ASKAP and VLASS Search for a Radio-continuum Counterpart of Ultra-high-energy Neutrino Event KM3-230213A

Filipović MD, Smeaton ZJ, Bradley AC, Dobie D, Koribalski BS, Kothes R, Rudnick L, Ahmad A, Alsaberi RZ, Anderson CS, Barnes LA, Breuhaus M, Crawford EJ, Dai S, Gordon YA, Gupta N, Hopkins AM, Leahy D, Luken KJ, McClure-Griffiths N, Michałowski MJ, Sasaki M, Tothill NF, Umana GM, Vernstrom T, West J (2025)

Publication Type: Journal article

Publication year: 2025

Journal

Astrophysical Journal Letters American Astronomical Society

Book Volume: 984

Article Number: L52

Journal Issue: 2

DOI: 10.3847/2041-8213/adca37

Abstract

We present the results of an Australian Square Kilometre Array Pathfinder (ASKAP) 944 MHz and Very Large Array Sky Survey (VLASS) 3 GHz search for a radio-continuum counterpart of the recent ultra-high-energy neutrino event, KM3-230213A. Using ASKAP, we catalog 1052 radio sources within the 1 . ° 5 radius search area (68% certainty region) around the particle’s calculated origin, 10 of which we classify as blazar candidates based on their radio spectra. The most prominent radio source in the search area is the nearby spiral galaxy UGCA 127 (nicknamed Phaedra, from Greek ϕαiδρα, a Cretan princess of Greek mythology, derived from Phaidros, Greek φαιδρoς, meaning “bright”). Its nonthermal radio spectrum classifies it as a nonblazar active galactic nucleus. We also present an extended radio source, WISEA J061715.89-075455.4 (nicknamed Hebe, from Greek Hβη, the Greek goddess of youth), located only ∼7 ′ from the geometric center of the search area, with a very unusual, highly polarized compact component. Finally, we present a strong radio source, EMU J062248-072246 (nicknamed Narcissus, from Greek Nαρκισσoζ, a self-absorbed hunter from Thespiae in Boeotia), which can be modeled either with a synchrotron self-absorbed spectrum or synchrotron emission from thermal electrons. It exhibits ∼25% flux density variability over the ∼5 yr VLASS 3 GHz survey.

Authors with CRIS profile

Manami Sasaki Professur für Multiwellenlängenastronomie

Involved external institutions

University of Western Sydney AU Australia (AU) University of Sydney (USYD) AU Australia (AU) National Research Council / Conseil national de recherches Canada CA Canada (CA) University of Minnesota (UMN) US United States (USA) (US) Australian National University (ANU) AU Australia (AU) Institut national de physique nucléaire et de physique des particules (IN2P3) FR France (FR) University of Wisconsin - Madison US United States (USA) (US) Commonwealth Scientific and Industrial Research Organisation (CSIRO) AU Australia (AU) Macquarie University AU Australia (AU) University of Calgary CA Canada (CA) Adam Mickiewicz University / Uniwersytet im. Adama Mickiewicza w Poznaniu (UAM) PL Poland (PL) National Institute for Astrophysics / Istituto Nazionale Astrofisica (INAF) IT Italy (IT)

How to cite

APA:

Filipović, M.D., Smeaton, Z.J., Bradley, A.C., Dobie, D., Koribalski, B.S., Kothes, R.,... West, J. (2025). ASKAP and VLASS Search for a Radio-continuum Counterpart of Ultra-high-energy Neutrino Event KM3-230213A. Astrophysical Journal Letters, 984(2). https://doi.org/10.3847/2041-8213/adca37

MLA:

Filipović, M. D., et al. "ASKAP and VLASS Search for a Radio-continuum Counterpart of Ultra-high-energy Neutrino Event KM3-230213A." Astrophysical Journal Letters 984.2 (2025).

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