MilkyWay@home: Harnessing volunteer computers to constrain dark matter
  in the Milky Way
  MilkyWay@home is a volunteer computing project that allows people from every
country in the world to volunteer their otherwise idle processors to Milky Way
research. Currently, more than 25,000 people (150,000 since November 9, 2007)
contribute about half a PetaFLOPS of computing power to our project. We
currently run two types of applications: one application fits the spatial
density profile of tidal streams using statistical photometric parallax, and
the other application finds the N-body simulation parameters that produce tidal
streams that best match the measured density profile of known tidal streams.
The stream fitting application is well developed and is producing published
results. The Sagittarius dwarf leading tidal tail has been fit, and the
algorithm is currently running on the trailing tidal tail and bifurcated
pieces. We will soon have a self-consistent model for the density of the smooth
component of the stellar halo and the largest tidal streams. The $N$-body
application has been implemented for fitting dwarf galaxy progenitor properties
only, and is in the testing stages. We use an Earth-Mover Distance method to
measure goodness-of-fit for density of stars along the tidal stream. We will
add additional spatial dimensions as well as kinematic measures in a piecemeal
fashion, with the eventual goal of fitting the orbit and parameters of the
Milky Way potential (and thus the density distribution of dark matter) using
multiple tidal streams.
