GCN Circular 11591
Subject
GRB 110120A: Fermi GBM detection
Date
2011-01-21T16:23:22Z (14 years ago)
From
Lin Lin at UAH/NAOC <ll0005@uah.edu>
Lin Lin (UAH)
reports on behalf of the Fermi GBM Team:
"At 15:59:39.23 UT on 20 January 2011, the Fermi Gamma-Ray Burst
Monitor triggered and located GRB 110120A (trigger 317231981 /
110120666).
The on-ground calculated location, using the GBM trigger
data, is RA = 64.54, DEC = -17.06 (J2000 degrees,
equivalent to 04 h 18 m 09.6 s, -17 d 03 ' 36.0 "), with an
uncertainty of 1.08 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 15 degrees.
This burst triggered the Fermi spacecraft slew because of high
peak flux.
The GBM light curve shows a ~5 s peak followed by a ~40 s
tail with a duration (T90) of about 27 s (50-300 keV).
The time-averaged spectrum from T0+0.003 s to T0+43.393 s is
acceptably fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.87 +/- 0.04 and
the cutoff energy, parameterized as Epeak, is 1156 +/- 172 keV
(C-Stat 666.26 for 487 d.o.f.).
The event fluence (10-1000 keV) in this time interval is
(2.55 +/- 0.05)E-5 erg/cm^2. The 64 ms peak photon flux measured
starting from T0+0.384 s in the 10-1000 keV band
is 15.03 +/- 1.35 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."