GCN Circular 21475
Subject
LIGO/Virgo G297595: IceCube neutrino observations
Date
2017-08-14T12:29:53Z (8 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
In an analysis completed at 2017-08-14 11:31:35 UTC, we searched IceCube online track-like neutrino candidates (GFU) detected in a [-500,500] second interval about the LIGO-Virgo trigger G297595. We compared the candidate source directions of 12 temporally-coincident neutrinos to the BAYESTAR skymap, with the following parameters:
# dt[s] RA[deg] Dec[deg] E[TeV] Sigma[deg]
------------------------------------------------------------------
1. -442.72 117.9 30.6 0.95 1.2
2. -362.65 6.8 49.6 1.20 0.9
3. -358.50 240.1 -16.8 22.79 0.3
4. -181.80 187.1 -66.2 35.08 0.3
5. -143.66 215.1 6.2 1.56 1.4
6. -42.69 264.3 -44.4 51.30 0.3
7. 99.62 85.0 -36.3 56.41 0.2
8. 174.83 280.2 22.6 1.05 0.9
9. 178.76 330.5 17.1 0.77 1.5
10. 202.04 291.7 36.2 0.78 0.8
11. 279.60 119.7 -15.8 18.31 0.7
12. 329.09 188.6 -5.4 1.30 1.0
(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 G297595 within the BAYESTAR skymap.
A coincident neutrino-GW skymap has been posted to GraceDB (<https://gracedb.ligo.org/apiweb/events/G297595/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/G297595/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>.