//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9666 SUBJECT: GRB 090715: Swift detection of a short hard burst DATE: 09/07/15 17:44:43 GMT FROM: David Palmer at LANL J. L. Racusin (PSU), W. H. Baumgartner (GSFC/UMBC), N. Gehrels (NASA/GSFC), C. Gronwall (PSU), D. Grupe (PSU), S. T. Holland (CRESST/USRA/GSFC), R. Margutti (Univ Bicocca&OAB), K. L. Page (U Leicester), D. M. Palmer (LANL), P. Romano (INAF-IASFPA), M. H. Siegel (PSU), M. Stamatikos (NASA/ORAU) and L. Vetere (PSU) report on behalf of the Swift Team: At 17:25:39 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 090715 (trigger=357498). The BAT on-board calculated location is RA, Dec 152.122, +9.997 which is RA(J2000) = 10h 08m 29s Dec(J2000) = +09d 59' 51" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single-peaked structure with a duration of about 0.4 sec. The peak count rate was ~11,000 counts/sec (15-350 keV), at ~0.3 sec after the trigger. Due to current problems with the Solid State Recorder (GCN 9664), automatic slewing to sources is disabled. However, this burst location is also in Sun constraint and will not come out of constraint until October 9, 2009. There will thus be no XRT or UVOT data for this trigger. We note the existence of an S0/A galaxy NGC 3130 (z=0.027) near the edge of the BAT error circle (nominal position of the galaxy is 4.33 arcminutes from the center of the error circle, with NED reporting a radius of 1.0 arcmin for the galaxy). Burst Advocate for this burst is J. L. Racusin (racusin AT astro.psu.edu). 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: 9667 SUBJECT: GRB 090715A: ROTSE-III Optical Limits DATE: 09/07/15 17:47:35 GMT FROM: Shashi Bhushan Pandey at ARIES, INDIA S. B. Pandey (U Mich), S.A. Yost (College of St. Benedict), W. Zheng, F. Yuan (U Mich), report on behalf of the ROTSE collaboration: ROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia, responded to the short-hard GRB 090715A (Swift trigger 357498, Racusin J. L., GCN 9666), producing images beginning 7.1 s after the GCN notice time. An automated response took the first image at 17:26:05.1 UT, 25.9 s after the burst, under fair conditions. We took 10 5-sec and 10 20-sec exposures and imaging is ongoing. These unfiltered images are calibrated relative to USNO A2.0 (R). Comparison to the DSS (second epoch) reveals no new sources within the 3-sigma Swift/BAT error circle, for both single images and coadding into sets of 10. Individual images have limiting magnitudes ranging from 15.4-16.6; we set the following specific limits. start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd? -------------------------------------------------------------------- 17:26:05.1 17:27:21.5 76 16.8 25.9 Y 17:27:36.4 17:32:18.5 282 17.4 117.2 Y //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9680 SUBJECT: GRB 090715A: Swift-BAT refined analysis DATE: 09/07/16 13:24:23 GMT FROM: Scott Barthelmy at NASA/GSFC W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), 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), A. M. Parsons (GSFC), J. L. Racusin (PSU), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), 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+963 sec from recent telemetry downlinks, we report further analysis of BAT GRB 090715A (trigger #357498) (Racusin, et al., GCN Circ. 9666). The BAT ground-calculated position is RA, Dec = 152.102, 10.006 deg, which is RA(J2000) = 10h 08m 24.5s Dec(J2000) = +10d 00' 22.4" with an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 22%. The mask-weighted light curve shows a single spike starting at ~T-0.1 sec, peaking at ~T+0.1 sec, and ending at ~T+0.7 sec. Following the intial spike, there is extended emission from ~T+20 to ~T+55 sec at a flux level ~50 times lower than the peak flux of the spike. T90 (15-350 keV) is 63 +- 18 sec (estimated error including systematics). The time-averaged spectrum from T-0.1 to T+67.8 sec is best fit by a simple power-law model. We note that this spectral analysis includes both the spike and the