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 21 for “"Clusters of Galaxies"”.
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Distribution of matter in clusters of galaxies
We present observations of the Sunyaev-Zel'dovich effect in 5 clusters of galaxies with a Fourier synthesis telescope - the Australia Telescope. A synthesis telescope has the advantage of simultaneously imaging the discrete radio sources and the Sunyaev-Zel'dovich effect. Observations were made at …
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Distribution of matter in clusters of galaxies
We present observations of the Sunyaev-Zel'dovich effect in 5 clusters of galaxies with a Fourier synthesis telescope - the Australia Telescope. A synthesis telescope has the advantage of simultaneously imaging the discrete radio sources and the Sunyaev-Zel'dovich effect. Observations were made at …
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A study of x-ray substructure in rich clusters of galaxies
A comparison of three tests to determine substructure in rich Abell clusters of galaxies was preformed and the results are presented in this paper. The data used are ROSAT PSPC X-ray images of a sample of 21 clusters drawn from the ACO catalog, and a subset of the ESO Nearby Abell Cluster Survey …
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Cosmology with clusters of galaxies : high-redshift clusters and the evolution of cluster substructure
Clusters of galaxies have become an important cosmological tool, yet we do not un-erstand many aspects of their formation and development. In this thesis, I pursue two projects aimed at using clusters to constrain cosmology and better understanding cluster evolution. First, I examine the Chandra …
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Examining the growth and evolution of magnetic fields in clusters of galaxies: a numerical perspective
… in galaxy cluster atmospheres 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 …
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Mass profiles of clusters of galaxies : a comparison of X-ray and weak lensing observations
Clusters of galaxies are useful probes of cosmology because they are the most massive bound systems and fair representatives of the matter composition of the universe. For clusters to be used as tracers of cosmic evolution, one must determine their masses with high accuracy. In this thesis, we …
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Early Type Galaxies And Reliable Galaxy Cluster Selection
In an era of precision cosmology, clusters of galaxies are the natural consequences under the hierarchical scenario, within which clusters directly encapsulate the history of structure formation. Thus, determining the mass distribution of clusters as a function of redshift enables fundamental tests …
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Dust-Obscured Galaxy Protocluster and Cluster Survey (DOGPACS): Identifying Large-Scale Structures 9−10 Billion Light-Years Away
… time due to gravitational instability to form galaxies and, eventually, large-scale structures, such as clusters of galaxies. Galaxy clusters are the most massive collapsed structures in the universe. During cluster formation, the largest aggregation of gas, galaxies, and dark matter passes …
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Reduction and analysis of Vla maps for 281 radio-loud quasars using the Cray Y-Mp supercomputer
The thesis reports the reduction and analysis of Very Large Array snapshot observations at 6 cm with the A and C arrays of 192 and 192 + 89 radio sources associated with quasars. The sample includes all of the candidates for the complete samples of radio-loud quasars discussed by Wills and Lynds …
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Using the Sunyaev-Zel'dovich effect.
… with the Sunyaev-Zel'dovich (S-Z) effect in clusters of galaxies and its use in cosmology. In Chapter 2, I consider possible causes of error in the determination of H0 from the uncertain geometry of clusters and complications such as lack of virialisation. From numerical simulations, I find …
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Polarization in the Sunyaev-Zeldovich effect
A novel covariant formalism for the treatment of the transfer and Compton scattering of partially polarized light is presented. In this approach, the polarization state of a light beam is described by a tensor constructed from the time average of quadratic products of the electric field components …
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Searching for Extreme-BCG Clusters at 0.2 < z < 1.3
… be responsible for counteracting the formation of the classical “cooling flow”, predicted to be associated with most “cool core” clusters of galaxies. Several studies have shown that many phenomena found in galaxy clusters can be neatly explained by AGN feedback. Yet, the physical mechanism …
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Spatially resolved spectroscopy of faint star-forming galaxies & their environments in the high redshift universe
… is concerned with the spectroscopic observations of distant galaxies, 1 < z < 5. The galaxies presented here are intrinsically faint such that their ux is dominated by ordinary star formation rather than galaxy-galaxy merging and/or strong nuclear activity. Such studies are normally untenable …
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The Influence of Physical Processes in Galaxy Clusters on Observable Cluster Scaling Relations
Clusters of galaxies, which occupy a unique position in hierarchical structure formation, are invaluable cosmological probes and laboratories for astrophysical processes. Cluster scaling relations, which connect their masses and observable properties, provide the link between these two roles. …
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The Galaxy and beyond with the Arcminute Microkelvin Imager
… it was designed specifically for studying galaxy clusters via observations of the Sunyaev-Zel'dovich (SZ) effect, it is also an ideal instrument for Galactic science. This thesis describes science programmes investigating both Galactic objects and galaxy clusters that I have carried out with AMI. …
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The XMM-Newton/SDSS galaxy cluster survey
Galaxy clusters are the largest known gravitationally bound objects, their study is important for both an intrinsic understanding of their systems and an investigation of the large scale structure of the universe. The multi- component nature of galaxy clusters offers multiple observable signals …
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Galaxy groups from observations and simulations
… leading theoretical paradigm for the formation of structure in the Universe. Together with the theory of cosmic inflation, this model makes a clear prediction for the initial conditions for structure formation and predicts that structures grow hierarchically through gravitational instability. As …
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Insights from spectral stacking on the Hi content of cluster galaxies in various environments: a tale of two clusters
… the environment, the stronger the influence. Clusters of galaxies, which are some of the densest known cosmic environments, provide a unique opportunity to study the ongoing environmental processes influencing galaxy evolution. Optical studies have shown that galaxy clusters are typically home …
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