ANTARES search for neutrinos from TXS0506+056, reported as a source of high-energy neutrinos by the IceCube Neutrino Observatory

Two papers published this week in the journal Science have for the first time provided evidence for a known blazar as a source of high-energy neutrinos detected by the IceCube observatory. The papers are available at this address and here. This blazar, designated by astronomers as TXS 0506+056, was first singled out following a neutrino alert sent by IceCube on Sept. 22, 2017 (IC170922A). More information are given on the IceCube website (see also the Press Conference).

Thanks to sharing of information by the IceCube collaboration before the public release, the ANTARES Collaboration was able to perform three different searches for neutrino candidates associated with IC170922A or from the direction of TXS 0506+056. The first one refers to the online follow-up associated with IC170922A. The second is based on the standard likelihood method employed by the Collaboration to search for point-like neutrino sources. The third uses the information from the time-dependent analysis performed by the IceCube collaboration, which reports a bursting activity centered on December 13, 2014, as input for an ANTARES dedicated analysis. The results of these searches are presented in an article submitted to The Astrophysical Journal, available here and on arXiv. The online follow-up and the time-dependent analysis yield no events related to the source. The time-integrated study performed over a period from 2007 to 2017 fits 1.03 signal events, which corresponds to a p-value of 3.4%. TXS 0506+056 consequently appears as the third most significant source among the 107 scrutinised by ANTARES. Accounting for all trials, the p-value rises up to 87%.