Contributed Talk - Splinter ISM

Friday, 15 September 2023, 14:20   (H 3006)

A multi-frequency view on simulating galaxy formation with cosmic rays

Maria Werhahn
Max Planck Institute for Astrophysics (MPA)

Cosmic rays (CRs) are ubiquitous in the interstellar medium (ISM) of the Milky Way and nearby galaxies and are thought to play an essential role in governing their evolution. However, many of their properties are not well-constrained. Since direct measurements of CRs are limited to our local environment, observations of radio and gamma-ray emission arising from CRs provide a powerful tool to constrain their transport properties and interactions with the ISM and magnetic fields in other galaxies. To help better understand the link between observational signatures and CR physics, we use a series of magneto-hydrodynamical AREPO simulations of isolated galaxies including self-consistent CR physics, with subsequent modelling of the CR spectra and their multi-frequency emission. I will show the underlying processes that are required to simultaneously match the observed correlations and spectra of star-forming galaxies like M82 and NGC 253 both in the radio and gamma-ray regime. Furthermore, I demonstrate the importance of modelling spectrally resolved CR transport for an accurate prediction of spatially resolved high-energy gamma-ray emission, as will be probed by the upcoming Cherenkov Telescope Array observatory.