Physical Sciences and Mathematics Commons^™

Axial Symmetry Tests Of Milky Way Disk Stars Probe The Galaxy's Matter Distribution, Austin Hinkel

Theses and Dissertations--Physics and Astronomy

In Galactic dynamics, various assumptions have been employed for mathematical ease. These assumptions are approximately valid, but departures reveal perturbations on our Galaxy. In this dissertation, we select a complete, Gaia DR2 data set, and using this data, we find evidence for axial symmetry breaking in the Galaxy, away from the spiral arms and the Galactic bar. This asymmetry is compatible with a prolate dark matter halo tilted with respect to the disk, with a long axis pointing in the direction of the Magellanic Clouds, and this matches an inventory of nearby torques. These asymmetries vary North and South of …