Gamma-ray Burst 140619B

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN Circular #16419
  V. Connaughton, B-B. Zhang (UAH), G. Fitzpatrick, and O. Roberts (UCD) report on behalf of the Fermi GBM Team:
  "At 11:24:40.52 UT on 19 June 2014, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 140619B (trigger 424869883 / 140619475)
  The on-ground calculated location, using the GBM trigger data, is RA = 133.4, DEC = -3.7 (J2000 degrees, equivalent to 08h 54m, -3d 42'), with an uncertainty of 5 degrees (radius, 1-sigma containment, statistical only; there is additionally a systematic error which is currently estimated to be 2 to 3 degrees).
  The GBM light curve consists of a single peak with substructure, with a duration (T90) of about 0.5 s (50-300 keV). The time-averaged spectrum from T0-0.192 s to T0+0.640 s is well fit by a power law function with an exponential high-energy cutoff. The power law index is -0.11 +/- 0.16 and the cutoff energy, parameterized as Epeak, is 1450 +/- 220 keV
  The event fluence (10-1000 keV) in this time interval is (1.70 +/- 0.09)E-6 erg/cm^2. The 64-msec peak photon flux measured starting from T0+0.38 s in the 10-1000 keV band is 7.6 +/- 3.4 ph/s/cm^2.
  A Band function fits the spectrum equally well with Epeak= 1356 +/- 252 keV, alpha = -0.06 +/- 0.19 and beta = 3.3 +/- 1.4.
  The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
• GCN Circular #16420
  GRB 140619B: Fermi-LAT detection
  D. Kocevski (NASA/GSFC), F. Longo (University and INFN Trieste), G. Vianello (Stanford University), V. Connaughton (University of Alabama, Huntsville), J. McEnery (NASA/GSFC) and E.Sonbas (Adiyaman Univ.) report on behalf of the Fermi-LAT team:
  At UT 11:24:47 on June 19, 2014, Fermi-LAT detected high-energy emission from GRB 140619B, which was also detected by Fermi-GBM (trigger 424869883 / 140619475). A preliminary analysis of GBM data characterizes this event as a short hard burst, with a T90 duration of ~0.5s (GCN 16419).
  The best LAT on-ground location is found to be:
  (RA, Dec) = 132.68, -9.66 (deg, J2000)
  with an approximate error radius of 0.06 deg (90% containment, statistical error only).
  This was 32 deg from the LAT boresight at the time of the trigger. The data from the Fermi-LAT show a significant increase in the event rate within ~3 degree of the GBM location after the GBM trigger that is spatially and temporally correlated with the GBM emission with high significance. More than 19 photons above 100 MeV and more than 5 photons above 1 GeV are observed within 5 seconds. The highest-energy photon is a 24 GeV event which is observed 0.61 seconds after the GBM trigger.
  The Fermi-LAT point of contact for this burst is Eda Sonbas edasonbas@yahoo.com.
  A Swift ToO has been requested for this burst.
  The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.
• GCN Circular #16421
  D. Kocevski (NASA/GSFC), F. Longo (University and INFN Trieste), G. Vianello (Stanford University), V. Connaughton (University of Alabama, Huntsville), J. McEnery (NASA/GSFC) and E.Sonbas (Adiyaman Univ.) report on behalf of the Fermi-LAT team:
  "At UT 11:24:41 on June 19, 2014, Fermi-LAT detected high-energy emission from GRB 140619B, which was also detected by Fermi-GBM (trigger 424869883 / 140619475). A preliminary analysis of GBM data characterizes this event as a short hard burst, with a T90 duration of ~0.5s (Connaughton et al. GCN 16419).
  The best LAT on-ground location is found to be:
  (RA, Dec) = 132.68, -9.66 (deg, J2000)
  with an approximate error radius of 0.06 deg (90% containment, statistical error only).
  This was 32 deg from the LAT boresight at the time of the trigger. The data from the Fermi-LAT show a significant increase in the event rate within ~5 degrees of the GBM location after the GBM trigger time that is spatially and temporally correlated with the GBM emission with high significance. More than 19 photons above 100 MeV and more than 5 photons above 1 GeV are observed within 5 seconds. The highest-energy photon is a 24 GeV event which is observed 0.61 seconds after the GBM trigger.
  The Fermi-LAT point of contact for this burst is Eda Sonbas edasonbas@yahoo.com .
  A Swift ToO has been requested and accepted for this burst.
  The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden."
• GCN Circular #16424
  A. Maselli (INAF-IASFPA) and P. D'Avanzo (INAF-OAB) report on behalf of the Swift-XRT team:
  "We have analysed 3.9 ks of XRT data for the Fermi/GBM and LAT-detected short GRB 140619B (Connaughton et al., GCN Circ. 16419; Kocevski et al., GCN Circ. 16420), from 48.7 ks to 71.6 ks after the GBM trigger. The data are entirely in Photon Counting (PC) mode. No bright X-ray afterglow is detected within the LAT error circle. The three sigma upper limit is 2.9E-03 cts/s.
  This circular is an official product of the Swift-XRT team."
