Electronic Thesis and Dissertation Repository


Doctor of Philosophy




Dr. S. C. Gallagher


In this thesis, I have explored the star cluster populations of several compact groups of galaxies, based on observations with the Advanced Camera for Surveys and the Wide Field Camera 3 on the Hubble Space Telescope. Low velocity dispersions and high galaxy number densities, the conditions of compact groups (in particular Hickson Compact Groups), represent an environment with frequent and prolonged interactions. Such environment can trigger the formation of star cluster populations associated with specific events. The BVI study has shown that star clusters can be used as a powerful tool for studying such events triggered by mergers and tidal interactions between galaxies. The study compares the basic properties between cluster populations in compact groups at distinct evolutionary stages. The information on star clusters in compact groups of galaxies that has been presented in a number of papers is consolidated and presented it in a single catalogue, with the goal of further assisting researchers in star cluster-related studies.

For my next study I concentrate on one of the compact groups, HCG 92, also known as Stephan’s Quintet. To the initial BVI observations I add observations in U336 and V547 filters, with the Wide Field Camera 3 on the Hubble Space Telescope. The addition of these filters, specifically U336 , breaks the age-extinction degeneracy of the BVI photometry and allows to shift from a qualitative description of cluster ages to a more quantitative analysis, along with determinations of intrinsic reddening and masses.

BVI_catalogue.dat (1202 kB)
Full BVI catalogue of star clusters in five Hickson compact groups

UBVmVI_catalogue.dat (1845 kB)
Full UBVmVI catalogue of star clusters in Stephan’s Quintet