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GCN Circular 36481

Subject
GRB 240514B: Fermi GBM Detection
Date
2024-05-14T22:49:03Z (4 days ago)
From
Oliver J Roberts at USRA/NASA <oliver.roberts@nasa.gov>
Via
Web form
O.J. Roberts (USRA-NASA/MSFC) and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:

"At 04:03:45.04 UT on 14 May 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 240514B (trigger 737352230/240514169).

The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 5.1, Dec = 44.5 (J2000 degrees, equivalent to J2000 22h 47m, -1d 19'), 
with a statistical uncertainty of 4.0 degrees. There is additionally a 
systematic error which we have characterized  as a core-plus-tail model, 
with 90% of GRBs having a 3.7 deg error and a small tail suffering a 
larger than 10 deg systematic error (Connaughton et al. 2015, ApJS, 216, 32).

This is an improved localization that replaces the Final Position notice
GCN sent out earlier (Fermi GBM Team, 2021, GCN 36469). 

The angle from the Fermi LAT boresight is 111 degrees.

The GBM light curve shows two bright peaks with a duration (T90)
of about 1.7 s (50-300 keV). The time-averaged spectrum
from T0-0.06 to T0+0.70 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -0.75 +/- 0.07 and the cutoff energy,
parameterized as Epeak, is 957 +/- 130 keV.

The event fluence (10-1000 keV) in this time interval is
(2.7 +/- 0.1)E-06 erg/cm^2. The 64-ms peak photon flux measured
starting from T0+0.32 s in the 10-1000 keV band is 16 +/- 2 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/"
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