{
  "id": "2009.09792",
  "version": "v1",
  "published": "2020-09-21T12:13:29.000Z",
  "updated": "2020-09-21T12:13:29.000Z",
  "title": "Neutrino emission during the $γ$-suppressed state of blazars",
  "authors": [
    "Emma Kun",
    "Imre Bartos",
    "Julia Becker Tjus",
    "Peter L. Biermann",
    "Francis Halzen",
    "György Mező"
  ],
  "comment": "5 pages, 4 figures",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "Despite the uncovered association of a high-energy neutrino with the apparent flaring state of blazar TXS 0506+056 in 2017, the mechanisms leading to astrophysical particle acceleration and neutrino production are still uncertain. Recent studies found that blazars in a $\\gamma$-flaring state are too sparse for neutrino production, making the multi-messenger observation of TXS 0506+056 difficult to explain. Here we show that the Fermi-LAT $\\gamma$ flux of another blazar, PKS 1502+106 was at a local minimum when IceCube recorded a coincident high-energy neutrino IC-190730A. This suggests the presence of a large target photon and proton density that helps produce neutrinos while temporarily suppressing observable $\\gamma$ emission. Using data from the OVRO 40-meter Telescope, we find that radio emission from PKS 1502+106 at the time of the coincident neutrino IC-190730A was in a high state, in contrast to other time periods when radio and $\\gamma$ fluxes are correlated. This points to an active outflow that is $\\gamma$-suppressed at the time of neutrino production. We find similar local $\\gamma$ suppression in other blazars, including the MAGIC flux of TXS 0506+056 and the Fermi-LAT flux of PKS B1424-418 at the time of coincident IceCube neutrino detections, further supporting the above model. Using temporary $\\gamma$-suppression, neutrino-blazar coincidence searches could be substantially more sensitive than previously assumed, enabling the identification of the origin of IceCube's diffuse neutrino flux possibly with already existing data.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2020-09-21T12:13:29.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "neutrino emission",
      "suppressed state",
      "diffuse neutrino flux possibly",
      "neutrino production",
      "icecubes diffuse neutrino flux"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 5,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}