ASAS-SN follow-up of IceCube high-energy neutrino alerts

Abstract

We report on the search for optical counterparts to IceCube neutrino alerts released between April 2016 and August 2021 with the All-Sky Automated Survey for SuperNovae (ASAS-SN). Despite the discovery of a diffuse astrophysical high-energy neutrino flux in 2013, the source of those neutrinos remains largely unknown. Since 2016, IceCube has published likely-astrophysical neutrinos as public realtime alerts. Through a combination of normal survey and triggered target-of-opportunity observations, ASAS-SN obtained images within 1 hour of the neutrino detection for 20% (11) of all observable IceCube alerts and within one day for another 57% (32). For all observable alerts, we obtained images within at least two weeks from the neutrino alert. ASAS-SN provides the only optical follow-up for about 17% of IceCube's neutrino alerts. We recover the two previously claimed counterparts to neutrino alerts, the flaring-blazar TXS 0506+056 and the tidal disruption event AT2019dsg. We investigate the light curves of previously-detected transients in the alert footprints, but do not identify any further candidate neutrino sources. We also analysed the optical light curves of Fermi 4FGL sources coincident with high-energy neutrino alerts, but do not identify any contemporaneous flaring activity. Finally, we derive constraints on the luminosity functions of neutrino sources for a range of assumed evolution models.

References in corpus (13)

• The Supernova -- Gamma-Ray Burst Connection
• The Zwicky Transient Facility: Data Processing, Products, and Archive
• The All-Sky Automated Survey for Supernovae (ASAS-SN) Light Curve Server v1.0
• IceCube-Gen2: The Window to the Extreme Universe
• Time-integrated Neutrino Source Searches with 10 years of IceCube Data
• The contribution of Fermi-2LAC blazars to the diffuse TeV-PeV neutrino flux
• Photohadronic origin of $\gamma$-ray BL Lac emission: implications for IceCube neutrinos
• Revealing the Supernova--Gamma-Ray Burst Connection with TeV Neutrinos
• Candidate Tidal Disruption Event AT2019fdr Coincident with a High-Energy Neutrino
• Radio Observations of an Ordinary Outflow from the Tidal Disruption Event AT2019dsg
• Multi-wavelength and neutrino emission from blazar PKS 1502+106
• Neutrinos from tidal disruption events
• High-resolution VLBI observations of and modelling the radio emission from the TDE AT2019dsg

Cited by in corpus (4)

• The Spectroscopic Classification of Astronomical Transients (SCAT) Survey: Overview, Pipeline Description, Initial Results, and Future Plans
• Neutrino follow-up with the Zwicky Transient Facility: Results from the first 24 campaigns
• The ASAS-SN Bright Supernova Catalog -- V. 2018-2020
• High-energy neutrinos from choked-jet supernovae: Searches and implications