Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 35 for “"Cosmological Simulations"”.
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Cosmological Simulations of Galactic Disc Assembly
… heating in disc galaxies by analysing a suite of cosmological Milky Way-type disc simulations run with different particle-and grid-based hydrodynamical codes and different resolution, and compare them with observations of the Milky Way. By studying the kinematics of disc stars in these …
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Nonlinear Growth of Structure in Cosmological Simulations
… cover the range of numerical algorithms used in cosmological N-body simulations. For the mass function, the matter power spectrum, and halo profiles --- the most important statistics for this thesis --- codes agree at less then 10% over wide dynamic ranges. This robustness gives us additional …
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Exploring Galaxy Clusters and Groups with Cosmological Simulations
… Environments}$ (FABLE) project, a new suite of cosmological hydrodynamical simulations of galaxies, groups and clusters designed to further our understanding of the formation and evolution of these fascinating objects. Firstly I perform a detailed comparison of the FABLE simulations to …
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Probing local group galactic substructure with cosmological simulations
… of a series of studies using dark matter only cosmological N-body simulations of MW-mass galaxies to address topics related to these issues. In light of the recent Planck mission, I investigate how changes to cosmological parameters affect dark matter halo substructure. I find that the process …
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The Structure of Dark Matter Haloes in Cosmological Simulations
… dark matter haloes using very large dark matter simulations, and use smaller, higher-resolution simulations to investigate how the distributions of these properties are changed by the physical processes associated with baryons and galaxy formation. We begin with a brief review of the necessary …
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Cosmological Simulations with Resolved Supermassive Black Hole Binary Dynamics and Accretion
… and supermassive black hole (SMBH) binaries in cosmological zoom-in simulations. The focus of the study is twofold: first, the agreement between simulated galaxies and observed scaling relations is assessed, followed by an analysis of the impact of different mass accretion models on SMBH …
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On the evolution of gaseous haloes in cosmological simulations of galaxy formation
… as well as by the larger-scale environment. Simulations that realistically model this gas are therefore crucial to interpreting this new data, and ultimately helping us understand how galaxies assemble. However, many cosmological simulations sacrifice resolution in gaseous haloes to reduce …
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Decoding Dark Matter Halos through the Lens of Machine Learning
… understood, especially at galactic scales. While cosmological simulations and astrophysical surveys have made significant strides in constraining DM properties, upcoming surveys will generate terabytes of complex, high-dimensional data. It is thus imperative to develop new methodologies capable of …
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From Spitzer mid-infrared observations and measurements of peculiar velocities to constrained simulations of the local universe
… formation and galaxy evolution rely on numerical cosmological simulations. Still, only one universe observable from a given position, in time and space, is available for comparisons with simulations. The related cosmic variance affects our ability to interpret the results. Simulations constrained …
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Examining the growth and evolution of magnetic fields in clusters of galaxies: a numerical perspective
… and have a variety of astrophysical and cosmological consequences. Magnetic fields can contribute to the pressure support of clusters, affect thermal conduction, and modify the evolution of bubbles driven by active galactic nuclei. However, we currently do not fully understand the origin …
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Stellar Spiral Structures in Realistic Dark Matter Haloes
… dark matter haloes with very high resolution simulations. I first study the impact of the shape of the dark matter haloes. I find that non-adiabatic changes to the dark matter halo shape, commonly found in cosmological simulations due to the assembly history of haloes, can trigger strong …
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Understanding the Milky Way with Stars
… models for dark matter. At the same time, cosmological simulations and machine learning techniques offer a bridge between the theory and observations. In this thesis, I combine observation of stellar kinematics and chemistry with cosmological simulations to understand the formation and …
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Fast galactic structure finding using graphics processing units
Cosmological simulations are used by astronomers to investigate large scale structure formation and galaxy evolution. Structure finding, that is, the discovery of gravitationally-bound objects such as dark matter halos, is a crucial step in many such simulations. During recent years, advancing …
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Quenching of Star Formation in the Local Universe A Comparison of Hydrodynamical Simulations with Spectroscopic Observations
… feedback quenching from three state-of-the-art cosmological simulations: EAGLE, Illustris and IllustrisTNG. Our machine learning (ML) classification reveals supermassive black hole mass (MBH) as the most predictive parameter in determining whether a galaxy is star forming or quenched at redshift …
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Machine learning applications in astrophysics: Reduced-order modelling for chemical kinetics and galaxy merger reconstruction with graph neural network
… integration of customized chemistry in simulations. The combination of neural ordinary differential equations and autoencoders is shown to be a promising approach for reducing the complexity of chemical kinetics simulations. Specifically, autoencoders identify the reduced reaction …
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Measuring Galaxy Asymmetry in Different Dimensions
… We create a sample of mock cubes using the SIMBA cosmological simulation using SKA pathfinder observational parameters of the MeerKAT radio-telescope and WALLABY survey. The asymmetries of the sample are computed and we find little correlation between 2D and 1D asymmetries. We also find a strong …
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Formation and dynamics of the Galactic disc and halo
… and destroy substructure. By using tailored and cosmological simulations, this substructure can be modelled and interpreted to learn about the formation and past evolution of the Milky Way. A detailed understanding of our own Galaxy's assembly also provides a test for the cosmological models …
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The Kinematical Parameters of Minor Mergers and their Observational Traces
… we call a ``minor merger''. First, we derived in cosmological simulations the kinematical properties of dark matter halos that are minor merging and their abundance in space and time. We found that minor merger were most likely at a time 7Gyrs ago and happened typically once for a Milky Way sized …
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The Impact of realistic galaxy orbits on jellyfish galaxy properties
… 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, …
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Metallicity correlations in galaxies
… current integrated field unit observations and simulations, this thesis tries to gradually investigate the following aspects. I show that two-point correlations of current observed metallicity maps can be described by a simple model that considers only stochastic metal injection and diffusion. …
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