[vsnet-grb-info 21281] Search for counterparts to IceCube-181023A with IceCube

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23380
SUBJECT: Search for counterparts to IceCube-181023A with IceCube
DATE:    18/10/24 21:59:48 GMT
FROM:    Alex Pizzuto at ICECUBE/U of Wisconsin  <pizzuto at wisc.edu>

The IceCube Collaboration (http://icecube.wisc.edu/) reports:

IceCube has performed a search for additional track-like muon 
neutrino events arriving from the direction of IceCube-181023A 
(https://gcn.gsfc.nasa.gov/gcn3/23375.gcn3) in a time range of 
2 days centered on the alert event time (2018-10-22 16:37:32 UTC 
to 2018-10-24 16:37:32 UTC) during which IceCube was collecting 
good quality data. Excluding the event that prompted the alert, 2 
additional track-like events are found in spatial coincidence with 
the 90% PSF containment of IceCube-181023A. We find that these 
data are well described by atmospheric background expectations, with 
a p-value of 1.0. Accordingly, these data would represent a time-integrated 
muon-neutrino flux upper limit assuming an E^-2 spectrum (E^2 dN/dE) at 
the 90% CL of 9.71 x 10^-5 TeV cm^-2  for this observation period.

A subsequent search was performed to include the previous month of 
data (2018-09-23 16:37:32 UTC to 2018-10-24 16:37:32 UTC). In 
this case, we report a p-value of 1.0, consistent with no significant 
excess of track events, and a corresponding time-integrated 
muon-neutrino flux upper limit assuming an E^-2 spectrum (E^2 dN/dE) 
at the 90% CL of 2.66 x 10^-4 TeV cm^-2.

The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector 
operating at the geographic South Pole, Antarctica.  The IceCube realtime 
alert point of contact can be reached at roc at icecube.wisc.edu