Department of Physics
WIU Alumnus Dr. Matthew Walker to present on May 1
Apr 11, 2012
Speaker: Dr. Matthew Walker
Date: Tuesday, May 1, 2012
Time: 4:00 pm
Room: 205 Currens Hall
Title: Dark Matter in the Smallest Galaxies
At present the Milky Way's dwarf spheroidal (dSph) satellite galaxie are the smallest objects associated empirically with the phenomenology of dark matter. They also exhibit the largest dynamical
mass-to-light ratios, with some estimates reaching several thousand times the solar value in optical wavelengths. Insofar as their baryons are dynamically negligible, dSphs provide a relatively clear window onto the properties of dark matter within galaxies. I will present empirical constraints, derived from stellar kinematics, on the amount and spatial distribution of dark matter within individual dSphs and will briefly discuss potential implications for cosmology and particle physics.
About the speaker:
Matthew G. Walker graduated from Western Illinois University summa cum laude in 1999 with a double major, concluding a B.S. Degree in Physics and a B.A. Degree in Philosophy. During his time at Western Illinois University, he actively participated in undergraduate research in Dr. Mark S. Boley's magnetoelasticity research laboratory and presented his work at several midwestern conferences, including the Undergraduate Research Symposium at Argonne National Laboratory. His faculty at WIU remember his work as always being thorough, creative, and insightful. After finishing at WIU, Matthew headed off to University of Michigan Ann Arbor, where he concluded his Ph.D. Degree in Astronomy and Astrophysics in May of 2007. (Shortly after this, he actually visited the WIU Physics Department for an invited colloquium on the internal kinematics of dwarf spheroidal galaxies, his dissertation topic.) For the next three years, until 2010, Matthew served as a postdoctoral research associate at the Institute of Astronomy, a part of the University of Cambridge in the UK, where much of his research centered around observational tests of cosmological models, mass measurements, and the search for dark matter. He has been an invited speaker at prestigious physics/astrophysics/astronomy research centers located around the world, in Chile, Germany, France, Sweden, Scotland, and Switzerland, as well as at Oxford, Cambridge, and Princeton. Currently, he holds a prestigious Hubble Fellowship at the Harvard-Smithsonian Center for Astrophysics in Cambridge, MA. It is a pleasure and a privilege for our current faculty and students to have Matthew return for a visit and an invited colloquium within the WIU Physics Department.