GCN Circular 17481
Subject
GRB 150219A: Fermi GBM observation
Date
2015-02-20T10:02:13Z (10 years ago)
From
Andreas von Kienlin at MPE <azk@mpe.mpg.de>
A. von Kienlin (MPE) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:
"At 12:31:12.26 UT on 19 February 2015, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 150219A (trigger 446041875 / 150219522), which
was also detected by INTEGRAL/IBIS (Mereghetti et al. 2015, GCN 17476).
The GBM on-ground location is consistent with the INTEGRAL position.
The angle from the Fermi LAT boresight is 105 degrees.
The GBM light curve shows a structured pulse
with a duration (T90) of about 36 s (50-300 keV).
The time-averaged spectrum from T0-2.304 s to T0+38.657 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.92 (+0.08/-0.07) and
the cutoff energy, parameterized as Epeak, is 202.7(+23.2/-19.1) keV.
The event fluence (10-1000 keV) in this time interval is
(1.00 +/- 0.05)E-05 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+9.664 s in the 10-1000 keV band
is 4.2 +/- 0.3 ph/s/cm^2.
A Band function fits the spectrum equally well with Epeak=
166.7(+24.3/-17.3) keV,
alpha = -0.82 +/- 0.10 and beta = -2.17 (+0.13/-0.24).
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."