//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9962 SUBJECT: GRB 090929A: Fermi GBM detection DATE: 09/09/29 07:46:14 GMT FROM: Arne Rau at MPE Arne Rau (MPE) report on behalf of the Fermi GBM Team: "At 04:33:03.97 UT on 29 September 2009, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 090929A (trigger 275891585 / 090929190). The on-ground calculated location, using the GBM trigger data, is RA = 51.7, DEC = -7.3 (J2000 degrees, equivalent to 03h 27m, -07d 18'), with an uncertainty of 1.3 degrees (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 122 degrees. This burst was also independently detected by INTEGRAL SPI-ACS. The GBM light curve consists of multiple short peaks with a duration (T90) of about 8.5 +/- 0.4 s (8-1000 keV). The time-averaged spectrum from T0+0.002s to T0+4.896s is best fit by a power law function with an exponential high energy cutoff. The power law index is -0.52 +/- 0.06 and the cutoff energy, parameterized as Epeak, is 610.9 +/- 44.5 keV (chi squared 439 for 393 d.o.f.). The event fluence (8-1000 keV) in this time interval is (1.06 +/- 0.03)E-05 erg/cm^2. The 1.822-sec peak photon flux measured starting from T0+0.002 s in the 8-1000 keV band is 10.9 +/- 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: 9964 SUBJECT: GRB 090929: Enhanced Swift-XRT position DATE: 09/09/29 14:00:14 GMT FROM: Phil Evans at U of Leicester M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team. Using 2438 s of XRT Photon Counting mode data and 2 UVOT images for GRB 090929, 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 = 117.72015, -0.65764 which is equivalent to: RA (J2000): 07h 50m 52.84s Dec (J2000): -00d 39' 27.5" 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: 9966 SUBJECT: GRB 090929A BAT location of the Fermi GBM burst DATE: 09/09/29 14:15:48 GMT FROM: Jay R. Cummings at NASA/GSFC/Swift J. R. Cummings (GSFC/UMBC) and H. Krimm (GSFC/USRA) on behalf of the Swift team The Fermi-GBM burst GRB 090929A (Rau, GCN Circular# 9962) occurred during a preplanned Swift slew maneuver. A strong source was found in a mosaic of images from BAT event data, which is often collected during slews. The source location was RA, Dec = 56.494, -5.952 or RA (J2000) 03h 45m 57.9s Dec (J2000) -05d 57' 50" with an estimated 90% containment error radius of 3 arcmin. The partial coding was 73-90% during the burst. We define the trigger time as 04:33:08 UTC. As seen in BAT, the burst had three progressively weaker peaks, at T+1, T+4, and T+8. The peak count rate (15-350 keV) was ~18000 counts/sec at T+2 sec. T90 was about 10 seconds. A Swift TOO has been requested and approved. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9968 SUBJECT: Konus-RF observation of GRB 090929A DATE: 09/09/29 17:45:37 GMT FROM: Valentin Pal'shin at Ioffe Inst S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, P. Oleynik, M. Ulanov, and D. Svinkin on behalf of the Konus-RF team, report: The bright GRB 090929A (Fermi-GBM trigger trigger 275891585: Rau, GCN 9962) localized by Swift-BAT (Cummings and Krimm , GCN 9966) triggered Konus-RF at T0=16384.747 s UT (04:33:04.747). The burst light curve shows several multipeaked pulses with a total duration of ~6 s. As observed by Konus-RF the burst had a fluence of 1.24(-0.11, +0.12)x10^-5 erg/cm2, and a 16-ms peak flux measured from T0-0.040 s of (2.02 +/- 0.46)x10^-5 erg/cm2/s (both in the 20 keV - 3 MeV energy range). The time-integrated spectrum of the burst (from T0-1.2 to T0+4.5 s) is well fitted (in the 10 keV - 3 MeV range) by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep), with alpha = -0.55(-0.11, +0.12), and Ep = 480(-54, +64) keV (chi2 = 120.1/119 dof). The spectrum accumulated over the burst maximum (from T0-0.2 to T0+0.1 s) is well fitted (in the 10 keV - 3 MeV range) by a power law with exponential cutoff model with alpha = -0.28(-0.14, +0.15), and Ep = 633(-71, +81) keV (chi2 = 44.0/56 dof). Fitting by GRB (Band) model yields the same alpha and Ep, and only an upper limit on the high energy photon index: beta < -3.06 (chi2 = 44.0/55 dof). All the quoted values