[vsnet-grb-info 21302] FACT follow-up of IceCube20181023A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23401
SUBJECT: FACT follow-up of IceCube20181023A
DATE:    18/10/31 15:24:39 GMT
FROM:    Daniela Dorner at U of Wuerzburg  <dorner at astro.uni-wuerzburg.de>

A. Biland (ETH Zurich) reports on behalf of the FACT Collaboration:

On Tue 23 Oct 18 16:38:11 UTC, the IceCube Collaboration reported the
detection of a high-energy neutrino (run number 131653, event number
53411354). An updated position was communicated by IceCube on 18/10/23
19:38:53 GMT (GCN #23375). 

FACT observed the updated position for one hour on 2018/10/26. The
automatic Quick Look Analysis (http://www.fact-project.org/monitoring)
does not show any significant signal from the observed position. 

The weather conditions during the observation were not ideal and the
zenith distance range during the observation was from 52 degree to 63
degree. 

An analysis of these data yields an upper limit of 84% of the flux of
the Crab Nebula with a confidence level of 99%. 

Contact person: Daniela Dorner (dorner at astro.uni-wuerzburg.de) 

The First G-APD Cherenkov Telescope (FACT) is an imaging air Cherenkov
telescope monitoring blazars at TeV energies. It is located in the
Observatorio del Roque de los Muchachos on the Canary Island La Palma.