Speaker
Description
Cosmic rays (CRs), with their substantial energy density, play a key role in the evolution of galaxies, and in shaping their interstellar mediums (ISM). Accelerated in supernova (SN) shocks, CRs propagate along magnetic field lines, distributing energy and momentum throughout the galaxy. This process ionizes and heats the gas and drives large galactic outflows by creating pressure gradients, all of which help regulate and suppress star formation. Observationally, the influence of CRs is revealed via the emission of gamma radiation.
We perform high-resolution magnetohydrodynamical simulations of Milky-Way-like galaxies, in which we follow individual massive stars and include self-consistent stellar feedback such as SNe and CRs, dynamically coupled to the MHD equations. We model the multi-phase interstellar medium using a non-equilibrium chemical network that includes hydrogen and carbon species, allowing us to take into account the relevant cooling and heating processes and compare the simulations to observations.
In this work, we present the effects of thermal and CR feedback on the galactic structure and gas dynamics across different ISM phases. We find that CRs convert fountain flows into sustained galactic outflows - absent in the MHD-counterparts - driving mass loss from the entire disk. We analyze these outflows in terms of energy loading and their impact on vertical structure. Additionally, we back up our simulations with post-processed, multi-wavelength gamma-ray emission from both CR protons and electrons, and provide a direct comparison to observational features in the Milky Way.
