The segregation of starless and protostellar clumps in the Hi-GAL
  l=224deg region
  Stars form in dense, dusty structures, which are embedded in larger clumps of
molecular clouds often showing a clear filamentary structure on large scales (>
1pc). One of the best-studied regions in the Hi-GAL survey can be observed
toward the l=224deg field. Here, a filamentary region has been studied and it
has been found that protostellar clumps are mostly located along the main
filament, whereas starless clumps are detected off this filament and are
instead found on secondary, less prominent filaments. We want to investigate
this segregation effect and how it may affect the clumps properties. We mapped
the 12CO(1-0) line and its main three isotopologues toward the two most
prominent filaments observed toward the l=224deg field using the Mopra radio
telescope, in order to set observational constraints on the dynamics of these
structures and the associated starless and protostellar clumps. Compared to the
starless clumps, the protostellar clumps are more luminous, more turbulent and
lie in regions where the filamentary ambient gas shows larger linewidths. We
see evidence of gas flowing along the main filament, but we do not find any
signs of accretion flow from the filament onto the Hi-GAL clumps. We analyze
the radial column density profile of the filaments and their gravitational
stability. The more massive and highly fragmented main filament appears to be
thermally supercritical and gravitationally bound, assuming that all of the
non-thermal motion is contributing thermal-like support, suggesting a later
stage of evolution compared to the secondary filament. The status and
evolutionary phase of the Hi-GAL clumps would then appear to correlate with
that of the host filament.
