Simulating radio emission from air showers with CoREAS

TL;DR

This paper introduces CoREAS, a comprehensive Monte Carlo simulation tool for radio emission from air showers, accurately modeling complex emission mechanisms across a wide frequency spectrum without assumptions.

Contribution

It presents a parameter-free, detailed simulation method for radio signals from air showers, incorporating the full electron-positron distributions and Cherenkov effects at high frequencies.

Findings

Simulations cover frequency ranges from tens of MHz to GHz.

High-frequency emission features due to Cherenkov effects are characterized.

CoREAS accurately models the complex emission mechanisms of air showers.

Abstract

CoREAS is a Monte Carlo code for the simulation of radio emission from extensive air showers. It implements the endpoint formalism for the calculation of electromagnetic radiation directly in CORSIKA. As such, it is parameter-free, makes no assumptions on the emission mechanism for the radio signals, and takes into account the complete complexity of the electron and positron distributions as simulated by CORSIKA. In this article, we illustrate the capabilities of CoREAS with simulations carried out in different frequency ranges from tens of MHz up to GHz frequencies, and describe in particular the emission characteristics at high frequencies due to Cherenkov effects arising from the varying refractive index of the atmosphere.