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Giant galaxies and their globular cluster populations: Analysis and results from a wide-field imaging survey and archive

Posted on:2017-01-28Degree:Ph.DType:Dissertation
University:Indiana UniversityCandidate:Young, Michael DFull Text:PDF
GTID:1460390014474188Subject:Astronomy
Abstract/Summary:PDF Full Text Request
The globular cluster (GC) systems of giant galaxies are valuable and intriguing tools for a number of reasons, both in terms of the properties of the overall system as well as the properties of the individual GCs that make up the system. GCs are old: their ages range from a few Gyrs up to ~12 Gyrs, and they apparently form during galaxy mergers and major star formation events. The ensemble properties (including the color, metallicity, and spatial distributions) of the GC system constrain theoretical models of galaxy formation. For several years we have been carrying out a wide-field imaging survey of the GC populations of a sample of giant spiral, S0, and elliptical galaxies with distances of ~ 10 - 30 Mpc. In this dissertation I present results and analysis of the GC systems of eight giant galaxies, representing a significant addition to the survey dataset. I also describe how the survey data and metadata was collected, homogenized, and ingested into a custom database and archive, and how a web portal was created to disseminate the survey products to the wider scientific community. I have developed and tested a probability factor to quantify the likelihood that a given GC candidate is in actuality a GC. I explored enhanced statistical methods to detect subpopulations in GC systems, and found that six of the GC systems in our survey presented with three GC subpopulations. I explored how the spatial and azimuthal distributions of these subpopulations differ in each host galaxy. I have supplemented our survey results with select GC system studies from the literature, and tested how different host galaxy properties correlate with the total number of globular clusters in a given system, finding that the combination of the dynamical mass of the galaxy and the K-band luminosity of the galaxy offered the best correlation with the number of GCs. Lastly, I applied this combination of predictors to a published catalog of GC system studies and found that the predictions were in good agreement with existing observations.
Keywords/Search Tags:Giant galaxies, GC system, Survey, Globular, Results
PDF Full Text Request
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