The molecular distribution of the IRDC G351.77-0.51

TL;DR

This study investigates the physical properties and internal dynamics of the IRDC G351.77-0.51, revealing coherent velocity structure, turbulence, and potential early star formation activity in this dark cloud.

Contribution

It provides detailed observational analysis of an IRDC's molecular distribution, velocity field, and turbulence, highlighting early star formation indicators.

Findings

Coherent velocity distribution along the IRDC

Correlation between MIR extinction, mm emission, and gas distribution

Evidence of turbulence and shocks within the cloud

Abstract

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.