Search for neutrino counterpart to the blazar PKS0735+178 potentially associated with IceCube-211208A and Baikal-GVD-211208A with the KM3NeT neutrino detectors.

ATel #15290; F. Filippini, G. Illuminati (Univ. Bologna, INFN Bologna), A. Heijboer, C. Gatius, R. Muller (Nikhef), D. Dornic, F. Huang, S. Le Stum (CPPM, Aix-Marseille Univ.), J. Palacios González (IFIC), S. Celli, A. Zegarelli (Univ. La Sapienza, INFN Roma), R. Coniglione (INFN LNS), D. Samtleben (Nikhef, Leiden Univ.), Y. Y. Kovalev, A. Plavin (ASC Lebedev) on behalf of the KM3NeT Collaboration
on 21 Mar 2022; 10:54 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Damien Dornic (dornic@cppm.in2p3.fr)

Tweet

Using data from the KM3NeT neutrino detectors, we have performed a follow-up analysis of the potential correlation between one track event IceCube-211208A (GCN #31191>) and a flare of the blazar PKS0735+178. This blazar was observed during a strong flare in gamma rays (ATel #15099, ATel #15129), X-rays (ATel #15102, ATel #15108, ATel #15109, ATel #15113, ATel #15130), optical (ATel #15098, ATel #15100, ATel #15132, ATel #15136, ATel #15148) and radio (ATel #15105) bands. This flare covers the full month of December 2021. No additional neutrino events from the direction of the alert have been reported by IceCube (GCN #31195) and ANTARES (ATel #15106). Baikal-GVD has also reported an observation of a high-energy cascade neutrino in coincidence with this flaring blazar and IceCube-211208A (ATel #15112). Baksan has also reported one muon neutrino in spatial coincidence on December 4, 2021 (ATel #15143). During a +/- 1 day time-window centered on the IceCube event time, no up-going muon neutrino candidate was recorded by the ARCA detector within an MDP optimized search cone of 1.4 deg radius centered on the blazar coordinates. During this time window, the source remains 42.3% visible [2021/12/08T08h19 - 18h29 and 2021/12/09T08h15 - 18h25]. An additional search over an extended time window covering the full month of December 2021 has yielded one up-going muon neutrino candidate in coincidence in ARCA with an estimated neutrino energy of ~18 TeV, at Dec 15 08h51’31.6 from the direction (RA=113.5 deg, DEC=17.6 deg, Error (50 %) = 1.8 deg). The p-value of this association is 0.14. The 5 - 95% neutrino energy range where this search is sensitive is 9 TeV - 11 PeV. A similar approach has been performed using the ORCA data sensitive to lower energy events (200 GeV - 5 TeV). In both search time windows, no up-going muon neutrino candidate has been recorded (search cones of 4.2 / 2.3 deg for the short and extended search time windows). KM3NeT is a large undersea (Mediterranean Sea) infrastructure hosting two neutrino detectors, sensitive to astrophysical neutrinos in the GeV-PeV energy range: ARCA at high energy and ORCA at low energy. 8 and 10 detection units are in operation in ARCA and ORCA, respectively.