Search for Multi-flare Neutrino Emissions in 10 yr of IceCube Data from a Catalog of Sources
Astrophysical Journal Letters American Astronomical Society 920:2 (2021) L45-L45
Authors:
R Abbasi, M Ackermann, J Adams, Ja Aguilar, M Ahlers, M Ahrens, C Alispach, Aa Alves, Nm Amin, R An, K Andeen, T Anderson, G Anton, C Argüelles, Y Ashida, S Axani, X Bai, Ab V., A Barbano, Sw Barwick, B Bastian, V Basu, S Baur, R Bay, Jj Beatty, Kh Becker, Jb Tjus, C Bellenghi, S Benzvi, D Berley, E Bernardini, Dz Besson, G Binder, D Bindig, E Blaufuss, S Blot, M Boddenberg, F Bontempo, J Borowka, S Böser, O Botner, J Böttcher, E Bourbeau, F Bradascio, J Braun, S Bron, J Brostean-Kaiser, S Browne, A Burgman, Rt Burley
Abstract:
A recent time-integrated analysis of a catalog of 110 candidate neutrino sources revealed a cumulative neutrino excess in the data collected by IceCube between 2008 April 6 and 2018 July 10. This excess, inconsistent with the background hypothesis in the Northern Hemisphere at the 3.3σ level, is associated with four sources: NGC 1068, TXS 0506+056, PKS 1424+240, and GB6 J1542+6129. This Letter presents two time-dependent neutrino emission searches on the same data sample and catalog: a point-source search that looks for the most significant time-dependent source of the catalog by combining space, energy, and time information of the events, and a population test based on binomial statistics that looks for a cumulative time-dependent neutrino excess from a subset of sources. Compared to previous time-dependent searches, these analyses enable a feature to possibly find multiple flares from a single direction with an unbinned maximum-likelihood method. M87 is found to be the most significant time-dependent source of this catalog at the level of 1.7σ post-trial, and TXS 0506+056 is the only source for which two flares are reconstructed. The binomial test reports a cumulative time-dependent neutrino excess in the Northern Hemisphere at the level of 3.0σ associated with four sources: M87, TXS 0506+056, GB6 J1542+6129, and NGC 1068.
