Master catalog of infrared proper motions

This is the first homogeneous proper motion measurement of this quality for more than half of these stars. For Class I and flat-spectrum sources, our results provide a >13-fold increase in available proper motion measurements. We analyzed the positional and kinematic differences between YSO classes and confirmed a previously reported inside-out age segregation from younger to older stars, likely driven by an outward movement of older stars.

No evidence of prolonged hierarchical assembly was found. Instead, the results support a rapid (<1Myr) cluster collapse into a centrally concentrated system. This scenario also accounts for the observed slightly higher 1D velocity dispersion of Class I sources relative to Class flat objects.

YSO radial velocities generally align with the gas velocities measured from the molecular transitions of ^12^CO(3-2), HNC(1-0), HCN(1-0), and show a weaker correlation with N_2_H+(1-0). Some Class II and III objects already appear to be decoupling.