Gamma-ray Burst 140306A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN Circular #15935
  G. Fitzpatrick (UCD) and M. Stanbro (UAH) report on behalf of the Fermi GBM Team:
  At 03:29:44.95 UT on 06 March 2014, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 140306A (trigger 415769387/140306146). 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 = 31.3 , DEC = +45.9 (J2000 degrees, equivalent to 02h 05m, +45d 54.0'), 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 initial angle from the Fermi LAT boresight was 61 degrees.
  The GBM light curve consists of several peak with a duration (T90) of about 68 s (50-300 keV). The time-averaged spectrum from T0-1.21601 s to T0+69.6s is adequately fit by a power law function with an exponential high-energy cutoff. The power law index is -1.10 +/- 0.01 and the cutoff energy, parameterized as Epeak, is 1580 +/- 100 keV
  The event fluence (10-1000 keV) in this time interval is (6.9 +/- 0.06)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+6.5 s in the 10-1000 keV band is 11.7 +/- 0.3 ph/s/cm^2.
  The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog.
• GCN Circular #15938
  S. Golenetskii, R. Aptekar, V. Pal'shin, D. Frederiks, D. Svinkin, and T. Cline, on behalf of the Konus-Wind team,
  K. Hurley and J. Goldsten, on behalf of the MESSENGER NS GRB team,
  I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin, on behalf of the HEND-Odyssey GRB team,
  W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr, on behalf of the GRS-Odyssey GRB team,
  A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,
  K. Yamaoka, M. Ohno, Y. Hanabata, Y. Fukazawa, T. Takahashi, M. Tashiro, Y. Terada, T. Murakami, and K. Makishima, on behalf of the Suzaku WAM team, and
  S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer, on behalf of the Swift-BAT team, report:
  The long-duration, intense GRB 140306A (Fitzpatrick and Stanbro, GCN Circ. 15935) was observed by Fermi (GBM), INTEGRAL (SPI-ACS), Konus-Wind, MESSENGER (GRNS), Suzaku (WAM), Swift (BAT), and Mars Odyssey (HEND) at about 12585 s UT (03:29:45). 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:
      27.943 (01h 51m 46s) +48.975 (+48d 58' 31")
    Corners:
      28.544 (01h 54m 11s) +48.781 (+48d 46' 52")
      28.271 (01h 53m 05s) +49.135 (+49d 08' 06")
      27.339 (01h 49m 21s) +49.163 (+49d 09' 47")
      27.617 (01h 50m 28s) +48.814 (+48d 48' 50")
    ---------------------------------------------
  

  The error box area is 0.209 sq. deg, and its maximum dimension is 53 arcmin (the minimum one is 20 arcmin).
  This box may be improved.
  A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB140306_T12581/IPN/
• GCN Circular #15939
  S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova and T. Cline on behalf of the Konus-Wind team, report:
  The long-duration GRB 140306A (localized by IPN: Golenetskii et al., GCN 15938; GBM detection: Fitzpatrick, GCN 15935) triggered Konus-Wind at T0=12581.686 s UT (03:29:41.686).
  The burst light curve shows an bright multi-peaked pulse with a duration of ~75 s. The emission is seen up to ~8 MeV.
  As observed by Konus-Wind, the burst had a fluence of (1.35 +/- 0.12)x10^-4 erg/cm2, and a 256-ms peak flux, measured from T0+4.592 s, of (2.3 +/- 0.2)x10^-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range).
  The time-integrated spectrum (measured from T0 to T0+78.848 s) is best fit (in the 20 keV - 15 MeV range) by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -1.21 (-0.04, 0.05) and Ep = 1305 (-210,+273) keV (chi2 = 106/98 dof). Fit with the GRB (Band) model yields the same alpha and Ep, and only an upper limit on the high energy photon index: beta < -2.37 (chi2 = 106/97 dof).
  The spectrum near the maximum count rate (measured from T0 to T0+6.656 s) is best fit (in the 20 keV - 15 MeV range) by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -0.77 (-0.05, 0.05) and Ep = 1524 (-142,+158) keV (chi2 = 76/98 dof). Fit with the GRB (Band) model yields the same alpha and Ep, and only an upper limit on the high energy photon index: beta < -2.74 (chi2 = 76/97 dof).
  The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB140306_T12581/
  All the quoted errors are at the 90% confidence level. All the quoted results are preliminary.
• GCN Circular #15940
  T. Yasuda, M. Tashiro, Y. Terada, Y. Ishida, H. Ueno, S. Sugimoto, S. Koyama, S. Takeda, T. Nagayoshi (Saitama U.), M. Yamauchi, N. Ohmori, M. Akiyama, R. Kinoshita (Univ. of Miyazaki), M. Ohno, K. Takaki, T. Kawano, R. Nakamura, S. Furui, Y. Fukazawa (Hiroshima U.), K. Yamaoka (Nagoya U.), S. Sugita (Ehime U.), Y. E. Nakagawa, M. Kokubun, T. Takahashi (ISAS/JAXA), W. Iwakiri (RIKEN), Y. Hanabata (ICRR), Y. Urata (NCU), K. Nakazawa, K. Makishima (Univ. of Tokyo) on behalf of the Suzaku WAM team, report:
  The bright long-duration GRB 140306A (localized by IPN: Golenetskii et al., GCN 15938; and by Fermi-GBM: Fitzpatrick and Stanbro, GCN 15935; and Konus-Wind detection: Golenetskii et al., GCN 15939) triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 03:29:44.404 UT (=T0).
  The observed light curve shows a multi-peaked structure starting at T0 and followed by a long weak tail seen up to T0+60 s with a duration (T90) of about 54 seconds. The fluence in 100 - 1000 keV was 5.38 (+0.09 / -0.13) x10^-5 erg/cm^2. The 1-s peak flux measured from T0+4.5 s was 6.86 (+0.25 / -0.36) photons/cm^2/s in the same energy range.
  Preliminary result shows that the time-averaged spectrum from T0-5 s to T0+60 s is well fitted by a power-law with exponential cutoff model:

  dN/dE ~  E^{-alpha} * exp(-(2-alpha)*E/Epeak) with
  alpha       0.91 (+0.05 / -0.05), and
  Epeak      1426 (+87 / -81) keV (chi^2/d.o.f. = 63.5/51).
  

  All the quoted errors are at statistical 90% confidence level, in which the systematic uncertainties are not included.
  The light curves for this burst are available at:
  http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html