SEDIGISM: The kinematics of ATLASGAL filaments
  Analysing the kinematics of filamentary molecular clouds is a crucial step
towards understanding their role in the star formation process. Therefore, we
study the kinematics of 283 filament candidates in the inner Galaxy, that were
previously identified in the ATLASGAL dust continuum data. The $^{13}$CO(2 - 1)
and C$^{18}$O(2 - 1) data of the SEDIGISM survey (Structure, Excitation, and
Dynamics of the Inner Galactic Inter Stellar Medium) allows us to analyse the
kinematics of these targets and to determine their physical properties at a
resolution of 30 arcsec and 0.25 km/s. To do so, we developed an automated
algorithm to identify all velocity components along the line-of-sight
correlated with the ATLASGAL dust emission, and derive size, mass, and
kinematic properties for all velocity components. We find two-third of the
filament candidates are coherent structures in position-position-velocity
space. The remaining candidates appear to be the result of a superposition of
two or three filamentary structures along the line-of-sight. At the resolution
of the data, on average the filaments are in agreement with Plummer-like radial
density profiles with a power-law exponent of p = 1.5 +- 0.5, indicating that
they are typically embedded in a molecular cloud and do not have a well-defined
outer radius. Also, we find a correlation between the observed mass per unit
length and the velocity dispersion of the filament of $m \sim \sigma_v^2$. We
show that this relation can be explained by a virial balance between
self-gravity and pressure. Another possible explanation could be radial
collapse of the filament, where we can exclude infall motions close to the
free-fall velocity.