• GCN Circular #16457
  W. Iwakiri(RIKEN), M. Tashiro, Y. Terada, T. Yasuda, S. Koyama, S. Takeda, T. Nagayoshi, J. Enomoto, S. Nakaya, T. Fujinuma, S. Matsuoka (Saitama U.), M. Yamauchi, N. Ohmori, R. Kinoshita (Univ. of Miyazaki), M. Ohno, T. Kawano, S. Furui, Y. Fukazawa(Hiroshima U.), K. Yamaoka (Nagoya U.), S. Sugita (Ehime U.), Y. Hanabata (ICRR), Y. E. Nakagawa, M. Kokubun, T. Takahashi (ISAS/JAXA), Y. Urata (NCU), K. Nakazawa, K. Makishima (Univ. of Tokyo) on behalf of the Suzaku WAM team, report:
  The short GRB 140619B (Fermi-GBM detection : Connaughton et al, GCN 16419; Fermi-LAT detection: Kocevski et al., GCN 16420) triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 11:24:40.128 UT (=T0).
  The observed light curve shows a single peak, lasting from T0 to T0+1 s with a duration (T90) of about 0.7 seconds. The fluence in 100 - 1000 keV was 1.50 (+0.07, -0.22) x10^-6 erg/cm^2. The 1-s peak flux measured from T0 was 2.29 (+0.19, -0.53) photons/cm^2/s in the same energy range.
  Preliminary result shows that the time-averaged spectrum from T0 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 0.45 (+0.31, -0.37), and
  Epeak 1418 (+292, -239) keV (chi^2/d.o.f. = 23.78/29).
  

  All the quoted errors are at statistical 90% confidence level, in which the systematic uncertainties are not included.
  The light curves with 1-sec time resolution for this burst will be appeared at:
  http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/untrig/grb_table.html
• GCN Circular #16466
  W. Fong (Harvard), A. Monson (OCIW), M. Bayliss (Harvard), A. Stark (Harvard), E. Berger (Harvard), B. Stalder (Harvard), and M. Florian (U. Chicago) report:
  "We observed the location of the short-duration GRB 140619B, detected by Fermi/GBM (Connaughton et al., GCN 16419), Fermi/LAT (Kocevski et al., GCN 16420), and Suzaku/WAM (Iwakiri et al., GCN 16457) with the FourStar Infrared Camera mounted on the Magellan/Baade 6.5-m telescope to cover the Fermi/LAT position (90% containment; Kocevski et al., GCN 16420). We obtained 770 sec of J-band observations on 2014 Jun 20.96 UT (1.48 days post-burst). To check for the presence of a fading near-infrared source, we re-observed the field (2300 sec) on 2014 Jun 21.97 UT, 2.49 days post-burst and 1.01 days after the first set of observations.
  Digital image subtraction of the two epochs using the ISIS software package reveals no residuals in or around the Fermi/LAT position. We therefore place a 3-sigma limit of J>22.9 AB mag on the brightness of the near-infrared afterglow of GRB 140619B at 1.48 days after the burst."
• 1412.1018 from 3 Dec 14
  M. Muccino et al.: GRB 140619B: a short GRB from a binary neutron stars merger leading to the black hole formation
  Following the recent identification of the prototypical short GRB 090227B originating from a binary neutron star (NS) merger and forming a black hole (BH), we present here a new example of such sources, GRB 140619B. The time-resolved spectral analysis of the early ~0.2s of the Fermi-GBM data, allows for the identification of the characteristic features of the e^+e^- plasma at transparency (P-GRB): i.e., a thermal spectrum with an observed temperature kT=(324+/-33)keV which represents ~40% of the total source fluence. The subsequent emission, with no thermal spectrum, is identified with the prompt emission. We consequently deduce a theoretical redshift of z=2.67+/-0.37, a total burst energy E+/-=(6.03+/-0.79)x10^{52}erg, a baryon load B=(5.52+/-0.73)x10^{-5}, and a Lorentz factor at transparency Gamma=(1.08+/-0.08)x10^4. From the simulation of the prompt emission we determine the average density of the circumburst medium (CBM), n_CBM=(4.7+/-1.2)x10^{-5}cm^{-3}, typical of the galactic halo environment. These low CBM density and baryon load, confirm the identification of the GRB progenitor as a NS-NS merger. By assuming symmetric NS masses (M_NS=1.34Msun), the inferred baryon load corresponds to ~3% of the total crustal mass, i.e. M_2c=7.26x10^{-5}Msun. The corresponding emission of gravitational waves, in the inspiral phase up to the merger, corresponds to 7.42x10^{52}erg. We also show that the gravitational waves signal from this NS binary progenitor, in view of the large cosmological distance, is undetectable by the Advanced LIGO. Novel is the presence of an observed emission at energies >0.1 GeV lasting ~5s, with a total energy of E_LAT=(2.02+/-0.52)x10^{53}erg. We estimate the energy requirements of E_LAT in terms of accretion of a fraction of M_2c on the BH. From GRBs 090227B and 140619B, we estimate the rate of such short GRBs to be 1.7(+3.7)(-1.4)x10^{-4}/(Gpc^3yr).