Gamma-ray Burst 150330A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN Circular #17658
  Matthew Stanbro (UAH) reports on behalf of the Fermi GBM Team:
  "At 19:52:21.27 UT on 30 March 2015, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 150330A (trigger 449437944 / 150330828). The trigger resulted in an Autonomous Repoint Request (ARR) that was accepted and the spacecraft slewed to the GBM in-flight location.
  The on-ground calculated location, using the GBM trigger data, is RA = 329.26, DEC = 49.97, with an uncertainty of 1.00 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 80 degrees.
  The GBM light curve shows/consists of two main episodes with a combined duration (T90) of about 153 s (50-300 keV). The time-averaged spectrum from T0+0.00 s to T0+151.68 s is best fit by a Band function with Epeak = 284 +/- 5 keV, alpha = -0.91 +/- 0.01, and beta = -2.15 +/- 0.02
  The event fluence (10-1000 keV) in this time interval is (1.28 +/- 0.01)E-04 erg/cm^2. The 1-sec peak photon flux measured starting from T0+130.8 s in the 10-1000 keV band is 59.26 +/- 0.51 ph/s/cm^2.
  The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
• GCN Circular #17659
  K. Hurley and J. Goldsten, on behalf of the MESSENGER NS GRB team,
  S. Golenetskii, R. Aptekar, V. Pal'shin, D. Frederiks, D. Svinkin, and T. Cline on behalf of the Konus-Wind team,
  V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa, and A. Goldstein, on behalf of the Fermi GBM team,
  S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer, on behalf of the Swift-BAT team,
  A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and
  G. Di Cocco, F. Fuschino, M. Galli, C. Labanti, and M. Marisaldi, on behalf of the AGILE MCAL team, report:
  The long-duration, very intense GRB 150330A has been detected by Fermi (GBM: Stanbro, GCN Circ 17658), Konus-Wind, MESSENGER (GRNS), INTEGRAL (SPI-ACS), Swift (BAT) and AGILE (MCAL), so far, at about 71541 s UT (19:52:21). The burst was outside the coded field of view of the BAT.
  We have triangulated it to a preliminary, 3 sigma error box whose coordinates are:

  ---------------------------------------------
     RA(2000), deg                 Dec(2000), deg
    ---------------------------------------------
    Center:
     331.028 (22h 04m 07s) +52.297 (+52d 17' 48")
    Corners:
     327.825 (21h 51m 18s) +50.740 (+50d 44' 25")
     328.325 (21h 53m 18s) +51.170 (+51d 10' 12")
     334.589 (22h 18m 21s) +53.730 (+53d 43' 47")
     333.942 (22h 15m 46s) +53.336 (+53d 20' 10")
    ---------------------------------------------
  

  The error box area is 2388 sq. arcmin, and its maximum dimension is 5.1 deg (the minimum one is 8.6 arcmin). The Sun distance was 57 deg.
  This box may be improved.
  A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB150330_T71538/IPN/
  The Konus-Wind time history and spectrum will be given in a forthcoming GCN Circular.
• GCN Circular #17660
  S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko, and T. Cline on behalf of the Konus-Wind team, report:
  The long-duration, very bright GRB 150330A (Fermi-GBM detection: Stanbro, GCN 17568 IPN triangulation: Hurley et al., GCN 17659) triggered Konus-Wind at T0=71538.572 s UT (19:52:18.572).
  The light curve starts with a double-peaked pulse lasting from ~T0 to ~T0+10 s followed by a bright multi-peaked structure from ~T0+97 s to ~T0+195 s. The emission is seen up to ~15 MeV.
  As observed by Konus-Wind, the burst had a fluence of 2.1(-0.2,+0.2)x10^-4 erg/cm2, and a 64-ms peak flux, measured from T0+130.560 s, of 3.4(-0.1,+0.1)x10^-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range).
  The time-averaged spectrum (measured from T0 to T0+194.560 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.96 (-0.07,+0.07), the high energy photon index beta = -2.16 (-0.11,+0.08), the peak energy Ep = 222 (-20,+21) keV, chi2 = 85/97 dof.
  The spectrum near the peak count rate (measured from T0+129.536 to T0+131.072 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.72 (-0.09,+0.09), the high energy photon index beta = -1.98 (-0.08,+0.06), the peak energy Ep = 341 (-44,+52) keV, chi2 = 107/96 dof.
  The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB150330_T71538/
  All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.