//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8782 SUBJECT: GRB 090107: Swift detection of a burst DATE: 09/01/07 05:00:06 GMT FROM: David Palmer at LANL T. N. Ukwatta (GSFC/GWU), J. R. Cummings (NASA/UMBC), N. Gehrels (NASA/GSFC), C. Guidorzi (U Ferrara), S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU), W.B Landsman (GSFC), D. M. Palmer (LANL), M. Perri (ASDC) and G. Stratta (ASDC) report on behalf of the Swift Team: At 04:48:04 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 090107 (trigger=339295). Swift could not slew to this burst due to its proximity to the Sun. The BAT on-board calculated location is RA, Dec 302.426, +4.727 which is RA(J2000) = 20h 09m 42s Dec(J2000) = +04d 43' 39" 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 25 sec, with a possible additional peak at T+75 sec. The peak count rate was ~2000 counts/sec (15-350 keV), at ~0 sec after the trigger. Due to the Sun observing constraint, Swift cannot slew to the BAT position. There will thus be no XRT or UVOT data for this trigger. Burst Advocate for this burst is T. N. Ukwatta (tilan.ukwatta AT gmail.com). 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: 8783 SUBJECT: GRB 090107: Swift-BAT refined analysis DATE: 09/01/07 13:51:47 GMT FROM: Scott Barthelmy at NASA/GSFC G. Sato (ISAS), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), 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-240 to T+962 sec from recent telemetry downlinks, we report further analysis of BAT GRB 090107 (trigger #339295) (Ukwatta, et al., GCN Circ. 8782). The BAT ground-calculated position is RA, Dec = 302.409, 4.744 deg, which is RA(J2000) = 20h 09m 38.2s Dec(J2000) = +04d 44' 37.9" with an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 74%. The mask-weighted light curve shows two peaks. The first is about 1.2 sec wide and peaks at ~T+0.9 sec. The second is about 6 sec wide and peaks at ~T+11 sec. Because of the Sun observing constraint and because of a regular pre-planned target slew, the BAT has no data on this event past T+260 sec, until the next orbit. T90 (15-350 keV) is 12.2 +- 0.7 sec (estimated error including systematics). The time-averaged spectrum from T+0.2 to T+12.9 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.69 +- 0.27. The fluence in the 15-150 keV band is 2.3 +- 0.5 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+0.30 sec in the 15-150 keV band is 1.1 +- 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/339295/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8794 SUBJECT: GRB 090107B: Suzaku WAM observation of the prompt emission DATE: 09/01/10 14:30:59 GMT FROM: Yujin E. Nakagawa at RIKEN Y. E. Nakagawa, T. Tamagawa (RIKEN), H. Hayashi, E. Sonoda, M. Yamauchi, H. Tanaka, R. Hara, N. Ohmori, K. Kono (Univ. of Miyazaki), A. Endo, M. Tashiro, Y. Terada, Y. Urata, K. Onda, N. Kodaka, K. Morigami, T. Sugasahara, W. Iwakiri (Saitama U.), T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo), S. Sugita, K. Yamaoka (Aoyama Gakuin U.), M. Ohno, M. Kokubun, M. Suzuki, T. Takahashi (ISAS/JAXA), Y. Hanabata, T. Uehara, T. Takahashi, Y. Fukazawa, C. Kira (Hiroshima U.), S. Hong (Nihon U.), on behalf of the Suzaku WAM team, report: The long GRB 090107B (Gotz et al., GCN 8786) was detected by the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 2009-01-07 16:20:35 UT (=T0). The observed light curve shows a double-peaked structure lasting from T0-1 s to T0+20 s with a duration (T90) of about 14 seconds. The fluence in 100 - 1000 keV was 1.3 (+0.7, -0.9) * 10^-6 erg/cm^2. The 1-s peak flux measured from T0+13 s was 0.4 +/- 0.3 photons/cm^2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0-1 s to T0+20 s is well fitted by a single power-law with a photon index of 2.0 +/- 0.4 (chi^2/d.o.f = 6/10). All the quoted errors are at statistical 90% confidence level, in which the systematic uncertainties are not included. The light curves with 1-sec time resolution for this burst will be appeared at: http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/untrig/grb_table.html