extended emission. Qualitatively, the spike is harder than the extended emission. The power law index of the time-averaged spectrum is 1.28 +- 0.42. The fluence in the 15-150 keV band is 9.8 +- 2.2 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-0.11 sec in the 15-150 keV band is 3.9 +- 0.5 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/357498/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9682 SUBJECT: Konus-Wind observations of short/hard GRB 090715A DATE: 09/07/16 17:34:07 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 short hard GRB 090715A (Swift trigger=357498: Racusin et al., GCN 9666; Baumgartner et al., 9680) triggered Konus-Wind at T0=62736.657 s UT (17:25:36.657). The burst had a duration of ~0.32 s. The Konus-Wind light curves of this GRB are available at http://www.ioffe.ru/LEA/GRBs/GRB090715_T62736/ As observed by Konus-Wind the burst had a fluence of 3.5(-1.5,+2.1)x10-6 erg/cm2, and a 16-ms peak flux measured from T0+0.016 s of 2.0(-0.8,+1.2)x10-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum of the burst (from T0 to T0+0.128 s) is well fitted (in the 20 keV - 10 MeV range) by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -1.13(-0.25,+0.42), and Ep = 1658(-1010,+3957)keV (chi2 = 8.9/13 dof). Fitting by GRB (Band) model yields: the low-energy photon index alpha = -0.90(-0.45,+1.2), the high energy photon index beta < -1.5, the peak energy Ep = 738(-614,+3775) keV (chi2 = 8.2/12 dof). The emission is clearly seen up to 7 MeV. All the quoted values are preliminary. All the quoted errors are at the 90% confidence level. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9683 SUBJECT: GRB 090715A: VLA observations DATE: 09/07/17 03:04:11 GMT FROM: Edo Berger at Harvard E. Berger and W.-f. Fong (Harvard) report: "We observed the field centered on the BAT error circle of the short GRB 090715A (GCNs #9666,9680) with the VLA at a frequency of 8.46 GHz starting on 2009 July 16.98 UT (30.1 hours post burst). We detect a single bright source within the BAT error circle which is cataloged in the VLA FIRST survey and is moreover extended. No other sources are detected within the BAT error circle above a 4-sigma level of 85 microJy. In addition, we do not detect any point source in coincidence with the nearby galaxy NGC3130." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9686 SUBJECT: GRB 090715A: Suzaku WAM observation of the prompt emission DATE: 09/07/18 10:53:24 GMT FROM: Kazutaka Yamaoka at Aoyama Gakuin U S. Sugita, K. Yamaoka (Aoyama Gakuin U.), M. Ohno, M. Suzuki, M. Kokubun, T. Takahashi (ISAS/JAXA), M. Tashiro, Y. Terada, A. Endo, K. Onda, W. Iwakiri, T. Sugasahara (Saitama U.), Y. E. Nakagawa, T. Tamagawa (RIKEN), N. Ohmori, A. Daikyuji, E. Sonoda, K. Kono, H. Hayashi, K. Noda, Y. Nishioka, M. Yamauchi (Univ. of Miyazaki), N. Vasquez (Tokyo Tech.), Y. Urata (NCU), Y. Hanabata, T. Uehara, T. Takahashi, Y. Fukazawa (Hiroshima U.), T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo), S. Hong (Nihon U.), on behalf of the Suzaku WAM team, report: The short hard GRB 090715A (Swift/BAT trigger #357498; Racusin et al., GCN 9666; Baumgartner et al., GCN 9680) triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 2009-07-15 17:25:39.033 UT (=T0). The observed light curve shows a multi-peaked structure, starting at T0+0.05 s and ending at T0+0.70 s, with a total duration (T90) of about 0.5 s. The fluence in 100 - 1000 keV was 1.13(-0.20, +0.08) x10^-6 erg/cm^2. The 1-s peak flux measured from T0 s was 2.25(-0.29, +0.12) photons/cm^2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0 s to T0+1 s is well fitted by a power-law with exponential cutoff model: dN/dE ~ E^{-alpha} * exp(-(2-alpha)*E/Epeak) with alpha: 0.76(-0.46, +0.37), and Epeak: 588(-118, +216) keV (chi^2/d.o.f. = 18.1/30). All the quoted errors are at statistical 90% confidence level, in which the systematic uncertainties are not included. The light curves for this burst will be available at: http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html