Similar complex kinematics within two massive, filamentary infrared dark clouds

摘要: Infrared dark clouds (IRDCs) are thought to be potential hosts of the elusive early phases high-mass star formation. Here we conduct an in-depth kinematic analysis one such IRDC, G034.43+00.24 (Cloud F), using high sensitivity and spectral resolution IRAM-30m N2H+ (1 − 0) C18O observations. To disentangle complex velocity structure within this cloud use Gaussian decomposition hierarchical clustering algorithms. We find that four distinct coherent components present Cloud F. The properties these compared those found in a similar G035.39-00.33 H). both have: densities (inferred by their identification N2H+), trans-to-supersonic non-thermal dispersions with Mach numbers ∼ 1.5 4, separation 3 km s−1, mean red-shift 0.3 s−1 between (dense gas) emission (envelope gas). latter could suggest share common formation scenario. investigate kinematics larger-scale F structures, lower-density-tracing 13CO A good correspondence is identified observations most prominent component data. IRDC only small part much larger structure, which appears inter-arm filament Milky Way.