University of Minnesota
School of Physics & Astronomy

Physics and Astronomy Calendar

Friday, September 26th 2014
Speaker: Dr. Marc Seigar, UMD
Subject: New Approaches for Determining the Dark Matter Content in Spiral Galaxies

Our standard cosmological model, LCDM (Lambda Cold Dark Matter),
reproduces the large scale structure of the Universe extremely well. However, on smaller, galaxy-sized scales, there are several issues. One of these is the so-called cusp-core problems, where LCDM predicts cuspy central density profiles on for dark matter halos of all mass scales. However, observational studies show that dwarf galaxies have lower than predicted densities and tend to have constant density cores. Another problem with LCDM is the Tully-Fisher zeropoint problem, which refers to the fact that standard models cannot reproduce the observed relation between galaxy luminosity and circular velocity (the Tully-Fisher relation) without over-producing the number density of galaxies at fixed luminosity. In this presentation, I will describe new methods we are pursuing to determine dark matter density profiles in galaxies, with a
view to coming to a solution to the above issues.

The weekly calendar is also available via subscription to the physics-announce mailing list, and by RSS feed.