A 3D Monte Carlo calculation of the inverse Compton emission from the Sun and stars in presence of magnetic and electric fields

TL;DR

This paper develops a 3D Monte Carlo simulation method to model inverse Compton emission from the Sun and stars, accounting for magnetic and electric fields, to improve interpretation of gamma-ray observations.

Contribution

It introduces a general approach for simulating anisotropic inverse Compton scattering in 3D with magnetic and electric fields, extending previous models.

Findings

Predicted inverse Compton emission profiles for the Sun.

Demonstrated the impact of magnetic fields on gamma-ray emission.

Provided a framework for future observational interpretation.

Abstract

The solar steady emission in gamma rays is due to the interactions of Galactic cosmic rays with the solar atmosphere and with the low-energy solar photon field via inverse Compton scattering. The emission is sensitive to the magnetic field nearby the Sun and to the cosmic-ray transport in the magnetic field in the inner solar system. Modeling the inverse Compton emission in the presence of a magnetic field is therefore crucial to better interpret the observations. In a previous work we have presented a comprehensive calculation of the secondary productions due to the collision of cosmic rays with the solar atmosphere in presence of magnetic fields. In this paper, we present a general approach to calculate the (anisotropic) inverse Compton scattering in a 3D Monte Carlo simulation, also in presence of magnetic and electric fields. After a short review of the scattering process of photons with electrons, examples of inverse Compton emission are presented, including the predictions for the Sun.