J/MNRAS/500/3027 The SEDIGISM survey: molecular clouds (Duarte-Cabral+, 2021)
The SEDIGISM survey: molecular clouds in the inner Galaxy.
Duarte-Cabral A., Colombo D., Urquhart J.S., Ginsburg A., Russeil D.,
Schuller F., Anderson L.D., Barnes P.J., Beltran M.T., Beuther H.,
Bontemps S., Bronfman L., Csengeri T., Dobbs C.L., Eden D., Giannetti A.,
Kauffmann J., Mattern M., Medina S.-N.X., Menten K.M., Lee M.-Y.,
Pettitt A.R., Riener M., Rigby A.J., Traficante A., Veena V.S., Wienen M.,
Wyrowski F., Agurto C., Azagra F., Cesaroni R., Finger R., Gonzalez E.,
Henning T., Hernandez A.K., Kainulainen J., Leurini S., Lopez S.,
Mac-Auliffe F., Mazumdar P., Molinari S., Motte F., Muller E.,
Nguyen-Luong Q., Parra R., Perez-Beaupuits J.-P., Montenegro-Montes F.M.,
Moore T.J.T., Ragan S.E., Sanchez-Monge A., Sanna A., Schilke P.,
Schisano E., Schneider N., Suri S., Testi L., Torstensson K., Venegas P.,
Wang K., Zavagno A.
<Mon. Not. R. Astron. Soc., 500, 3027-3049 (2021)>
=2021MNRAS.500.3027D 2021MNRAS.500.3027D (SIMBAD/NED BibCode)
ADC_Keywords: Molecular clouds ; Interstellar medium ; Milky Way ;
Positional data ; Velocity dispersion ; Spectra, millimetric/submm
Keywords: ISM: clouds - Galaxy: structure - stars: formation -
galaxies: ISM, star formation
Abstract:
We use the 13CO(2-1) emission from the SEDIGISM (Structure,
Excitation, and Dynamics of the Inner Galactic InterStellar Medium)
high-resolution spectral-line survey of the inner Galaxy, to extract
the molecular cloud population with a large dynamic range in spatial
scales, using the Spectral Clustering for Interstellar Molecular
Emission Segmentation (SCIMES) algorithm. This work compiles a cloud
catalogue with a total of 10663 molecular clouds, 10300 of which we
were able to assign distances and compute physical properties. We
study some of the global properties of clouds using a science sample,
consisting of 6664 well-resolved sources and for which the distance
estimates are reliable. In particular, we compare the scaling
relations retrieved from SEDIGISM to those of other surveys, and we
explore the properties of clouds with and without high-mass star
formation. Our results suggest that there is no single global property
of a cloud that determines its ability to form massive stars, although
we find combined trends of increasing mass, size, surface density, and
velocity dispersion for the sub-sample of clouds with ongoing
high-mass star formation. We then isolate the most extreme clouds in
the SEDIGISM sample (i.e. clouds in the tails of the distributions) to
look at their overall Galactic distribution, in search for hints of
environmental effects. We find that, for most properties, the Galactic
distribution of the most extreme clouds is only marginally different
to that of the global cloud population. The Galactic distribution of
the largest clouds, the turbulent clouds and the high-mass
star-forming clouds are those that deviate most significantly from the
global cloud population. We also find that the least dynamically
active clouds (with low velocity dispersion or low virial parameter)
are situated further afield, mostly in the least populated areas.
However, we suspect that part of these trends may be affected by some
observational biases (such as completeness and survey limitations),
and thus require further follow up work in order to be confirmed.
Description:
In this paper, we use data from the SEDIGISM survey conducted with the
Atacama Pathfinder Experiment 12m submillimetre telescope (APEX;
Gusten et al. 2006A&A...454L..13G 2006A&A...454L..13G). In particular, we use the
13CO(2-1) to extract and characterize the molecular clouds towards
the inner Galaxy. The complete details on the observations, data
reduction and data-quality checks can be found in the survey overview
papers (Schuller et al. 2017A&A...601A.124S 2017A&A...601A.124S, Cat. J/A+A/601/A124,
2021MNRAS.500.3064S 2021MNRAS.500.3064S).
In summary, the SEDIGISM survey observed a total of 84deg2, covering
from -60°=<l=<+18°, and |b|=<0.5°, plus a few extensions
in b towards some regions, as well as an additional field towards the
W43 region (+29°=<l=<+31°). The 13CO(2-1) data that we use
here is the DR1 data set (fully described in Schuller et al.
2021MNRAS.500.3064S 2021MNRAS.500.3064S), which has a typical 1σ sensitivity of
0.8-1.0K (in Tmb) per 0.25km/s channel, and an FWHM beam size,
θMB, of 28arcsec.
