The Evolution of Protoplanetary Disks at Millimeter Wavelengths

Jonathan Williams

Its becoming more and more evident from exoplanet surveys that the end
state of a typical circumstellar disk is a planetary system.  This gives
an imperative to learn about the properties of all disks, not just the
bright ones!
We are at the cusp of being able to make comprehensive millimeter
wavelength surveys of young protoplanetary disks in nearby star forming
regions and learn about the evolution of the gas and dust content and
the grain size distribution.  I will discuss what continuum surveys
have told us to date about the initial disk mass distribution, its rapid
evolution, and the effect of external photoevaporation.  I will also
show new results from a CO isotopologue line survey in Taurus that
informs us of the gas content and gas-to-dust ratio.  Ultimately, these
can be considered pathfinder experiments for ALMA which will provide unbiased
disk surveys at millimeter wavelengths over a much larger range of ages
and make possible direct statistical links between disk evolution
and planetary architectures.