[vsnet-grb-info 9494] GRB 100722A: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  10966
SUBJECT: GRB 100722A: Fermi GBM detection
DATE:    10/07/23 08:12:08 GMT
FROM:    Elisabetta Bissaldi at MPE  <ebs at mpe.mpg.de>

Elisabetta Bissaldi (MPE) 
reports on behalf of the Fermi GBM Team: 


"At 02:18:37.24 UT on 22 July 2010, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 100722A (trigger 301457919 / 100722096).
The on-ground calculated location, using the GBM trigger
data, is RA = 238.8, DEC = -15.6 (J2000 degrees,
equivalent to 15h 55m, -15d 36), with an uncertainty
of 1.1 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).
The Fermi Observatory executed a maneuver following this trigger and
tracked the burst location for the next 5 hours, subject to
Earth-angle constraints.

The angle from the Fermi LAT boresight is 33 degrees.

This burst was also independently detected by INTEGRAL SPI-ACS.

The GBM light curve consists of several peaks
with a duration (T90) of 6.6 +/- 0.2 s (50-300 keV).
The time-averaged spectrum from T0 to T0+6.7 s is
best fit by a Band function with Epeak = 68.1 (-3.5/+3.4) keV,
alpha = -1.01 (-0.06/+0.07), beta = -2.54 (-0.10/+0.08)
(Castor C-STAT 627 for 479 d.o.f.).

The event fluence (8-1000 keV) in this time interval is
(9.5 +/- 0.09) erg/cm^2. The 1-sec peak photon flux measured
starting from T0 in the 8-1000 keV band
is 26.9 +/- 0.4 ph/s/cm^2.


The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."