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Infrared dark clouds are massive, dense clouds seen in extinction against the IR Galactic background. Many of these objects appear to be on the verge of star and star cluster formation. Our aim is to understand the physical properties of IRDCs in very early evolutionary phases. We selected the filamentary IRDC G351.77 - 0.51, which is remarkably IR quiet at 8{mu}m. As a first step, we observed mm dust continuum emission and rotational lines of moderate and dense gas tracers to characterise different condensations along the IRDC and study the velocity field of the filament. Our initial study confirms coherent velocity distribution along the infrared dark cloud ruling out any coincidental projection effects. Excellent correlation between MIR extinction, mm continuum emission and gas distribution is found. Large-scale turbulence and line profiles throughout the filament is indicative of a shock in this cloud. Excellent correlation between line width, and MIR brightness indicates turbulence driven by local star formation.
An estimate of the degree of CO-depletion ($f_D$) provides information on the physical conditions occurring in the innermost and densest regions of molecular clouds. A key parameter in these studies is the size of the depletion radius, i.e. the radiu
The fragmentation of a molecular cloud that leads to the formation of high-mass stars occurs on a hierarchy of different spatial scales. The large molecular clouds harbour massive molecular clumps with massive cores embedded in them. The fragmentatio
Molecular line images of 13CO, C18O, CN, CS, CH3OH, and HNCO are obtained toward the spiral arm of M51 at a 7 times 6 resolution with the Combined Array for Research in Millimeter-wave Astronomy (CARMA). Distributions of the molecules averaged over a
We use the hydrodynamical simulation of our inner Galaxy presented in Armillotta et al. (2019) to study the gas distribution and kinematics within the CMZ. We use a resolution high enough to capture the gas emitting in dense molecular tracers such as