Energy dissipation of energetic electrons in the inhomogeneous intergalactic medium during the epoch of reionization

TL;DR

This paper investigates how energetic electrons lose energy in the inhomogeneous intergalactic medium during reionization, considering atomic processes and inverse Compton scattering, revealing dependencies on initial energy and local density.

Contribution

It introduces a detailed, time-dependent model of electron energy dissipation during reionization, including non-local effects and relativistic atomic cross sections, with an open-source code release.

Findings

Energy loss involves local atomic and non-local IC processes.

Energy partition depends on initial electron energy.

Baryon overdensity influences energy distribution.

Abstract

We explore a time-dependent energy dissipation of the energetic electrons in the inhomogeneous intergalactic medium (IGM) during the epoch of cosmic reionization. In addition to the atomic processes we take into account the Inverse Compton (IC) scattering of the electrons on the comic microwave background (CMB) photons, which is the dominant channel of energy loss for the electrons with energies above a few MeV. We show that: (1) the effect on the IGM has both local (atomic processes) and non-local (IC radiation) components; (2) the energy distribution between Hydrogen and Helium ionizations depends on the initial electron energy; (3) the local baryon overdensity significantly affects the fractions of energy distributed in each channel; and (4) the relativistic effect of atomic cross section become important during the epoch of cosmic reionization. We release our code as open source for further modification by the community.