Hadronuclear interactions in the jet of low TeV luminosity AGN: Implications for the low-state very-high-energy gamma-ray emission

TL;DR

This paper investigates hadronuclear pp interactions in low TeV luminosity AGN jets, demonstrating their potential to produce detectable very-high-energy gamma-ray emission and explaining observed spectra.

Contribution

It introduces a one-zone pp model to explain VHE gamma-ray emission in low TeV luminosity AGNs, highlighting the significance of pp interactions previously neglected.

Findings

Gamma-ray emission from pp interactions can explain observed TeV spectra.

M 87, Mrk 421, and Mrk 501 are promising candidates for LHAASO detection.

pp interactions contribute to higher energy gamma-ray bands.

Abstract

In the study of radiation mechanisms of AGNs' jets, hadronuclear (pp) interactions are commonly neglected, because the number density of cold protons in the jet is considered insufficient. Very recently, our previous work proves that pp interactions in the low TeV luminosity AGNs, which have potential to generate detectable very-high-energy (VHE) emission, could be important. Based on this, the one-zone pp model is employed to study low-state quasi-simultaneous spectral energy distributions of a sample of low TeV luminosity AGNs in this work. Our modeling results show that the gamma-ray generated in pp interactions can explain the observed TeV spectra and has contribution to higher energy band that could be detected by the Large High Altitude Air Shower Observatory (LHAASO). In the sample, we suggest that M 87, Mrk 421 and Mrk 501 are the most likely objects to be detected by LHAASO in the near future. Other possible origins of VHE emission are also briefly discussed.