Aleksandr, PlavinBurenin, R.A.Kovalev, Y.Y.Lutovinov, A.A.Starobinsky, A.A.Troitsky, S.V.Zakharov, E.I.2024-06-212024-05-01Aleksandr, Plavin, R.A. Burenin, Y.Y. Kovalev, A.A. Lutovinov, A.A. Starobinsky, S.V. Troitsky, E.I. Zakharov. "Hard X-ray emission from blazars associated with high-energy neutrinos." J. Cosmol. Astropart. Phys. 2024, no. 05 (2024): 133. DOI: 10.1088/1475-7516/2024/05/1331475-7516https://nrs.harvard.edu/URN-3:HUL.INSTREPOS:37379185Bright blazars were found to be prominent neutrino sources, and a number of IceCube events were associated with them. Evaluating high-energy photon emission of such blazars is crucial for better understanding of the processes and regions where neutrinos are produced. Here, we focus on hard X-ray emission observed by the SRG/ART-XC telescope, by the Swift/BAT imager, and by the INTEGRAL/IBIS telescope. Their energy range ≳10 keV is well-suited for probing photons that potentially participate in neutrino production by interacting with ultrarelativistic protons. We find that neutrino-associated blazars tend to demonstrate remarkably strong X-ray emission compared to other VLBI blazars in the sky. Both neutrinos and hard X-rays are found to come from blazars at cosmological distances z ∼ 1, and are boosted by relativistic beaming that makes it possible to detect them on Earth. Our results suggest that neutrinos are produced within compact blazar jets, with target X-ray photons emitted from accelerated jet regions.en-USJournal Article2024-06-2110.1088/1475-7516/2024/05/133