  In this analysis we illustrate how the relatively new emission mechanism
known as spinning dust can be used to characterize dust grains in the
interstellar medium. We demonstrate this by using spinning dust emission
observations to constrain the abundance of very small dust grains (a $\lesssim$
10nm) in a sample of Galactic cold cores. Using the physical properties of the
cores in our sample as inputs to a spinning dust model, we predict the expected
level of emission at a wavelength of 1cm for four different very small dust
grain abundances, which we constrain by comparing to 1cm CARMA observations.
For all of our cores we find a depletion of very small grains, which we suggest
is due to the process of grain growth. This work represents the first time that
spinning dust emission has been used to constrain the physical properties of
interstellar dust grains.

Astrophysics of Galaxies