TITLE:   GCN CIRCULAR
NUMBER:  29464
SUBJECT: IceCube-210210A: Upper limits from Fermi-GBM Observations
DATE:    21/02/10 18:34:54 GMT
FROM:    Christian Malacaria at NASA-MSFC/USRA  <cmalacaria@usra.edu>

C. Malacaria (NASA-MSFC/USRA) reports on behalf of the Fermi-GBM Team:

For the IceCube high-energy neutrino candidate event 210210A (GCN 29454),
at the event time Fermi-GBM was observing the reported neutrino location at:
RA: 206.06 (+1.40 -0.95 deg 90% PSF containment) J2000
Dec: 4.78  (+0.62 -0.56 deg 90% PSF containment) J2000

There was no Fermi-GBM onboard trigger around the event time of the
neutrino candidate. An automated, blind search for short gamma-ray bursts
below the onboard triggering threshold in Fermi-GBM also identified no
counterpart candidates. The GBM targeted search, the most sensitive,
coherent search for GRB-like signals, was run from +/-30 s around the
neutrino candidate time. From this search, no significant signal was found
related to IceCube-210210A.

We set upper limits on impulsive gamma-ray emission. Using the
representative soft, normal, and hard GRB-like templates
(arXiv:1612.02395), we report the following 3 sigma flux upper limits over
10-1000 keV (in units of 10^-7 erg/s/cm^2):

Timescale  soft     norm     hard
--------------------------------------

0.128 s: 8.5 12. 21.
1.024 s: 2.7 3.4 6.3
8.192 s: 1.1 1.6 3.4