Multi-Messenger observations of the γ-ray blazar 4FGL J0658.6+0636 consistent with an IceCube high-energy neutrino

the Fermi-LAT, H.E.S.S., MAGIC, VERITAS, ZTF, TELAMON Collaboration

Research output: Contribution to journalConference articlepeer-review


The detection of cosmic neutrinos has raised many new questions in astroparticle physics, among the most compelling of which is the identification of cosmic neutrino emitters. After more than a decade of IceCube operations, the most promising neutrino astrophysical association remains the very-high-energy (VHE, > 100 GeV) blazar TXS 0506+056. Recently, on November 14, 2020 the IceCube observatory reported the detection of a well-reconstructed high-energy neutrino event, IceCube-201114A, with a high probability of being astrophysical. Within the 90% IceCube-201114A localization region only one known γ-ray (> 100 MeV) source is found. This is 4FGL J0658.6+0636, associated with the blazar NVSS J065844+063711. In these proceedings we present results from the rich multi-messenger campaign triggered by the IceCube-201114A neutrino detection, which has allowed us to collect simultaneous and quasi-simultaneous data for the γ-ray source potentially associated with the neutrino. NVSS J065844+063711 is a previously-known blazar with broadband properties resembling a high-synchrotron-peaked object, making it a promising TeV emitter. Indeed, the detection of very high-energy (VHE) photons (i.e., > 100 GeV) by the Fermi Large Area Telescope provides the first evidence of such emission from this object. It makes NVSS J065844+063711 the second VHE object found within the 90% confidence region of a well-reconstructed, high-energy IceCube event.

Original languageEnglish (US)
Article number955
JournalProceedings of Science
StatePublished - Mar 18 2022
Event37th International Cosmic Ray Conference, ICRC 2021 - Virtual, Berlin, Germany
Duration: Jul 12 2021Jul 23 2021

All Science Journal Classification (ASJC) codes

  • General


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