  Bailey & Basu (2014) show analysis of density and mass-to-flux ratio maps for
simulations with either an ionisation profile which takes into account
photoionisation (step-like profile) or a cosmic ray only ionisation profile. We
extend this study to analyse the effect of these ionisation profiles on
velocity structures, kinematics, and synthetic spectra. Clump regions are found
to occur at the convergence of two flows with a low velocity region and
velocity direction transition occurring at the junction. Models with evident
substructure show that core formation occurs on the periphery of these velocity
valleys. Analysis of synthetic spectra reveals the presence of large
non-thermal components within low-density gas, especially for models with the
step-like ionisation profile. All cores show small, sub-thermal relative
motions compared to background gas. Large deviations within this analysis are
due to the line of sight intersecting low- and high-density regions across the
velocity switch transition. Positive deviations correspond to a foreground core
moving away from the observer while negative deviations correspond to a
background core moving toward the observer. Comparison of velocities resulting
from different ionisation profiles suggest that high ionisation fractions yield
supersonic velocities, up to two times the sound speed, while regions with low
ionisation fractions tend to be subsonic or mildly supersonic. This suggests
that the transition to coherence within cores could be a transition between
high and low ionisation fractions within the gas.

Solar and Stellar Astrophysics