Contributed Talk - Splinter ISM

Friday, 15 September 2023, 14:40   (H 3006)

Cosmic rays in the interstellar medium: thermodynamics, galactic winds, and observables

Timon Thomas
Leibniz Institute for Astrophysics Potsdam

The evolution of a given galaxy is determined by the physical processes influencing its interstellar medium. Alongside supernova explosions, radiation pressure, and radiative heating, cosmic rays have been identified as a vital feedback agent that is able to regulate star formation and shape the dynamics of the interstellar medium. Both cosmic rays (CRs) and the interstellar medium are tightly connected. Next to providing an additional pressure component counteracting gravity, CRs (partly) ionize and heat neutral regions of the interstellar medium even if other heating mechanisms or ionizing UV radiation are absent. On the other hand, the chemical composition and the magnetic field topology of the interstellar medium directly influence how CRs are transported along magnetic field lines. In my talk, I introduce the CRISP (Cosmic Ray and InterStellar Physics) simulation framework which was designed to investigate the aforementioned processes and to gain insight into their combined dynamics and their influence on galaxy evolution. I present the first simulations of idealized Milky Way-type galaxies performed using the CRISP framework. I focus my presentation on three points: 1) how CRs and radiation impact the thermodynamics of the ISM 2) how they are working in unison with supernovae to drive highly structured and turbulent galactic winds 3) how we can model infrared dust and nebular-line emission in order to compare simulations with observations.