| Abstract: |
Galaxy dynamics play a key role in understanding the formation and evolution of galaxies, as well as in constraining the nature of dark matter (DM). In this talk I will summarize recent results from the SPARC (Spitzer Photometry and Accurate Rotation Curves) project. To date SPARC is the largest collection of disk galaxies (spirals and dwarf irregulars) at z=0 with both near-infrared surface photometry, probing the stellar mass distribution, and extended HI rotation curves, probing the gravitational potential out to large radii. I will discuss three main empirical laws for rotationally supported galaxies: the baryonic Tully-Fisher relation, the central surface density relation, and the radial acceleration relation. These empirical laws are remarkably tight by astronomical standards and point to a close coupling between visible baryons and observed dynamics, even in the DM-dominated, low-acceleration regime. I will discuss the implications of these empirical laws for LCDM models of galaxy formation as well as for alternative theories such as Milgromian Dynamics (MOND). |
