GCN Circular 9691
Subject
GRB 090719: Fermi GBM detection
Date
2009-07-20T14:53:16Z (16 years ago)
From
Alexander van der Horst at NASA/MSFC <Alexander.J.VanDerHorst@nasa.gov>
A.J. van der Horst (NASA/MSFC/ORAU) reports on behalf of the Fermi GBM
Team:
"At 01:31:26.61 UT on 19 July 2009, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 090719 (trigger 269659888 / 090719063).
The on-ground calculated location, using the GBM trigger data, is
RA = 341.3, DEC = -67.9 (J2000 degrees, equivalent to 22h45m, -67d52'),
with an statistical uncertainty of less than 1 degree (radius, 1-sigma
containment), and an additional systematic error which is currently
estimated to be 2 to 3 degrees.
The angle from the Fermi LAT boresight is 88 degrees.
The GBM light curve consists of a bright pulse with some substructure,
with a duration (T90) of about 16 s (8-1000 keV).
The time-averaged spectrum from T0 to T0+16.6 s is best fit by
a Band function with Epeak = 254 +/- 6 keV, alpha = -0.68 +/- 0.02,
and beta = -2.92 +/- 0.16 (chi squared 652 for 483 d.o.f.).
The event fluence (8-1000 keV) in this time interval is
(4.83 +/- 0.04)E-5 erg/cm^2. The 1-sec peak photon flux
measured starting from T0+4.4 s in the 8-1000 keV band
is 37.8 +/- 0.5 ph/s/cm^2.
The temporal and spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."