Relationship between molecular cloud structure and density PDFs

TL;DR

This paper introduces a new method to analyze molecular cloud structures by examining the relationship between density PDFs and cloud scale, validated through simulations and observational data.

Contribution

It presents a novel approach linking density PDFs to cloud structure via a mass-density power-law relationship, validated with simulations and Planck data.

Findings

The x' parameter correlates with the slope of the high-density PDF tail.

The method effectively traces cloud structure across different scales.

Results are consistent with hydrodynamical simulations and observational data.

Abstract

Volume and column density PDFs in molecular clouds are important diagnostics for understanding their general structure. We developed a novel approach to trace the cloud structure by varying the lower PDF cut-off and exploring a suggested mass-density relationship with a power-law index $x^\prime$. The correspondence of x' as a function of spatial scale to the slope of the high-density PDF tail is studied. To validate the proposed model, we use results from hydrodynamical simulations of a turbulent self-gravitating cloud and recent data on dust continuum emission from the Planck mission.