GCN Circular 13429
Subject
GRB 120709A: Fermi GBM detection
Date
2012-07-10T23:19:36Z (12 years ago)
From
Sylvain Guiriec at UAH <sylvain.guiriec@lpta.in2p3.fr>
Sylvain Guiriec (GSFC), Valerie Connaughton (UAH)
and Michael Briggs (UAH)
report on behalf of the Fermi GBM Team:
"At 21:11:40.37 UT on 09 July 2012, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 120709A (trigger 120709883 / 120709.883).
The on-ground calculated location, using the GBM trigger
data, is RA = 320.02, DEC = -47.87 (J2000 degrees,
equivalent to 21h20m04, -47d52'12), with an uncertainty
of 1.70 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 22 degrees.
The burst was also seen by the LAT (Kocevski et al., GCN 13423)
The GBM light curve consists of 3 intense peaks
with a duration (T90) of about 30 s (50-300 keV).
The time-averaged spectrum from T0 s to T0+41s is
adequately fit by a power law function with an exponential
high-energy cutoff. The power law index is -1.22 +/- 0.03 and
the cutoff energy, parameterized as Epeak, is 449 +/- 55 keV
The event fluence (10-1000 keV) in this time interval is
(1.43 +/- 0.04)E-5 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+11.65 s in the 10-1000 keV band
is 11.4897 +/- 0.2869 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."