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 collection 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.
Gonzalez et al. (Wed,) studied this question.