Science with an ngVLA: Exploring Protostellar Disk Formation with the
  ngVLA
  The formation and evolution of disks early in the protostellar phase is an
area of study in which the ngVLA is poised to make significant breakthroughs.
The high-sensitivity and resolution at wavelengths of 3~mm and longer will
enable forming disks to be examined with unprecedented detail. The need to
observe dust emission at wavelengths of 3~mm and longer is motivated by the
fact that dust emission at these wavelengths is more likely to be optically
thin, which is essential to understanding the structure of these disks. We
explore the feasibility of detecting and resolving protostellar disks with a
variety of radii, masses, and distances, out to distances as large as 1.5~kpc
using radiative transfer models and simulations with the proposed ngVLA
configuration. We also examine the potential for the ngVLA to enable studies of
grain growth and radial migration of dust particles early in the protostellar
phase with the broad multi-wavelength coverage. Studies of grain growth will
require wavelength coverage extending at least to $\sim$4~cm to characterize
and quantify the location and intensity of free-free emission, which is
expected to be generated at $<$10 AU scales.
