[vsnet-grb-info 16073] GRB150127A: Fermi GBM Detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17355
SUBJECT: GRB150127A: Fermi GBM Detection
DATE:    15/01/28 00:46:25 GMT
FROM:    Matthew Stanbro at UAH/Fermi  <mcs0001 at uah.edu>

Matthew Stanbro (UAH) and A. von Kienlin (MPE)
report on behalf of the Fermi GBM Team:

"At 09:32:44.14 UT on 27 January 2015, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 150127A (trigger 444043967 / 150127398).

The on-ground calculated location, using the GBM trigger
data, is RA = 285.7, DEC = -8.4, with an uncertainty
of 2.8 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 39 degrees.

The GBM light curve consists of several episodes
with a duration (T90) of about 53 s (50-300 keV).
The time-averaged spectrum from T0-0.00 s to T0+51.20 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.04 +/- 0.04 and
the cutoff energy, parameterized as Epeak, is 1478 +/- 225 keV.

A Band function fits the spectrum equally well
with Epeak= 1083 +/- 212 keV, alpha = -0.99 +/- 0.05 and beta = -2.21 +/- 0.23.

The event fluence (10-1000 keV) in this time interval is
(2.27 +/- 0.50)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-0.32 s in the 10-1000 keV band
is 7.78 +/- 0.33 ph/s/cm^2.

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