2017/05/18 by Todor V. Veltchev, Veltchev, Todor, Sava Donkov +3
Chemistry · Engineering · Physics and Astronomy · #Astrophysics and Star Formation Studies #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #Phase Equilibria and Thermodynamics #Spectroscopy and Laser Applications
paper · pdf · doi:10.48550/arxiv.1705.06550
openalex publication_date 2017/05/18 · openalex created_date 2017/05/26 · openalex updated_date 2026/07/28
We present a method to derive the density scaling relation ⟨ n⟩ ∝ L-α in regions of star formation or in their turbulent vicinities from straightforward binning of the column-density distribution (N-pdf). The outcome of the method is studied for three types of N-pdf: power law (7/5≤α≤5/3), lognormal (0.7\lesssimα\lesssim1.4) and combination of lognormals. In the last case, the method of Stanchev et al. (2015) was also applied for comparison and a very weak (or close to zero) correlation was found. We conclude that the considered `binning approach' reflects rather the local morphology of the N-pdf with no reference to the physical conditions in a considered region. The rough consistency of the derived slopes with the widely adopted Larson's (1981) value α∼1.1 is suggested to support claims that the density-size relation in molecular clouds is indeed an artifact of the observed N-pdf.