2018A&A...617A.125C


C.D.S. - SIMBAD4 rel 1.7 - 2020.04.08CEST12:25:29

2018A&A...617A.125C - Astronomy and Astrophysics, volume 617A, 125-125 (2018/9-1)

Probability distribution functions of gas surface density in M 33.

CORBELLI E., ELMEGREEN B.G., BRAINE J. and THILKER D.

Abstract (from CDS):


Aims. We examine the interstellar medium (ISM) of M 33 to unveil fingerprints of self-gravitating gas clouds throughout the star-forming disk.
Methods. The probability distribution functions (PDFs) for atomic, molecular, and total gas surface densities are determined at a resolution of about 50pc over regions that share coherent morphological properties and considering cloud samples at different evolutionary stages in the star formation cycle.
Results. Most of the total gas PDFs are well fit by log-normal functions whose width decreases radially outward. Because the HI velocity dispersion is approximately constant throughout the disk, the decrease in PDF width is consistent with a lower Mach number for the turbulent ISM at large galactocentric radii where a higher fraction of HI is in the warm phase. The atomic gas is found mostly at face-on column densities below NHlim=2.5x1021cm–2, with small radial variations of NHlim. The molecular gas PDFs do not show strong deviations from log-normal functions in the central region where molecular fractions are high. Here the high pressure and rate of star formation shapes the PDF as a log-normal function, dispersing self-gravitating complexes with intense feedback at all column densities that are spatially resolved. Power-law PDFs for the molecules are found near and above NHlim, in the southern spiral arm and in a continuous dense filament extending at larger galactocentric radii. In the filament nearly half of the molecular gas departs from a log-normal PDF, and power laws are also observed in pre-star-forming molecular complexes. The slope of the power law is between -1 and -2. This slope, combined with maps showing where the different parts of the power law PDFs come from, suggests a power-law stratification of the density within molecular cloud complexes, in agreement with the dominance of self-gravity.

Abstract Copyright: © ESO 2018

Journal keyword(s): ISM: clouds - galaxies: individual: M 33 - galaxies: ISM - ISM: molecules - turbulence

Status at CDS:  

Simbad objects: 6

goto Full paper

goto View the reference in ADS

Number of rows : 6

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 M 33 GiG 01 33 50.904 +30 39 35.79 6.17 6.27 5.72     ~ 5086 1
2 NGC 604 HII 01 34 32.1 +30 47 01           ~ 540 0
3 NAME Perseus Cloud SFR 03 35.0 +31 13           ~ 1035 0
4 NAME Taurus Complex SFR 04 41.0 +25 52           ~ 3405 0
5 NAME Rosette Nebula HII 06 31 40 +04 57.8           ~ 439 1
6 NAME ROSETTE MOL CLOUD MoC 06 34.7 +04 02           ~ 225 0

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2018A&A...617A.125C and select 'bookmark this link' or equivalent in the popup menu


2020.04.08-12:25:29

© Université de Strasbourg/CNRS

    • Contact