TITLE: GCN CIRCULAR NUMBER: 28592 SUBJECT: IceCube-201007A: No significant detection in HAWC DATE: 20/10/09 18:10:43 GMT FROM: Alberto Carraminana at AzTEC Alberto Carramiñana (INAOE) reports on behalf of the HAWC collaboration (http://www.hawc-observatory.org/collaboration): On 2020/10/07 22:01:49 UTC, the IceCube collaboration reported a track-like very-high-energy event that has a high probability of being an astrophysical neutrino, IceCube-201007A. Location is at RA: 265.17 (+/-0.52 deg 90% PSF containment) J2000 Dec: 5.34 (+0.32/-0.23 deg 90% PSF containment) J2000 (GCN circular 28575). We performed two types of analyses for the follow-up. The first is for a steady source in archival data and the second is a search for a transient source. We assume a power-law spectrum with an index of -2.3 for both analyses. - Search for a steady source in archival data: The archival data spans from November 2014 to June 2019. We searched inside the reported IceCube error region. The most significant location, with p-value 1.29e-02 (3.70e-02 post-trials), is at RA 264.86 deg, Dec +5.23 deg (±0.15 deg 68% containment) J2000. We set a time-integrated 95% CL upper limit on gamma rays at the maximum position of: E^2 dN/dE = 2.57e-13 (E/TeV)^-0.3 TeV.cm^-2.s^-1 - Search for a transient source. The IceCube event was in our field of view at the time reported. Data acquisition started on 2020/10/07 20:06:38 UTC and ended 2020/10/08 01:58:29 UTC. The most significant location, with p-value 3.97e-01 (7.71e-01 post-trials), is at RA 265.25 deg, Dec +5.34 deg (±0.27 deg 68% containment) J2000. We set a time-integrated 95% CL upper limit at the position of maximum significance of: E^2 dN/dE = 6.47e-12 (E/TeV)^-0.3 TeV.cm^-2.s^-1 HAWC is a very-high-energy gamma-ray observatory operating in Central Mexico at latitude 19 deg. north. Operating day and night with over 95% duty cycle, HAWC has an instantaneous field of view of 2 sr and surveys 2/3 of the sky every day. It is sensitive to gamma rays from 300 GeV to 100 TeV.