High-Energy Neutrino Production through Photopion Processes in Blazars

TL;DR

This paper models high-energy neutrino production in blazars by analyzing their radiation fields and predicts detectable neutrino fluxes for km^2 telescopes, highlighting the role of external radiation in FSRQs.

Contribution

It introduces a method to estimate neutrino fluxes from blazars based on their spectral energy distribution and external radiation fields, providing new predictions for neutrino detection.

Findings

Neutrino flux from blazars like 3C 279 is detectable with km^2 telescopes.

External radiation fields are key targets for photomeson neutrino production in FSRQs.

BL Lac objects are weaker neutrino sources due to different emission mechanisms.

Abstract

The measured spectral energy distribution and variability time scale are used to determine the radiation and magnetic-field energy densities in the relativistic plasma that forms the gamma-ray emitting jet in the blazar 3C 279. Assuming that protons are accelerated as efficiently as electrons to a maximum energy determined by the size and magnetic field of the emitting region, we calculate the emissivity of neutrinos produced by protons that interact with the external radiation field intercepted by the jet. The external radiation field provides the most important target photons for photomeson production of high-energy neutrinos in flat spectrum radio quasars (FSRQs). Because of photomeson interactions with this field, km^2 neutrino telescopes are predicted to detect > 0.1-1 neutrinos per year from blazars such as 3C 279. BL Lac objects are weaker neutrino sources if, as widely thought, their gamma-ray emission is due to Compton-scattered synchrotron (SSC) radiation.