are preliminary. All the quoted errors are at the 90% confidence level. The Konus-RF light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB090929_T16384/KRF/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9976 SUBJECT: Konus-Wind observation of GRB 090929A DATE: 09/09/30 16:16:53 GMT FROM: Valentin Pal'shin at Ioffe Inst S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report: The bright GRB 090929A (Fermi-GBM trigger trigger 275891585: Rau, GCN 9962) localized by Swift-BAT (Cummings and Krimm, GCN 9966) triggered Konus-Wind at T0=16387.790 s UT (04:33:07.790). As observed by Konus-Wind the burst had a fluence of 1.32(-0.24, +0.23)x10^-5 erg/cm2, and a 16-ms peak flux measured from T0+0.736 s of 2.04(-0.61, +0.60)x10^-5 erg/cm2/s (both in the 20 keV - 3 MeV energy range). The time-integrated spectrum of the burst (from T0 to T0+8.448 s) is well fitted (in the 20 keV - 3 MeV range) by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep), with alpha = -0.47(-0.22, +0.25), and Ep = 574(-100, +151) keV (chi2 = 66.2/65 dof). Fitting by GRB (Band) model yields: the low-energy photon index alpha = -0.36(-0.29, +0.62), the high energy photon index beta = -2.16(-1.41, +0.43), the peak energy Ep = 494(-191, +175) keV (chi2 = 62.1/64 dof). These values are consistent with the Konus-RF results (Golenetskii et al., GCN 9968). All the quoted errors are at the 90% confidence level. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB090929_T16384/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9977 SUBJECT: GRB 090929A: Swift-XRT non-detection DATE: 09/09/30 16:21:47 GMT FROM: Kim Page at U.of Leicester K.L. Page (U. Leicester) reports on behalf of the Swift-XRT team: Swift performed a short Target of Opportunity observation of GRB 090929A about 13 hours after the burst (Rau, GCN Circ. 9962; Cummings & Krimm, GCN Circ. 9966; Golenetskii et al., GCN Circ. 9968). This area of sky was a hot target for the XRT, so only a short observation was performed, with 1.4 ks of data being collected in Photon Counting mode. We do not detect a source within the BAT error circle, to a 90% upper limit of 0.015 count s^-1 over 0.3-10 keV. Assuming a typical counts to flux conversion of 3.8 x 10^-11 erg cm^-2 ct^-1 (Evans et al., 2009, MNRAS, 397, 1177), this corresponds to an observed flux of 5.7 x 10^-13 erg cm^-2 s^-1. We note that this is not a very constraining upper limit, because of the greater than usual background caused by the high XRT CCD temperature and the short exposure time. Filtering out all photons below 1 keV, a more stringent upper limit of 9 x 10^-3 count s^-1 (1-10 keV; observed flux of ~3.4 x 10^-13 erg cm^-2 s^-1) can be determined. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9980 SUBJECT: GRB 090929A, Swift-BAT refined analysis DATE: 09/09/30 21:06:52 GMT FROM: Jay R. Cummings at NASA/GSFC/Swift 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), C. B. Markwardt (GSFC/UMD), K. Page (U Leicester), D. M. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team): We report further analysis of Fermi-GBM GRB 090929A (Rau, et al., GCN Circ. 9962). The BAT ground-calculated position is the same as stated in Cummings et al. (GCN Circ. 9966), RA, Dec = 56.494, -5.952 or RA (J2000) 03h 45m 57.9s Dec (J2000) -05d 57' 50" with an estimated 90% containment error radius of 3 arcmin. The partial coding was 73-90% during the burst. The mask-weighted lightcurve shows multiple peaks and spikes, at T+1, T+2, T+4, T+5, and T+10 sec, where T0 is 04:33:07. T90 was 7 +- 2 seconds. The time-averaged spectrum from T0 to T+12 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 0.96 +- 0.04. The fluence in the 15-150 keV band is 1.69 +- 0.07 x 10^-06 ergs/cm2. The 1-sec peak photon flux measured from T+0.5 sec in the 15-150 keV band is 5.9 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence level. