Puzzles in Galaxy Scaling Relations

Stephane Courteau (Queens University)

Galaxies can be described in terms of their structure, dynamics and stellar populations. Some very robust correlations between various galaxy structural properties, such as total luminosity, maximum circular velocity, and size have been known for many decades yet still lack a theoretical explanation! A fundamental challenge to understanding these scaling relations, and ultimately galaxy formation and evolution, is the elusive interplay between visible and dark matter. I will discuss the latest derivations of galaxy scaling relations and our attempts to understand them.