Science with an ngVLA: Molecular Clouds in Galaxies
  Stars form in cold clouds of predominantly molecular (H2) gas. We are just
beginning to understand how the formation, properties, and destruction of these
clouds varies across the universe. In this chapter, we describe how the thermal
line imaging capabilities of the proposed next generation Very Large Array
(ngVLA) could make major contributions to this field. Looking at CO emission,
the proposed ngVLA would be able to quickly survey the bulk properties of
molecular clouds across the whole nearby galaxy population. This includes many
unique very nearby northern targets (e.g., Andromeda) inaccessible to ALMA.
Such surveys offer a main observational constraint on the formation,
destruction, lifetime, and star formation properties of clouds. Targeting
specific regions, the ngVLA will also be able to heavily resolve clouds in the
nearest galaxies. This will allow detailed studies of the substructure and
kinematics --- and so the internal physics --- of clouds across different
chemical and dynamical environments.
