J/MNRAS/511/2302 Molecular clouds study from 3D extinction maps (Guo+, 2022)
A large catalogue of molecular clouds in the Southern sky.
Guo H.-L., Chen B.-Q., Liu X.-W.
<Mon. Not. R. Astron. Soc., 511, 2302-2312 (2022)>
=2022MNRAS.511.2302G 2022MNRAS.511.2302G (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Interstellar medium ; Star Forming Region ;
Molecular clouds ; Photometry ; Optical ; Infrared ;
Positional data ; Selected areas ; Extinction
Keywords: ISM: clouds - dust, extinction - Galaxy: structure
Abstract:
We present a large catalogue of molecular clouds with accurate
distance estimates in the Southern sky. Based on the three-dimensional
dust extinction map and the best-fitting extinction and distance
information of over 17 million stars presented in Guo et al.
(2021ApJ...906...47G 2021ApJ...906...47G), we have identified 250 dust/molecular clouds in
the Southern sky using a hierarchical structure identification
algorithm. Amongst these are 71 clouds located at high Galactic
latitudes (b < -10°). We have estimated the distances to the
clouds by fitting the extinction versus distance profiles of the lines
of sight overlapping with the clouds, using a simple Gaussian dust
distribution model. The typical uncertainties of the distances are
less than 7 per cent. We also provide the physical properties of the
individual clouds, including the linear radius, mass and surface mass
density.
Description:
Molecular clouds play a crucial role in the processes of star
formation and galaxy evolution. A large catalogue of molecular clouds
with robust property measurements is fundamental for studying the
physical nature and evolution of molecular clouds themselves and for
understanding the process of star formation and ultimately of galaxy
evolution. Most of the studies dealt with molecular clouds in the
Galactic disc of low Galactic latitudes and of regions of high
Galactic latitudes in the northern sky. Only a few works have analysed
the molecular clouds in the Southern sky, especially of regions of
b < -10°. Guo et al. (2021ApJ...906...47G 2021ApJ...906...47G) have presented 3D
extinction maps of the Southern sky based on the multiband photometry
of the SkyMapper Southern Survey Data Release 1 (SMSS DR1; Wolf et al.
2018PASA...35...10W 2018PASA...35...10W, Cat. II/358 and Cat. II/379), Gaia DR2 (Gaia
Collaboration 2018A&A...616A...1G 2018A&A...616A...1G, Cat. I/345), 2MASS (Cutri et al.
2003yCat.2246....0C 2003yCat.2246....0C, Cat. II/246), and the Wide-Field Infrared Survey
Explorer (WISE; Wright et al. 2010AJ....140.1868W 2010AJ....140.1868W), and the stellar
distances calculated from the Gaia DR2 parallaxes (Bailer-Jones et al.
2018AJ....156...58B 2018AJ....156...58B, Cat. I/347). The work of Guo et al. provides us
with an opportunity to fill the gap, (i.e see section Introduction).
From molecular identification method similar to Chen et al.
(2020MNRAS.493..351C 2020MNRAS.493..351C, Cat. J/MNRAS/493/351), we isolate the individual
molecular clouds from the 3D extinction maps, estimate their distances
and calculate their physical properties (i.e see section 3 Method).
Thanks to the work described in section 3.1, 3.2, 3.3, we are able to
identify 250 molecular clouds in the Southern sky from Guo et al.
(2021ApJ...906...47G 2021ApJ...906...47G) 3D extinction maps. The full results are
presented in the table1.dat containing parameters as radius, mass,
surface density and more.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 171 250 Physical properties of our molecular clouds
sample
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See also:
J/A+A/591/A5 : ATLASGAL dense filamentary structures (Li+, 2016)
VII/244 : Atlas and Catalog of Dark Clouds (Dobashi+, 2005)
J/ApJ/834/57 : Milky Way molecular clouds from 12CO
(Miville-Deschenes+, 2017)
II/349 : The Pan-STARRS release 1 (PS1) Survey - DR1 (Chambers+, 2016)
J/ApJ/786/29 : Catalog of distances to molecular clouds (Schlafly+, 2014)
VII/233 : 2MASS All-Sky Extended Source Catalog (XSC)
(IPAC UMass, 2003-2006)
J/ApJ/706/727 : Distance and mass of Infrared Dark Clouds (Marshall+, 2009)
J/PASJ/63/S1 : Atlas and catalog of dark clouds based on 2MASS
(Dobashi+, 2011)
J/A+A/633/A51 : Distances to molecular clouds in SFR (Zucker+, 2020)
II/358 : SkyMapper Southern Sky Survey. DR1.1 (Wolf+, 2018)
II/379 : SkyMapper Southern Sky Survey. DR4 (Onken+, 2024)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
I/347 : Distances to 1.33 billion stars in Gaia DR2
(Bailer-Jones+, 2018)
J/MNRAS/493/351 : A large catalogue of molecular clouds (Chen+, 2020)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID Identifier number (ID)
5- 10 F6.2 deg GLON Galactic longitude (l)
12- 17 F6.2 deg GLAT Galactic latitude (b)
19- 22 I4 pc D Estimated distance with method as explained
in the section 3.2 Distance measurement
(d0)
24- 40 F17.13 pc e_D Mean uncertainty of D (err_d0)
42- 60 F19.12 Msun M Mass of the identified molecular cloud
computed with the equation 7 of the section
3.3 Physical parameters (M)
62- 80 F19.13 pc2 S Estimated cloud surface area computed with
the equation 5 of the section 3.3 Physical
parameters (S)
82- 98 F17.14 pc r Linear cloud radius computed with the
equation 6 of the section 3.3 Physical
parameters (r)
100- 116 F17.13 Msun/pc2 Sigma Surface density computed with M/S from the
section 3.3 Physical parameters (Σ)
118- 134 F17.14 deg2 Omega Solid angle computed with the equation 4 of
the section 3.3 Physical parameters
(Ω)
136- 152 F17.15 mag DeltaAr Total r-band extinction contributed by the
dust in the cloud taken from the distance
measurements analysis of the section 3.2
(δAr)
154- 171 F18.13 pc Deltad The width of the extinction jump produced
by the dust in the cloud taken from the
distance measurements analysis of the
section 3.2 (δd)
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History:
From electronic version of the journal
(End) Luc Trabelsi [CDS] 22-Jan-2025