Graduation Year


Document Type

Open Access Senior Thesis

Degree Name

Bachelor of Science


Physics & Astronomy

Reader 1

Philip Choi

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Rights Information

© 2008 Kristen Petrillo


This paper examined a few different types of interacting galaxies and the implications the data has on cosmological theories. An analysis of the Holmberg Effect, Holmberg (1969)’s observation that companion galaxies tend to be near the poles of edge-on galaxies rather than in the planes, was done by reexamining the spirals viewed by Holmberg. Only using radial velocity confirmed companions to test for this effect showed that if anything, the opposite of the Holmberg effect is true. However, due to small number statistics, more edge-on spirals and their companions would have to be viewed in order to determine if this is an actual physical effect of anisotropic companion distribution around primary galaxies. It is important to discover if there is a preferred distribution, because it could point to the distribution of dark matter around the primary galaxies, and have interesting impacts on large-scale universal structure and cosmology theory.


Previously linked to as:,47

OCLC number: 549439184