of the material in the universe is invisible. That is one of the most
dramatic, perplexing, and yet persistent findings of modern
astrophysics. We know that dark matter exists because of the way it
tugs on galaxies, heats cosmic gas, and bends the light
from distant objects. My research involves mapping the large
dark halos within cluster of galaxies, looking for structures
that reveal the nature and composition of dark
I am co-director of the SFSTAR astrophysical computing facility. I have authored the Joint Analysis of Cluster Observations (JACO) package for modeling galaxy clusters; and the Hrothgar MCMC model fitting toolkit, which has been used to tackle a diverse array of problems across physics and astronomy.