The Fermi Large Area Telescope as a cosmic-ray detector

Abstract

The Fermi Large Area Telescope is an international observatory conceived to study high energy gamma-rays from the universe. It is designed to identify and reconstruct electromagnetic showers and it can collect cosmic-ray electrons and positrons thanks to its triggering and filtering capabilities. The Fermi LAT collaboration has published several results on charged cosmic rays. We measured the inclusive spectrum of electrons and positrons from 7 GeV to 1 TeV and searched for anisotropies in the electron incoming direction. We have recently published a measurement of cosmic-ray positron-only and electron-only spectra for energies between 20 GeV and 200 GeV exploiting the Earthʼs magnetic field as a charge separator. In this work we describe the techniques and capabilities of the LAT as a cosmic-ray detector and review the recent results and their interpretations. Prospects for future studies and observations will also be discussed.