Tea and cookies will be available 3:45PM - 4:15 PM, and the talk will begin at 4:15 PM.
It may be possible to have dinner with the speaker; if interested, please contact Michael Richmond.
Abstract: I will discuss efforts to use the motions of stars to learn about the nature of particles. More specifically, I will translate stellar kinematics observed in the nearest, smallest and and 'darkest' galaxies into a test of the standard hypothesis that dark matter consists of 'cold' and 'collisionless' (i.e., weakly interacting) particles. This model now seems to require that baryon-driven processes (e.g., energetic feedback from supernova explosions) alters the internal structure of galactic dark matter halos systematically with respect to predictions derived from dissipationless cosmological simulations. I will discuss future work that will let us judge whether such reconciliation is energetically feasible or whether the dark matter model requires more complexity.
Bio: I study the astrophysical properties of dark matter, thus far via optical imaging, spectroscopy and dynamical modelling of the 'dwarf' galaxies that surround the Milky Way and neighboring Andromeda. The dwarf galaxies include the oldest, smallest and 'darkest' (i.e., composed almost entirely of dark matter) galaxies known, and currently represent the smallest physical scales (sizes of ~ 100 light years, speeds of a few kilometers per second, masses of ~100,000 Suns) that are associated empirically with dark matter.
RIT AST Colloquia: Please visit the AST Colloquium Schedule for a full list of RIT & UofR Colloquia.
|2/3/2014||Kristine Spekkens||"A Model-Based Approach for Measuring Disk Galaxy Structure"||76-1275|
|3/3/2014||Leslie Hebb||"Mapping small and large-scale magnetic features on low mass stars"||76-1275|
|3/10/2014||Matthew Walker||"Galactic Dynamics and the Nature of Dark Matter"||76-1275|
|3/24/2014||David Wilner||A New "Radio Era" for the Study of Planet-Forming Disks||76-1275|
Fall 2013 RIT AST Colloquia
|Date||Speaker||Title of Talk|
|12-2-2013||Jonathan Levine||Dating Extraterrestrials|
|11-22-2013||Chat Hull||Polarization science with CARMA|
|11-18-2013||Eric Gawiser||Probing Cosmology with Distant Galaxies in the Era of Big Data|
|11-4-2013||Ester Aliu||Astrophysics at the TeV Scale|
|10-21-2013||Eric Huff||How to get more out of your lensing signal|
|9-30-2013||George Privon||Dynamical Models of Galaxy Mergers: Connecting Simulations and Data|
|9-13-2013||Dan Batcheldor||Extreme Contrast Ratio Astronomy|