GCN Circular 26745
Subject
LIGO/Virgo S200114f: No counterpart candidates in Fermi-LAT observations
Date
2020-01-14T11:02:00Z (5 years ago)
From
Lorenzo Scotton at CNRS/IN2P3/LUPM <lorenzoscotton@live.it>
L. Scotton (CNRS/IN2P3/LUPM), M. Crnogorcevic (Univ. of Maryland &
NASA/GSFC), M. Axelsson (KTH & Stockholm Univ.) and F. Longo (University
and INFN, Trieste) report on behalf of the Fermi-LAT Collaboration:
We have searched data collected by the Fermi Large Area Telescope (LAT)
on Jan 14, 2020,��for possible high-energy (E > 100 MeV) gamma-ray
emission in��spatial/temporal��coincidence with the LIGO/Virgo trigger
S200114f (GCN 26734).
We define "instantaneous coverage" as the integral over the region of
the LIGO��probability map that is within the LAT field of view at a given
time, and��"cumulative��coverage" as the integral of the instantaneous
coverage over time.��Fermi-LAT had��an instantaneous coverage of ~87% of
the LIGO probability at the��time of the trigger��(T0 =
2020-01-1402:08:18.230UTC), and reached 100%��cumulative coverage��after
~4.2 ks.
We performed a search for a transient counterpart within the observed
region of the 90% contour of��LIGO map in a fixed time window from T0 to
T0 + 10 ks.��No significant new sources��are found.
We also performed a search which adapted the time interval of the
analysis to the��exposure of each region of the sky, and no additional
excesses were found.
Energy flux upper bounds for the fixed time interval��between 100 MeV and
1 GeV��for this search vary��between 2e-10 and 2e-08 [erg/cm^2/s].
The Fermi-LAT point of contact for this event is Milena Crnogorcevic
(mcrnogor@astro.umd.edu).
The Fermi-LAT is a pair conversion telescope designed to cover��the
energy band��from 20 MeV to greater than 300 GeV.��It is the product of an
international collaboration between��NASA and DOE in the U.S. and many
scientific institutions��across France,��Italy, Japan and Sweden.