From the contiguous portion of the survey (i.e. excluding the W43
field), we extracted the entire molecular cloud population with a
large dynamic range in spatial scales, using the SCIMES algorithm. We
determined the distances to the clouds, using the kinematic distances,
and a number of methods to solve the distance ambiguities (including
masers, IRDC, dark clouds, HISA, distance to the Larson's
size-linewidth relation, distance to the Galactic plane, and
extinction distances). The full catalogue that we release contains
10663 molecular clouds, 10300 of which with measurements of physical
properties.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 926 10663 SEDIGISM catalogue
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See also:
J/A+A/601/A124 : Clouds in SEDIGISM science demonstration field
(Schuller+, 2017)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- ID [1/10663] Internal cloud identifier
7- 23 A17 --- Name Cloud name (SDGLLL.lll+B.bbbb)
25- 47 F23.19 deg GLON Galactic longitude of the cloud's
centroid
49- 71 E23.17 deg GLAT Galactic latitude of the cloud's
centroid
73- 96 F24.19 km/s vLSR Systemic velocity
98- 117 F20.17 km/s sigma Velocity dispersion
119- 139 F21.13 arcsec2 Area Exact footprint area
141- 159 F19.15 arcsec Req Equivalent radius, estimated using the
footprint area
161- 180 F20.15 arcsec a Semi-major axis
182- 201 F20.16 arcsec b Semi-minor axis
203- 222 F20.15 deg PA [] Position angle of the major axis,
with 0° being along the x/l axis
224- 242 F19.16 --- ARmom Aspect ratio from the moments
244- 263 F20.15 arcsec lengthMA Projected geometrical medial axis length
265- 283 F19.15 arcsec widthMA Projected geometrical medial axis width
285- 304 F20.17 --- ARMA Aspect ratio from the medial axis
306- 324 F19.16 K.km/s I13CO Average 13CO(2-1) integrated intensity
<I13^CO_>
326- 344 F19.16 K T13CO Peak 13CO(2-1) intensity
Tpeak13^CO_
346- 364 F19.16 --- SNR Signal-to-noise ratio
366- 371 I6 --- Npix Number of 3D pixels (i.e. voxels) in the
cloud
373- 374 I2 --- Nleaves Number of individual dendrogram leaves
comprised in the cloud
376- 380 F5.1 --- Origfile Name of the field from which the cloud
was originally extracted
382 I1 --- Edge [0/1] Tag identifying whether a cloud
touches an edge of the field
(yes=1, no=0)
384- 388 F5.2 kpc dnear ?=99.99 Near kinematic distance
390- 394 F5.2 kpc e_dnear ?=99.99 Error on dnear
396- 400 F5.2 kpc dfar ?=99.99 Far kinematic distance
402- 406 F5.2 kpc e_dfar ?=99.99 Error on dfar
408- 412 F5.2 kpc d ?=-1 Final adopted distance
414- 433 F20.17 kpc e_d ?=-1 Error on d
435- 436 A2 --- dmet Flag describing the method by which the
final distance was decided (1)
438- 439 A2 --- dsol Flag describing the type of distance
solution (2)
441 I1 --- dreliable [0/1] Flag to indicate sources with a
reliable distance
(1=reliable, 0=non-reliable)
443- 444 I2 --- HISA Flag with the result from our automated
HI self-absorption (HISA) determination
(1=strong HISA, -1=no HISA)
446- 448 I3 --- NAGALtot Total number of ATLAGAL matches
450- 451 I2 --- NAGALperf Number of ATLASGAL perfect matches
453- 454 I2 --- NAGALpart Number of ATLASGAL partial matches
456- 457 I2 --- NAGALnod Number of ATLASGAL matches with no
distance assigned
459 I1 --- HMSF [0/1] Tag identifying whether a cloud
has a high-mass star formation (HMSF)
tracer (1=yes, 0=no)
461- 485 F25.19 pc2 Areapc Exact footprint area in pc2
487- 507 F21.18 pc Reqpc Equivalent radius, estimated using the
footprint area in pc
509- 530 F22.19 pc apc Semi-major axis in pc
532- 553 F22.19 pc bpc Semi-minor axis in pc
555- 576 F22.18 pc lengthMApc Projected geometrical medial axis length
in pc
578- 598 F21.18 pc widthMApc Projected geometrical medial axis width
in pc
600- 625 F26.18 Msun Mass Cloud mass
627- 648 E22.17 cm-2 N Cloud's average column density
650- 669 F20.15 Msun/pc2 Sigma Cloud's average gas surface density
671- 693 F23.18 --- alphavir Virial parameter
695- 715 F21.18 pc Reqd Deconvolved equivalent radius
717- 736 F20.15 Msun/pc2 Sigmad Surface density, calculated using the
deconvolved radius
738- 759 F22.18 --- alphavird Virial parameter, calculating using the
deconvolved radius
761- 781 F21.18 kpc Xsun X in Heliocentric coordinates
783- 806 E24.17 kpc Ysun Y in Heliocentric coordinates
808- 830 E23.17 kpc Zsun Z in Heliocentric coordinates
832- 855 E24.17 kpc Xgal X in Galactocentric coordinates
857- 880 E24.17 kpc Ygal Y in Galactocentric coordinates
882- 904 E23.17 kpc Zgal Z in Galactocentric coordinates
906- 926 F21.18 kpc Rgal Galactocentric distance
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Note (1): Flag as follows:
-1 = No distance information (363/10663)
0 = Exact maser parallax distance (11/10663)
1 = No distance ambiguity (551/10663)
2 = Tangent distance (1080/10663)
3 = Dark cloud (near distance) (77/10663)
4 = IRDC (near distance) (751/10663)
5 = Literature HISA (near distance) (91/10663)
6 = Direct HISA measurement (near distance) (828/10663)
7 = ATLASGAL source at near distance (252/10663)
8 = Solomon distance to GP (near distance) (34/10663)
9 = Size-linewidth scatter (near or far distance) (2263/10663)
10 = ATLASGAL source at far distance (142/10663)
11 = Extinction (near or far distance) (3178/10663)
12 = Ambiguity not solved (defaulted to far) (1042/10663)
Note (2): Flag as follows:
NA = Not Ambiguous (551/10663)
T = Tangent (1080/10663)
N = Near (3698/10663)
F = Far (4960/10663)
M = Maser (11/10663)
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 03-Oct-2023