Skip to main content
Introducing Einstein Probe, Astro Flavored Markdown, and Notices Schema v4.0.0. See news and announcements

GCN Circular 15688

GRB 140105A: Fermi GBM detection
2014-01-05T21:39:05Z (10 years ago)
Shaolin Xiong at UAH <>
Shaolin Xiong (UAH) and Valerie Connaughton (UAH)
report on behalf of the Fermi GBM Team:

"At 01:33:01.01 UT on 05 January 2014, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 140105A (trigger 410578384 / 140105065).

The on-ground calculated location, using the GBM trigger
data, is RA = 208.22, DEC = 50.17 (J2000 degrees,
equivalent to 13 h 53 m, 50 d 10 '), with an uncertainty
of 6 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 72 degrees.

The optical afterglow candidates reported by iPTF (Singer et al.
GCN 15686) lie within the 1-sigma (statistical and systematic)
uncertainty region surrounding the GBM localization.

The GBM light curve consists of weak pulses
with a duration (T90) of about 0.8 s (50-300 keV).
The time-averaged spectrum from T0-0.064 s to T0+0.64 s is
well fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.98 +/- 0.11 and
the cutoff energy, parameterized as Epeak, is 1200 +/- 500 keV.

The event fluence (10-1000 keV) in this time interval is
(8.7 +/- 0.6)E-7 erg/cm^2. The 64 ms peak photon flux measured
starting from T0 in the 10-1000 keV band is 8.2 +/- 1.2 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
Looking for U.S. government information and services? Visit