Shedding Light on the Dark: Exploring the Relation Between Galaxy Cluster Mass and Temperature Through Weak Gravitational Lensing

[摘要] The evolution of the abundance of galaxy clusters is a powerful tool for quantifying the presence of dark energy in the universe.To use this tool, it is necessary to measure precise cluster masses.As masses are difficult to measure directly, this often requires understanding the scaling relation between mass and one of several observables.In this dissertation we work with optical data from the Dark Energy Survey;;s Science Verification (DES-SV) run and X-ray data from the XMM Cluster Survey to examine the scaling relation between cluster mass and X-ray temperature.As our mass measurements are derived using weak gravitational lensing, the first component of this thesis describes the measurement of galaxy shapes, a necessary step in lensing studies.In the process of gathering data to cover our entire cluster sample, we measure ellipticities of approximately 590,000 galaxies, and make this additional data public to complement the official DES-SV shape catalog.The second component of the dissertation describes our measurement of stacked weak lensing masses of 133 clusters.As SV data quality varies over different parts of the sky, we develop a method for modeling observations that accounts for inhomogeneous data quality.This method makes it possible to incorporate clusters with partial data into lensing analyses.In the final section, we constrain the galaxy cluster mass-temperature scaling law, and find it to be consistent with the self-similar model and with previous measurements in the literature.We also examine the effect on the scaling relation of several variations on the data.

[发布机构] University of Michigan

[效力级别] galaxy clusters

[关键词] cosmology;galaxy clusters;weak lensing;X-ray measurements of clusters;cluster mass-temperature scaling relation;Dark Energy Survey;Astronomy;Physics;Science;Physics