We correct the observed Milky Way satellite luminosity function for
luminosity bias and anisotropy using published completeness limits for
the Sloan Digital Sky Survey DR5. Assuming that the spatial
distribution of Milky Way satellites tracks the subhalos found in the
Via Lactea LambdaCDM N-body simulation, we show that there should be
between ~300 and ~600 satellites within 400 kpc of the Sun that are
brighter than the faintest known dwarf galaxies, and that there may be
as many as ~1000, depending on assumptions. By taking into account
completeness limits, we show that the radial distribution of known
Milky Way dwarfs is consistent with our assumption that the full
satellite population tracks that of subhalos. These results alleviate
the primary worries associated with the so-called "Missing Satellites
Problem" in CDM. We show that future, deep wide-field surveys like
SkyMapper, the Dark Energy Survey (DES), PanSTARRS, and the Large
Synoptic Survey Telescope (LSST) will deliver a complete census of
ultra-faint dwarf satellites out to the Milky Way virial radius, offer
new limits on the free-streaming scale of dark matter, and provide
unprecedented constraints on the low-luminosity threshold of galaxy
formation.
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