[vsnet-grb-info 16436] GRB 150416A: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17717
SUBJECT: GRB 150416A: Fermi GBM detection
DATE:    15/04/17 18:32:07 GMT
FROM:    Peter Jenke at MSFC  <peter.a.jenke at nasa.gov>

P. Jenke (UAH) reports on behalf of the Fermi GBM Team:

"At 18:33:25.97 on April 16 2015, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 150416A (trigger 450902008/150416773) which
was also detected by Fermi-LAT (D. Kocevski et al., GCN 17711)
The GBM on-ground location, using the Fermi GBM trigger
data, is RA = 58.8, Dec = 53.0 (J2000 degrees, equivalent to 
3h 55m 00s, 53d 0’), with an uncertainty of 1.9 
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 of the burst direction to the Fermi LAT boresight is 
68 degrees.

The GBM light curve consists of two peaks with a duration
(T90) of about 33 s (50-300 keV).
The time-averaged spectrum from T0+0s to T0+34.8s 
is well fit by a BAND function with Epeak = 940 +/- 160 keV, 
Alpha = -0.9 +/- 0.05 and Beta = -2.1 +/- 0.2. 
The event fluence (10-1000 keV) in this time interval is
(1.4 +/- 0.04)E-05 erg/cm^2. The 1.0-sec peak photon flux measured
starting from T0+12.8 s in the 10-1000 keV band
is 3.8 +/- 0.2 ph/s/cm^2.


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