GCN Circular 39342
Subject
GRB 250215A: Fermi GBM Observation
Date
2025-02-16T07:17:46Z (2 months ago)
From
Lorenzo Scotton at UAH <lscottongcn@outlook.com>
Via
Web form
L. Scotton (UAH) and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:
"At 02:31:54.94 UT on 15 February 2025, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 250215A (trigger 761279519/250215105), which was also
detected by EP-WXT and FXT (Wang et al., GCN 39329),
INTEGRAL SPI-ACS (Barria et al., GCN 39331), AstroSat CZTI (Tembhurnikar et al., GCN 39334),
SVOM/GRM (Zheng et al., GCN 39335) and Swift-XRT (Page et al., GCN 39336).
NOT (Liu et al., GCN 39330, Malesani et al., GCN 39341), SVOM/VT (Xie et al., GCN 39333)
and Gemini-South (Malesani et al., GCN 39339) detected the optical counterpart.
The Fermi GBM on-ground location is consistent with the Swift-XRT position.
The angle from the Fermi LAT boresight is 28 degrees.
The GBM light curve consists of multiple emission episodes with a duration (T90)
of about 13.4 s (50-300 keV). The time-averaged spectrum
from T0-0.8 to T0+14.5 s is best fit by a Band function
with Epeak = 117 +/- 9 keV, alpha = -0.68 +/- 0.09 and beta = -2.38 +/- 0.14.
The event fluence (10-1000 keV) in this time interval is
(6.2 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+12 s in the 10-1000 keV band is 11.1 +/- 0.3 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html
For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"