Jul 12 – 23, 2021
Europe/Berlin timezone

Radio astronomy locates the neutrino origin in bright blazars

Jul 12, 2021, 6:00 PM
1h 30m


Talk MM | Multi-Messenger Discussion


Alexander Plavin (Astro Space Center of Lebedev Physical Institute)


High-energy astrophysical neutrinos have been observed by multiple telescopes in the last decade, but their sources still remained unknown. We address the problem of locating astrophysical neutrinos’ sources in a statistical manner. We show that blazars positionally associated with IceCube neutrino detections have stronger parsec-scale radio cores than the rest of the sample. The probability of a chance coincidence is only 4×10^-5 corresponding to a significance of 4.1σ. We explicitly list five strong radio blazars as highly probable sources of neutrinos above 200 TeV: 3C 279, NRAO 530, TXS 1308+326, PKS 1741-038, and PKS 2145+067. Turns out that there are at least 70 more radio-bright blazars that emit neutrinos of lower energies starting from TeVs. Moreover, we utilize continuous RATAN-600 monitoring of VLBI-selected blazars to find that radio flares at frequencies above 10 GHz coincide with neutrino arrival dates. The most pronounced example of such behavior is PKS 1502+106 that experienced a major flare in 2019. We conclude that the entire IceCube astrophysical neutrino flux derived from muon-track analyses may be explained by blazars, that is AGNs with bright Doppler-boosted jets. High-energy neutrinos can be produced in photohadronic interactions within parsec-scale relativistic jets. Radio-bright blazars associated with neutrino detections have very diverse gamma-ray properties, which suggests that gamma-rays and neutrinos may be produced in different regions of blazars and not directly related. A narrow jet viewing angle is, however, required to detect either of them.


AGN; blazar; neutrinos; relativistic jets; radio emission; VLBI

Subcategory Experimental Results

Primary authors

Alexander Plavin (Astro Space Center of Lebedev Physical Institute) Dr Yuri Kovalev Dr Yuri Kovalev Sergey Troitsky (INR, Moscow)

Presentation materials