Interplay between Young Stars and Molecular Clouds in the Ophiuchus
  Star-forming Complex
  We present spatial and kinematic correlation between the young stellar
population and the cloud clumps in the Ophiuchus star-forming region. The
stellar sample consists of known young objects at various evolutionary stages,
taken from the literature, some of which are diagnosed with Gaia EDR3 parallax
and proper-motion measurements. The molecular gas is traced by the 850 $\mu$m
Submillimetre Common-User Bolometer Array-2 image, reaching $\sim$2.3 mJy
beam$^{-1}$, the deepest so far for the region, stacked from the James Clerk
Maxwell Telescope/Transient program aiming to detect submillimeter outburst
events. Our analysis indicates that the more evolved sources, namely the class
II and III young stars, are located further away from clouds than class I and
flat-spectrum sources that have ample circumstellar matter and are closely
associated with natal clouds. Particularly the class II and III population is
found to exhibit a structured spatial distribution indicative of passage of
shock fronts from the nearby Sco-Cen OB association thereby compressing clouds
to trigger star formation, with the latest starbirth episode occurring now in
the densest cloud filaments. The young stars at all evolutionary stages share
similar kinematics. This suggests that the stellar patterns trace the relics of
parental cloud filaments that now have been dispersed.
