The Impact of realistic galaxy orbits on jellyfish galaxy properties
type: CreativeWork
description: Galaxy clusters, the most massive dark matter halos in the universe, decisively influence their environment and the evolution of galaxies within them. As galaxies move supersonically through the hot, magnetized intracluster medium (ICM) filling the space between galaxies in galaxy clusters, ram pressure stripping (RPS) can remove large fractions of the interstellar and circumgalactic gas of galaxies. This process creates jellyfish galaxies with tails extending up to 100 kpc, and transforms star-forming spirals into quenched galaxies. The multiphase, magnetized and star-forming tails of jellyfish galaxies also serve as unique astrophysical laboratories. Cosmological simulations can model RPS, but their resolution is often too low to capture the detailed physics of jellyfish galaxies. Alternatively, windtunnel simulations, which expose galaxies in their rest frames to a wind that resembles the ICM, allow for a higher resolution but typically rely on idealized wind conditions. In this thesis, I present eight high-resolution windtunnel simulations of RPS for 1e12 M☉ galaxies. I build on the setup from Sparre et al. (2024a) and incorporate realistic ICM-winds derived from galaxy orbits in the cosmological zoom-in simulations PICO-Clusters. I validate the initial conditions using PICO-Clusters, explore simulating the impact of dark matter via a static potential, and optimize the simulation mesh to reduce computational costs. My simulations reveal fragmented jellyfish tails with fountain flows and aligned magnetic fields. The properties of these tails and the efficiency of stripping vary depending on whether galaxies already experience significant ram pressure outside the cluster's virial radius or only after a period of falling in to galaxy clusters, together with material that is accreted onto these clusters and shocked near the cluster's virial radius.
abstract: Galaxy clusters, the most massive dark matter halos in the universe, decisively influence their environment and the evolution of galaxies within them. As galaxies move supersonically through the hot, magnetized intracluster medium (ICM) filling the space between galaxies in galaxy clusters, ram pressure stripping (RPS) can remove large fractions of the interstellar and circumgalactic gas of galaxies. This process creates jellyfish galaxies with tails extending up to 100 kpc, and transforms star-forming spirals into quenched galaxies. The multiphase, magnetized and star-forming tails of jellyfish galaxies also serve as unique astrophysical laboratories. Cosmological simulations can model RPS, but their resolution is often too low to capture the detailed physics of jellyfish galaxies. Alternatively, windtunnel simulations, which expose galaxies in their rest frames to a wind that resembles the ICM, allow for a higher resolution but typically rely on idealized wind conditions. In this thesis, I present eight high-resolution windtunnel simulations of RPS for 1e12 M☉ galaxies. I build on the setup from Sparre et al. (2024a) and incorporate realistic ICM-winds derived from galaxy orbits in the cosmological zoom-in simulations PICO-Clusters. I validate the initial conditions using PICO-Clusters, explore simulating the impact of dark matter via a static potential, and optimize the simulation mesh to reduce computational costs. My simulations reveal fragmented jellyfish tails with fountain flows and aligned magnetic fields. The properties of these tails and the efficiency of stripping vary depending on whether galaxies already experience significant ram pressure outside the cluster's virial radius or only after a period of falling in to galaxy clusters, together with material that is accreted onto these clusters and shocked near the cluster's virial radius.
author: Dusch, Niklas
keywords: galaxies, jellyfish galaxy, galaxy clusters, magnetohydrodynamics, simulations, Galaxien, Quallengalaxie, Galaxienhaufen, Magnetohydrodynamik, Simulationen
date published: 2025-10-24
date modified: 2026-07-24T03:52:15Z
provider: Universität Potsdam - Thes
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Universität Potsdam