Multiwavelength follow-up of a rare IceCube neutrino multiplet

• Published in: Astronomy & Astrophysics
• Main Authors: Aartsen, M. G., Bellm, E., IceCube Collaboration, ASAS-SN Collaboration, Astrophysical Multimessenger Observatory Network Collaboration, Fermi LAT Collaboration, HAWC Collaboration, LCO Collaboration, MASTER Collaboration, Swift Collaboration, VERITAS Collaboration
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: EDP Sciences 2017
• Subjects: Astroparticle physics; Neutrinos; Gamma-ray burst; Supernovae; Galaxies: active; X-rays: bursts; National Science Foundation Office of Polar Programs
• Online Access: https://doi.org/10.1051/0004-6361/201730620

On February 17, 2016, the IceCube real-time neutrino search identified, for the first time, three muon neutrino candidates arriving within 100 s of one another, consistent with coming from the same point in the sky. Such a triplet is expected once every 13.7 years as a random coincidence of background events. However, considering the lifetime of the follow-up program the probability of detecting at least one triplet from atmospheric background is 32%. Follow-up observatories were notified in order to search for an electromagnetic counterpart. Observations were obtained by Swift's X-ray telescope, by ASAS-SN, LCO and MASTER at optical wavelengths, and by VERITAS in the very-high-energy gamma-ray regime. Moreover, the Swift BAT serendipitously observed the location 100 s after the first neutrino was detected, and data from the Fermi LAT and HAWC observatory were analyzed. We present details of the neutrino triplet and the follow-up observations. No likely electromagnetic counterpart was detected, and we discuss the implications of these constraints on candidate neutrino sources such as gamma-ray bursts, core-collapse supernovae and active galactic nucleus flares. This study illustrates the potential of and challenges for future follow-up campaigns. © ESO 2017. Received 14 February 2017; accepted 30 July 2017. Neil Gehrels sadly died during the late stage of the production of this paper. As Swift PI he was an enthusiastic supporter of multi-messenger observations; he will be sorely missed. The IceCube Collaboration acknowledges the support from the following agencies: US National Science Foundation - Office of Polar Programs, US National Science Foundation - Physics Division, University of Wisconsin Alumni Research Foundation, the Grid Laboratory of Wisconsin (GLOW) grid infrastructure at the University of Wisconsin - Madison, the Open Science Grid (OSG) grid infrastructure; US Department of Energy, and National Energy Research Scientific Computing Center, the Louisiana Optical Network Initiative (LONI) ...