C.D.S. - SIMBAD4 rel 1.7 - 2020.07.08CEST04:37:20

2015A&A...581A..74A - Astronomy and Astrophysics, volume 581A, 74-74 (2015/9-1)

Relationship between the column density distribution and evolutionary class of molecular clouds as viewed by ATLASGAL.


Abstract (from CDS):

We present the first study of the relationship between the column density distribution of molecular clouds within nearby Galactic spiral arms and their evolutionary status as measured from their stellar content. We analyze a sample of 195 molecular clouds located at distances below 5.5kpc, identified from the ATLASGAL 870µm data. We define three evolutionary classes within this sample: starless clumps, star-forming clouds with associated young stellar objects, and clouds associated with HII regions. We find that the N(H2) probability density functions (N-PDFs) of these three classes of objects are clearly different: the N-PDFs of starless clumps are narrowest and close to log-normal in shape, while star-forming clouds and HII regions exhibit a power-law shape over a wide range of column densities and log-normal-like components only at low column densities. We use the N-PDFs to estimate the evolutionary time-scales of the three classes of objects based on a simple analytic model from literature. Finally, we show that the integral of the N-PDFs, the dense gas mass fraction, depends on the total mass of the regions as measured by ATLASGAL: more massive clouds contain greater relative amounts of dense gas across all evolutionary classes.

Abstract Copyright:

Journal keyword(s): ISM: clouds - evolution - ISM: structure - dust, extinction - stars: formation - infrared: ISM

VizieR on-line data: <Available at CDS (J/A+A/581/A74): tablef1.dat>

Status at CDS:   All or part of tables of objects could be ingested in SIMBAD with priority 2.

Simbad objects: 4

goto Full paper

goto View the reference in ADS

Number of rows : 4

N Identifier Otype ICRS (J2000)
ICRS (J2000)
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
1 NGC 6334 HII 17 20 51 -36 06.9           ~ 585 0
2 [CCE98b] 011.11-0.12 Cld 18 10.5 -19 23           ~ 85 1
3 NGC 6618 OpC 18 20 47 -16 10.3           ~ 1484 0
4 NAME Galactic Molecular Ring PoG ~ ~           ~ 38 0

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2015A&A...581A..74A and select 'bookmark this link' or equivalent in the popup menu


© Université de Strasbourg/CNRS

    • Contact