//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20835 SUBJECT: GRB 170307A: Fermi GBM observation DATE: 17/03/08 05:44:32 GMT FROM: C. Michelle Hui at MSFC/Fermi-GBM C.M. Hui (NASA/MSFC) and O.J. Roberts (USRA/NASA) report on behalf of the Fermi GBM Team: At 20:25:17.49 UT on 07 March 2017, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 170307A (trigger 510611122 /170307851), which was also detected by Swift BAT (A. Y. Lien et al., GCN 20832). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight at the GBM trigger time using the Swift-BAT location is 98 degrees. The GBM light curve consists of multiple peaks with a duration (T90) of about 57.9s (50-300 keV). The time-averaged spectrum from T0-27.6s to T0+28.7 s is adequately fit by a power law function with an exponential high-energy cutoff. The power law index is -1.18 +/- 0.26 and the cutoff energy, parameterized as Epeak, is 83.80 +/- 19.90 keV. The event fluence (10-1000 keV) in this time interval is (1.85 +/- 0.25)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+8.3 s in the 10-1000 keV band is 1.72 +/- 0.25 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: 20838 SUBJECT: GRB 170307A (trigger 741528): Swift-BAT refined analysis DATE: 17/03/08 13:59:24 GMT FROM: Amy Lien at GSFC M. Stamatikos (OSU), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), N. Gehrels (GSFC), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-12 to T+963 sec from the recent telemetry downlink, we determine that BAT trigger #741528 (Lien et al., GCN Circ. 20832) is indeed a GRB, which also detected by Fermi GBM (Hui et al., GCN Circ. 20835). We report further analysis of BAT GRB 170307A (trigger #741528). The BAT ground-calculated position is RA, Dec = 13.510, 9.538 deg which is RA(J2000) = 00h 54m 02.5s Dec(J2000) = +09d 32' 17.9" with an uncertainty of 2.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 43%. The mask-weighted light curve shows a weak structure with several overlapping pulses that starts at ~T+55 s and ends at ~T+125 s. The burst emission might start before it came into the BAT FOV at ~T-12 s. T90 (15-350 keV) is 56.92 +- 27.40 sec (estimated error including systematics). The time-averaged spectrum from T+55.33 to T+124.69 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.88 +- 0.23. The fluence in the 15-150 keV band is 1.3 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+69.72 sec in the 15-150 keV band is 1.4 +- 0.3 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/741528/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20880 SUBJECT: GRB 170307A: 15 GHz upper limit from AMI DATE: 17/03/16 15:14:11 GMT FROM: Kunal Mooley at Oxford U K. P. Mooley, T. D. Staley, R. P. Fender (Oxford), G. E. Anderson (Curtin), T. Cantwell (Manchester), D. Titterington, S. H. Carey, J. Hickish, Y. C. Perrott, N. Razavi-Ghods, P. Scott (Cambridge), K. Grainge, A. Scaife (Manchester) We observed the GRB 170307A detected by Swift (Lien et al., GCN 20832, Stamatikos et al. GCN 20838) and Fermi (Hui et al. GCN 20835) with the AMI Large Array at 15 GHz on 2016 Mar 13.57 (UT). We place a 3sigma upper limit of 90 uJy on the radio afterglow. We thank the AMI staff for scheduling this observation. The AMI-GRB database is a log of all GRB follow up observations with the AMI, and is available at http://4pisky.org/ami-grb/.