TXS 0506+056-like blazar sources and their role as possible neutrino emitters

TL;DR

This study investigates blazar sources similar to TXS 0506+056 to understand their potential as neutrino emitters, analyzing their properties, spectral energy distributions, and neutrino flux prospects.

Contribution

The paper introduces a method to select and analyze blazar candidates similar to TXS 0506+056, focusing on their emission processes and neutrino detectability.

Findings

High energy emission dominated by leptonic processes.

Many candidates show high accretion rates typical of FSRQs.

VHE and neutrino fluxes are generally undetectable with current instruments.

Abstract

The interest in blazars as candidate neutrino emitters grew after the 3$\sigma$ evidence for a contemporaneous joint photon and neutrino emission from the flaring blazar TXS 0506+056 in 2017. Blazars, a class of extragalactic sources with relativistic jets pointing toward Earth, present a broadband emission interpretable via leptonic and hadronic processes, the latter relevant for proton acceleration and neutrino production. Several emission models have been developed to explain this multi-messenger observation, but the details of the neutrino production and the nature of TXS 0506+056 are not yet fully understood. In this work we investigate the properties of sources similar to TXS 0506+056. We select a sample of blazars from the Fermi 4LAC-DR2 catalog by constraining a number of key parameters in ranges centered on TXS 0506+056 values. We estimate their disk accretion efficiency and model their spectral energy distribution (SED) in terms of lepto-hadronic emission, gaining information respectively on the potential similarity of their environment with that of TXS 0506+056 and on their neutrino flux and detectability prospects at TeV energies. Our study shows the candidates' high energy emission to be dominated by leptonic processes. Part of them also show a high accretion rate, characteristic of FSRQs. For these sources, the very high energy (VHE) and neutrino fluxes appear undetectable by current and future instruments in an average emission state.