TITLE: GCN CIRCULAR NUMBER: 25192 SUBJECT: LIGO/Virgo S190728q: One neutrino candidate from IceCube search DATE: 19/07/28 10:06:18 GMT FROM: Raamis Hussain at IceCube IceCube Collaboration (http://icecube.wisc.edu/) reports: A search for track-like muon neutrino events detected by IceCube consistent with the sky localization of gravitational-wave candidate S190728q in a time range of 1000 seconds [1] centered on the alert event time (2019-07-28 06:36:50.529 UTC to 2019-07-28 06:53:30.529 UTC) has been performed. During this time period IceCube was collecting good quality data. The search is a maximum likelihood analysis which searches for a generic point-like neutrino source coincident with the given GW skymap [2]. One track-like event is found in spatial and temporal coincidence with the gravitational-wave candidate S190728q calculated from the map circulated in the 4-Initial notice. This represents an overall p-value of 0.03 (1.84 sigma). An earlier search (GCN 25185) based on preliminary information of S190728q yielded no significant p-values for the worse GW localization [3]. Properties of the coincident events are shown below. dt ra (deg) dec (deg) Angular Uncertainty(deg) p-value(generic transient) ---------------------------------------------------------------------------------------------- -360 312.87 5.85 4.81 0.039 where: dt = Time offset (sec) of track event with respect to GW trigger. Angular uncertainty = Angular uncertainty of track event: the radius of a circle representing 90% CL containment by area. p-value = the p-value for this specific track event RA & Dec = Right ascension and declination in degrees quoted in J2000 epoch 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@icecube.wisc.edu [1] Baret et al., Astroparticle Physics 35, 1 (2011) [2] Braun et al., Astroparticle Physics 29, 299 (2008) [3] GCN 25185: https://gcn.gsfc.nasa.gov/gcn3/25185.gcn3