#RAM PRESSURE STRIPPING GALAXIES CODE#

To reproduce the numerical results we propose a fitting formula depending on the disk tilt angle and on the column density of the encountered ICM. In some galaxies ram-pressure stripping has done serious damage to the H I disks, while in other galaxies turbulent viscous stripping and thermal conductivity have caused a mild, but global H I. This behavior can also be found in previous simulations. Although various hydrodynamical effects are present in the ISM-ICM interaction, the main quantitative stripping results appear to be roughly consistent with a simple scenario of momentum transfer from the encountered ICM. The dependence on the disk tilt angle is more pronounced for compact ICM distributions, however it almost vanishes for strong ram pressure pulses. Results: The simulations confirm the general trend of less stripping at orientations close to edge-on. These SPH calculations extend the set of existing results obtained from different codes using various numerical techniques.

#RAM PRESSURE STRIPPING GALAXIES CODE#

Methods: A grid of numerical simulations with varying parameters is produced using the tree/SPH code GADGET with a modified method for calculating the ISM-ICM interaction. To isolate the effect of inclination, galaxies on strictly radial orbits are considered. We further study how results of numerical simulations could be estimated analytically. Previous numerical simulations based on various approaches suggested that, except for near edge-on disk orientations, the amount of stripping depends very little on the inclination angle.ДЄims: Following our previous numerical and analytical study of face-on stripping, we extend the set of parameters with the disk tilt angle and explore in detail the effects of the ram pressure on the interstellar content (ISM) of tilted galaxies that orbit in various environments of clusters, with compact or extended distributions of the intra-cluster medium (ICM). But also the gas disks of galaxies in low density environments (cluster outskirts or groups) are disturbed by the ICM-flow and back-falling material, so that they should also be pre-processed.Context: Ram pressure stripping of galaxies in clusters can yield gas deficient disks. From our simulations we conclude that gas disks of galaxies in high density environments (like cluster centres) are heavily truncated or even completely stripped. 1 INTRODUCTION Galaxies are vastcollections of gravitationally bound stars and gas, situated inside haloes of dark matter (DM). Key words: galaxies: evolutiongalaxies: fundamental parametersgalaxies: ISM galaxies: photometryradio lines: galaxies. The numerical results for the stripping efficiency are in good agreement with analytical estimates. such as ram-pressure stripping of cold gas to explain this. For a fixed galactic gas surface density the stripping efficiency does not depend on the vertical structure and thickness of the gas disk. The stripping efficiency depends slightly on the Mach number of the ICM flow, however, the main parameter is the ram pressure. We find that RPS proceeds in three phases: firstly the instantaneous stripping phase, secondly the dynamic intermediate phase, and thirdly the quasi-stable continuous viscous stripping phase. Some of the interstellar gases stripped off the disk plane may be accreted later if they do not reach the escape velocity (Vollmer et al. This enables us to use high resolution and to compile a comprehensive parameter study that varies galaxy properties as well as ICM conditions. The simulations in this work are restricted to the face-on case, which allows us to use a 2D code. The aim of this work is to study the process of RPS of disk galaxies with hydrodynamical simulations. The gas is the raw material for star formation, therefore such ram pressure stripping (RPS) has severe consequences for a galaxy. The basic idea for the latter is that a galaxy is stripped of its gas by ram pressure as it moves through the ICM.

On the one hand there are (gravitational) interactions among the galaxies themselves, on the other hand there is the interaction between the galaxies and the ICM. Theoretical work has proposed several mechanisms that can be at work in clusters and groups. Comparative observations of galaxies, especially disk galaxies, in various environments reveal systematic differences in morphology, colour, star formation activity and gas contents. In addition to galaxies, clusters and groups are filled with a hot tenuous gas, the intracluster medium or intragroup medium (abbreviated ICM for both). Galaxies exist in various environments, ranging from isolated field galaxies over galaxy groups to clusters. Ram pressure is modeled as an additional acceleration on the clouds located at the surface of the gas distribution in the direction of the galaxys motion within the cluster.

Ram pressure stripping galaxies