Molecular Line Profiles from a Core Forming in a Turbulent Cloud
  We calculate the evolution of molecular line profiles of HCO$^+$ and
C$^{18}$O toward a dense core thatis forming inside a magnetized turbulent
molecular cloud. Features of the profiles can be affected more significantly by
coupled velocity and abundance structures in the outer region than those in the
inner dense part of the core. The velocity structure at large radii is
dominated by a turbulent flow nearby and accretion shocks onto the core, which
resulting in the variation between inward and outward motions during the
evolution of the core. The chemical abundance structure is significantly
affected by the depletion of molecules in the central region with high density
and low temperature. During the evolution of the core, the asymmetry of line
profiles easily changes from blue to red, and vice versa. According to our
study, the observed reversed (red) asymmetry toward some starless cores could
be interpreted as an intrinsic result of outward motion in the outer region of
a dense core, which is embedded in a turbulent environment and still grows in
density at the center.
