Multiphase gas in jellyfish galaxies

• Applicant: Professor Dr. Christoph Pfrommer
• Subject Area: Astrophysics and Astronomy
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 567737545

Jellyfish galaxies are observed to exhibit long, dense tails extending up to 100 kpc into the intracluster medium (ICM), which result from a ram-pressure interaction of the galactic disk and its environment with the hot gaseous wind the galaxy experiences as it orbits within a galaxy cluster. These jellyfish tails are observed to be star-forming and magnetized, which raises the question how cooling and star formation can proceed in such a highly turbulent environment that is embedded in a hot ICM of several tens of million degrees. To answer this question we propose to use the Arepo code to perform magnetohydrodynamical windtunnel simulations of a jellyfish galaxy experiencing ram-pressure stripping by interacting with an ICM wind. In our simulations, the ICM density, temperature and velocity that the galaxy encounters are time-dependent and comparable to what a real jellyfish galaxy experiences while orbiting within the galaxy cluster. In particular we will be using our new CRISP (Cosmic Ray and InterStellar Physics) framework to model the multiphase interstellar medium (ISM) and account for ultraviolet radiation from massive stars, supernova explosions, and cosmic rays, which mutually influence the dynamics of the ISM. We propose to run a series of high-resolution windtunnel simulations of galaxies to study 1.) the impact of modeling a multiphase ISM on ram-pressure stripping and the formation and morphology of jellyfish tails, 2.) the conditions leading to star formation in the jellyfish tails, and 3.) the effect of varying the galactic inclination and the galaxy's orbit on ram-pressure stripping, the emergent jellyfish tails and star formation.

• DFG Programme: Research Grants