GCN Circular 21432
Subject
LIGO/Virgo G296853: IceCube neutrino observations
Date
2017-08-09T10:36:33Z (7 years ago)
From
Stefan Countryman at LIGO Scientific Collaboration <stefan.countryman@ligo.org>
I. Bartos, S. Countryman (Columbia), C. Finley (U Stockholm), E. Blaufuss
(U Maryland), R. Corley, Z. Marka, S. Marka (Columbia) on behalf of the
IceCube Collaboration
We searched IceCube online track-like neutrino candidates (GFU) detected in
a [-500,500] second interval about the LIGO-Virgo trigger G296853. We
compared the candidate source directions of 4 temporally-coincident
neutrinos to the BAYESTAR skymap, with the following parameters:
# dt[s] RA[deg] Dec[deg] E[TeV] Sigma[deg]
------------------------------------------------------------------
1. -310.02 65.9 -5.2 1.11 0.5
2. -128.45 74.0 -29.2 52.68 0.2
3. 361.60 164.0 -14.6 20.50 0.5
4. 438.49 121.1 -64.8 81.83 2.1
(dt--time from GW in [seconds]; RA/Dec--sky location in [degrees];
E--reconstructed secondary muon energy in [TeV]; Sigma--uncertainty of
direction reconstruction in [degrees])
The analysis found NO COINCIDENT ONLINE TRACK-LIKE NEUTRINO CANDIDATES
detected by IceCube within the 500 second window surrounding G296853 within
the BAYESTAR skymap.
A coincident neutrino-GW skymap has been posted to GraceDB (<
https://gracedb.ligo.org/apiweb/events/G296853/files/
coinc_skymap_initial_icecube.png,0>). A JSON-formatted list of the above
neutrinos can be downloaded from GraceDB at: <https://gracedb.ligo.org/
apiweb/events/G296853/files/IceCubeNeutrinoList.json,0>
In addition, we are performing coincident searches with other IceCube data
streams, including the high-energy starting events (HESE) and Supernova
triggers. HESE events have typical energies > 60 TeV and start inside the
detector volume, leading to a relatively pure event sample with a high
fraction of astrophysical neutrinos. The SN trigger system is sensitive to
sudden increases in photomultiplier counts across the detector, which could
indicate a burst of MeV neutrinos. We will submit separate GCN circulars
if coincident HESE or SN triggers are found.
The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector
operating at the geographic South Pole, Antarctica. For a description of
the IceCube realtime alert system, please refer to <
http://adsabs.harvard.edu/cgi-bin/bib_query?arXiv:1610.01814>; for more
information on joint neutrino and gravitational wave searches, please refer
to <http://adsabs.harvard.edu/cgi-bin/bib_query?arXiv:1602.05411>.