ANTARES Search for Point Sources of Neutrinos Using Astrophysical Catalogs: A Likelihood Analysis

Abstract

[EN] A search for astrophysical pointlike neutrino sources using the data collected by the ANTARES detector between 2007 January 29 and 2017 December 31 is presented. A likelihood method is used to assess the signicance of an excess of muon neutrinos inducing track-like events in correlation with the location of a list of possible sources. Different sets of objects are tested in the analysis: (a) a subsample of the Fermi 3LAC catalog of blazars, (b) a jet- obscured population of active galactic nuclei, (c) a sample of hard X-ray selected radio galaxies, (d) a star-forming galaxy catalog, and (e) a public sample of 56 very-high-energy track events from the IceCube experiment. None of the tested sources shows a signi¿cant association with the sample of neutrinos detected by ANTARES. The smallest p-value is obtained for the catalog of radio galaxies with an equal-weights hypothesis, with a pre-trial p- value equivalent to a 2.8sigma excess, which is equivalent to 1.6sigma post-trial. In addition, the results of a dedicated analysis for the blazar MG3 J225517+2409 are also reported: this source is found to be the most signi¿cant within the Fermi 3LAC sample, with five ANTARES events located less than one degree from the source. This blazar showed evidence of ¿aring activity in Fermi data, in spacetime coincidence with a high-energy track detected by IceCube. An a posteriori signicance of 2.6sigma for the combination of ANTARES and IceCube data is reported.