Measurement of the Iron Spectrum with the MAGIC Telescopes

TL;DR

This paper demonstrates the use of MAGIC telescopes and the direct Cherenkov technique to measure the iron cosmic ray spectrum at TeV energies, providing new insights into cosmic ray origins and acceleration.

Contribution

It introduces a novel application of the direct Cherenkov technique with ground-based MAGIC telescopes to identify and measure the iron cosmic ray spectrum at high energies.

Findings

Successful identification of iron-induced air showers

Extension of cosmic ray measurements to higher energies

Complementing space-based detector results

Abstract

Iron cosmic rays represent the most abundant heavy nuclei at energies above 1 TeV, with their production thought to be primarily originated by astrophysical sources. Therefore, measuring the iron spectrum provides crucial insights into the origin, acceleration, and propagation mechanisms of cosmic rays. While recent results from space-based detectors have revealed unexpected energy dependences in the GeV-TeV range, these measurements are limited by low statistics at higher energies. At energies above a few TeV, ground-based detectors, such as the Major Atmospheric Gamma Imaging Cherenkov (MAGIC) telescopes, become more effective due to their large collec- tion areas, enabling them to extend and complement the capabilities of space-borne instruments. In this work, we apply the so-called direct Cherenkov technique, which accounts for the radiation emitted by charged particles before the cascade develops in the atmosphere, with MAGIC to identify iron-induced air showers and distinguish them from those produced by lighter cosmic-ray species.