Intricacies of searching for supernova remnants at (very) high energies off the Galactic plane

Supernova remnants (SNRs) have traditionally been considered prime candidates for the acceleration of particles to high energies and to thus significantly contribute to the Galactic cosmic ray (CR) density. Most of them are first seen at radio wavelengths, around 10% are subsequently also detected at γ-ray energies. Current-generation radio surveys, such as the EMU survey with ASKAP, are revealing an increasing number of low-surface-brightness radio SNRs at high Galactic latitudes. We are searching for high-energy counterparts, which can provide important insights into understanding cosmic ray physics and constraining theories of CR acceleration and escape. These objects expanding in low-density media probe unperturbed environments that complement the population of (very-)high-energy-emitting SNRs in the Galactic plane.