak flux measured from T0+21 s was 2.75 (-1.02, +0.31) photons/cm^2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0 to T0+28 s is well fitted by a GRB Band model as follows. the low-energy photon index alpha: -0.44 (-0.61, +0.89), the high-energy photon index beta: -2.63 (-0.58, +0.31), and the peak energy Epeak: 530 (-76, +89) keV (chi^2/d.o.f = 12.6/12). Due to the brightness of this burst, a 3% systematic error was added for low energy channels. All the quoted errors are at statistical 90% confidence level. The light curves for this burst will be available at: http://www.astro.isas.ac.jp/suzaku/HXD-WAM/WAM-GRB/grb/untrig/grb_table.html