The Blazar Hadronic Code Comparison Project

TL;DR

This paper presents the first systematic comparison of different computational codes used in modeling hadronic processes in blazar jets, aiming to understand uncertainties in these complex simulations.

Contribution

It provides a comprehensive benchmarking of blazar hadronic codes, highlighting differences and uncertainties in modeling proton-photon interactions and associated emissions.

Findings

Identified key discrepancies between different hadronic codes.

Quantified uncertainties in neutrino and gamma-ray emission predictions.

Established a foundation for improving model consistency.

Abstract

Blazar hadronic models have been developed in the past decades as an alternative to leptonic ones. In hadronic models the gamma-ray emission is associated with synchrotron emission by protons, and/or secondary leptons produced in proton-photon interactions. Together with photons, hadronic emission models predict the emission of neutrinos that are therefore the smoking gun for acceleration of relativistic hadrons in blazar jets. The simulation of proton-photon interactions and all associated radiative processes is a complex numerical task, and different approaches to the problem have been adopted in the literature. So far, no systematic comparison between the different codes has been performed, preventing a clear understanding of the underlying uncertainties in the numerical simulations. To fill this gap, we have undertaken the first comprehensive comparison of blazar hadronic codes, and the results from this effort will be presented in this contribution.