[vsnet-grb-info 9442] GRB 100701B: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  10920
SUBJECT: GRB 100701B: Fermi GBM detection
DATE:    10/07/02 08:50:29 GMT
FROM:    Suzanne Foley at MPE  <sfoley at mpe.mpg.de>

S. Foley (MPE)
reports on behalf of the Fermi GBM Team:

"At 11:45:23.07 UT on 01 July 2010, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 100701B (trigger 299677525 / 100701490).

The on-ground calculated location, using the GBM trigger
data, is RA = 45.49, DEC = -3.43 (J2000 degrees,
equivalent to 03 h 02 m, -03 d 26 '), with an uncertainty
of 1.0 degree (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 107 degrees.

The GBM light curve consists of at least six main pulses
with a duration (T90) of about 27.5 (+/-0.9) s (8-1000 keV).
The time-averaged spectrum from T0-1.2 s to T0+32.7 s is
well fit by a power law function with an exponential
high energy cutoff.  The power law index is -0.99 (+/-0.02) and
the cutoff energy, parameterized as Epeak, is 1.85 (+/-0.16) MeV
(CSTAT 695.8 for 360 d.o.f.).

The event fluence (8-1000 keV) in this time interval is
(2.86 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+3.4 s in the 8-1000 keV band
is 22.6 +/- 0.3 ph/s/cm^2.

A Band function fits the spectrum equally well (CSTAT 689.8 for 359 d.o.f.)
with Epeak= 1.48 (+0.19/-0.17) MeV, alpha = -0.95 (+/-0.03) and beta =
-2.47 (+0.18/-0.25) .


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