Early Type Galaxies And Reliable Galaxy Cluster Selection

Galaxy Clusters;Cosmology;Large scale structure

Song, Jeeseon

关键词: Galaxy Clusters;    Cosmology;    Large scale structure;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/18515/Song_Jeeseon.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

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 of this structure formation process.My projects have initially been motivated by an intellectual inquiry into how we can effectively and accurately analyze data from large cluster surveys, such as the South Pole Telescope (SPT), the Blanco Cosmology Survey (BCS) and the upcoming Dark Energy Survey (DES), which now extends to the galaxy formation and evolution studies.Through this thesis project followed by immediate extension of the thesis, I, therefore, aim to achieve three distinct, but highly inter-related main research goals: (1) creating mock catalogs that represent the universe well enough, (2) employing these mock catalogs to quantitatively characterize optical selection tools and then applying those well understood selection tools to large new surveys, and (3) exploring the underlying physics of galaxy population and property evolution over the cosmic time.Clusters of galaxies are an important laboratory for exploring galaxy formation and evolution.Automatic data analysis tools, such as cluster finding algorithms or mass and photometric redshift estimators, need to be tested prior to their use.We have launched a project to create realistic mock galaxy catalogs that will perform these tests accurately.This thesis project also includes development of tools to characterize clusters of galaxies, such as a red-sequence redshift estimator and an optical richness estimator.We also explore one of the candidates of contamination in cluster finding in sub-mm wavelength.The scientific goals to have been achieved are to build a realistic mock catalog on which several analysis tools are tested to better understand our ability to make accurate measurements; to develop an independent redshift and optical richness estimators with their applications to real clusters and to understand their systematics better to reduce the scatter; and to address a cautionary point in sub-mm cluster finding due to radio galaxies that are associated with clusters.These projects, in conjunction with each other, are demonstrated as crucial elements in constraining cosmological parameters to understand the evolution of the universe.