Understanding the Formation of Ultra-Diffuse Galaxies (UDGs) through their Stellar Kinematics

This thesis studies large, low surface brightness "Ultra-Diffuse Galaxies" using the Keck telescopes on Mauna Kea. The thesis had to develop new tools for the analysis of low signal to noise data in order to study these galaxies. These tools have been made publicly available. Scientifically, it sought to understand how such puzzling galaxies form by weighing them using the motions of their stars (their stellar kinematics). It provides measurements for the basic structure of these galaxies and describes how they are difficult to understand in our current galaxy formation theories.