• Corpus ID: 116616872

The Environment Of Galaxies And Groups Of Galaxies

  title={The Environment Of Galaxies And Groups Of Galaxies},
  author={Owain N. Snaith},
In this thesis, we employ two numerical tools - semi- analytical models and N-body plus hydrodynamical simulations of large scale structure and individual galaxies - to explore the underlying physics governing the formation and evolution of groups of galaxies, and the role of environment in generating polar structures around disk galaxies. Using phenomenological models of baryonic physics imposed upon large-scale dissipationless simulations of the Universe, semi-analytic models (SAMs) are… 
Machine learning in galaxy groups detection
A probabilistic model capable of detecting galaxy groups and clusters based on the Hough transform based on adaptive local kernel (PHTALK), which has the main advantage of its flexibility to incorporate any prior knowledge expressed in terms of a galaxy group model.


The colours of satellite galaxies in groups and clusters
Current models of galaxy formation predict satellite galaxies in groups and clusters that are redder than observed. We investigate the effect on the colours of satellite galaxies produced by the
The mass assembly of galaxy groups and the evolution of the magnitude gap
We investigate the assembly of groups and clusters of galaxies using the Millennium dark matter simulation and the associated Millennium gas simulations, and semi-analytic catalogues of galaxies. In
Satellite galaxies and fossil groups in the Millennium Simulation
We use a semianalytic galaxy catalogue constructed from the Millennium Simulation(MS) to study the satellites of isolated galaxies in theCDM cosmogony. The large volume surveyed by the MS (500 3 h 3
Merger rates in hierarchical models of galaxy formation
We present an analytical description of the merging of virialized haloes which is applicable to any hierarchical model in which structure grows via gravitational instability. The formulae are an
The kinematics of dense clusters of galaxies. 3: Comparison with cosmological models
We compare the combined distribution of 31 group and 25 cluster velocity dispersions with the ensemble of 32 models for the formation and evolution of large-scale structure examined by Weinberg &
Compact groups in theory and practice – I. The spatial properties of compact groups
We use a mock galaxy catalogue based on the Millennium Run simulation to investigate the intrinsic spatial properties of compact groups of galaxies. We find that approximately 30 per cent of galaxy
How filaments of galaxies are woven into the cosmic web
LARGE-SCALE structure in the distribution of galaxies is thought to have evolved through gravitational instabilities from small density fluctuations in the (largely homogeneous) early Universe. This
A comparison of galaxy merger history observations and predictions from semi-analytic models
Mergers are predicted in all cosmological models involving cold dark matter (CDM) to be one of the dominant channels whereby galaxies accrete mass. In this paper, we present a detailed analysis of
The visible environment of polar ring galaxies.
A statistical study of the environment around Polar Ring Galaxies is presented. Two kinds of search are performed: 1) a study of the concentration and diameters of all the objects surrounding the
Ram pressure stripping the hot gaseous haloes of galaxies in groups and clusters
We use a large suite of carefully controlled full hydrodynamic simulations to study the ram pressure stripping of the hot gaseous haloes of galaxies as they fall into massive groups and clusters. The