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9981 SUBJECT: GRB 090929A: Swift/UVOT Observations DATE: 09/09/30 22:34:16 GMT FROM: Mike Siegel at PSU/Swift MOC M. H. Siegel (PSU) and K. L. Page (U. Leicester) report on behalf of the Swift/UVOT team. Swift/UVOT began settled observations of GRB 090929A about 13 hours after the burst (Rau, GCN Circ. 9962; Cummings & Krimm, GCN Circ. 9966; Golenetskii et al., GCN Circ. 9968; Page, GCN Circ 9977). Due to the presence of a 9th magnitude (V) star 45" from the center of the BAT position, data were only obtained in the UVM2 filter. We do not detect any uncatalogued UV source within the BAT error circle. The 3-sigma upper limit and summed exposure is reported below: FILTER T_start(s) T_stop Exposure Mag/3UL ============================================================= UVM2 47411 52924 2252 >21.26 ============================================================= This magnitude is not corrected for the Galactic extinction corresponding to a reddening of E_{B-V} = 0.07 (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: 9992 SUBJECT: GRB 090929A: Suzaku WAM observation of the prompt emission DATE: 09/10/05 08:59:49 GMT FROM: Norisuke Ohmori at Miyazaki U N. Ohmori, E. Sonoda, K. Kono, H. Hayashi, A. Daikyuji, Y. Nishioka, K. Noda, M. Yamauchi (Univ. of Miyazaki), M. Ohno, M. Suzuki, M. Kokubun, T. Takahashi (ISAS/JAXA), K. Yamaoka, S. Sugita (Aoyama Gakuin U.), Y. E. Nakagawa, T. Tamagawa (RIKEN), S. Hong (Nihon U.), N. Vasquez (Tokyo Tech.), Y. Hanabata, T. Uehara, T. Takahashi, Y. Fukazawa (Hiroshima U.), W. Iwakiri, M. Tashiro, Y. Terada, A. Endo, K. Onda, T. Sugasahara (Saitama U.), Y. Urata (NCU), T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo), on behalf of the Suzaku WAM team, report: The long GRB 090929A (Fermi-GBM trigger 275891585 / 090929190; Arne Rau et al., GCN9962) triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 04:33:04.634 UT (=T0). The observed light curve shows a bright multi-peaked structure starting at T0-1 s, ending at T0+5 s. The total T90 duration is about 3.8 seconds. The fluence in 100 - 1000 keV was 4.96 (-4.47, +5.32) x10-6 erg/cm2. The 1-s peak flux measured from T0-0.5s was 5.59 (-0.68, +0.53) photons/cm2/s in the same energy range. The incident angle for this burst is not good, so the fluence and peak flux might have large systematic uncertainties. Preliminary result shows that the time-averaged spectrum from T0-1s to T0+5s is well fitted by a power-law with exponential cutoff model: dN/dE ~ E^{-alpha} * exp(-(2-alpha)*E/Epeak) with alpha 0.86(-0.80, +0.36), and Epeak 557(-98, +117) keV (chi2/d.o.f. = 125/98). All the quoted errors are at statistical 90% confidence level, in which the systematic uncertainties are not included. The light curves for this burst is available at: http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10010 SUBJECT: Detection of a short GRB 090929A by RT-2 Experiment DATE: 09/10/11 06:52:39 GMT FROM: Sandip K. Chakrabarti at S.N. Bose Nat. Centre for Basic Sci. S. K. Chakrabarti, A. Nandi, D. Debnath, T. C. Kotoch (ICSP, Kolkata, India), A. R. Rao, J. P. Malkar, M. K. Hingar, V. K. Agrawal (TIFR, Mumbai, India), T. R. Chidambaram, P. Vinod, S. Sreekumar (VSSC, Thiruvananthapuram, India), Y. D. Kotov, A. S. Buslov, V. N. Yurov, V. G. Tyshkevich, A. I. Arkhangelskij, R. A.Zyatkov (MephI, Moscow, Russia) report: The RT-2 Experiment onboard the CORONAS-PHOTON satellite has detected GRB 090929A (Fermi-GBM trigger 275891585/090929190; Rau, GCN 9962) which is triggered at T0 = 04h 33m 04s (UT). The satellite was in the LIGHT mode (pointing towards the SUN) with GOOD time (away from the polar and SAA regions) observation of 1537 sec starting at 04h 21m 20sec (UT) and ending at 04h 46m 57sec (UT). The burst light curve (1 sec bin) shows double peak profile of total duration of around 5 sec. The strongest peak count rate is ~ 310 cts/sec. This burst is also independently detected by KONUS-RF, another instrument onboard CORONAS-PHOTON satellite (Golenetskii et al., 2009, GCN 9968). Both RT-2/S and RT-2/G detectors have registered the prompt emission from the GRB090929A in the energy band of 60 – 1000 with strongest emission in the energy band of 60 – 215 keV. The light curve is available at the web-site: http://csp.res.in/rt2_files/grb090929-lc.html