J/A+A/640/A1 Portrait Galactic disc (Cantat-Gaudin+, 2020)
Painting a portrait of the Galactic disc with its stellar clusters.
Cantat-Gaudin T., Anders F., Castro-Ginard A., Jordi C., Romero-Gomez M.,
Soubiran C., Casamiquela L., Tarricq Y., Moitinho A., Vallenari A.,
Bragaglia A., Krone-Martins A., Kounkel M.
<Astron. Astrophys. 640, A1 (2020)>
=2020A&A...640A...1C 2020A&A...640A...1C (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Milky Way ; Proper motions ;
Parallaxes, trigonometric
Keywords: open clusters and associations: general - Galaxy: disk
Abstract:
The large astrometric and photometric survey performed by the Gaia
mission allows for a panoptic view of the Galactic disc and in its
stellar cluster population. Hundreds of clusters were only discovered
after the latest Gaia data release (DR2) and have yet to be
characterised. Here we make use of the deep and homogeneous Gaia
photometry down to G=18 to estimate the distance, age, and
interstellar reddening for about 2000 clusters identified with Gaia
DR2 astrometry. We use these objects to study the structure and
evolution of the Galactic disc. We rely on a set of objects with
well-determined parameters in the literature to train an artificial
neural network to estimate parameters from the Gaia photometry of
cluster members and their mean parallax. We obtain reliable parameters
for 1867 clusters. Our new homogeneous catalogue confirms the relative
lack of old clusters in the inner disc (with a few notable
exceptions). We also quantify and discuss the variation of scale
height with cluster age, and detect the Galactic warp in the
distribution of old clusters. This work results in a large and
homogenous cluster catalogue. However, the present sample is still
unable to trace the Outer spiral arm of the Milky Way, which indicates
that the outer disc cluster census might still be incomplete.
Description:
In this paper we compile and derive lists of members for 2017 open
clusters. We employ an artificial neural network to estimate cluster
parameters (extinction Av, distance modulus, and age), obtaining
reliable results for 1867 clusters.
Table1_CDS.dat:
Mean parameters for 2017 clusters. Only 1867 have output parameters from
the neural network.
nodup.dat:
All columns from the Gaia DR2 catalogue, except the membership
probability which was computed with the unsupervised classification
scheme UPMASK applied to the Gaia DR2 proper motions and parallaxes,
and teff50 obtained with StarHorse (Anders et al.,
2019A&A...628A..94A 2019A&A...628A..94A, Cat. I/349).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 172 2017 Mean cluster parameters
nodup.dat 507 234128 Members
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
I/349 : StarHorse, Gaia DR2 photo-astrometric distances (Anders+ 2019)
J/A+A/593/A116 : Open clusters within 1.8 kpc of the Sun (Joshi+, 2016)
J/A+A/601/A19 : Gaia DR1 open cluster members (Gaia Collaboration+, 2017)
J/A+A/618/A93 : Gaia DR2 open clusters in the Milky Way (Cantat-Gaudin+, 2018)
J/A+A/618/A59 : Gaia DR2 confirmed new nearby open clusters
(Castro-Ginard+, 2018)
J/A+A/619/A155 : Open cluster kinematics with Gaia DR2 (Soubiran+, 2018)
J/A+A/624/A126 : New open clusters in Perseus direction (Cantat-Gaudin+, 2019)
J/A+A/627/A35 : New open clusters in Galactic anti-centre
(Castro-Ginard+, 2019)
J/A+A/635/A45 : 570 new open clusters in the Galactic disc
(Castro-Ginard+, 2020)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- Cluster Cluster name
19- 25 F7.3 deg RAdeg [] Mean right ascension of members (ICRS)
at Ep=2015.5
27- 33 F7.3 deg DEdeg Mean declination of members (ICRS)
at Ep=2015.5
35- 41 F7.3 deg GLON Mean Galactic longitude of members
43- 49 F7.3 deg GLAT Mean Galactic latitude of members
51- 55 F5.3 deg r50 Radius containing half the members
57- 60 I4 --- nbstars07 Number of members with proba over 0.7
62- 68 F7.3 mas/yr pmRA* Mean proper motion along RA of members,
pmRA*cosDE
70- 75 F6.3 mas/yr e_pmRA* Standard deviation of pmRA* of members
77- 83 F7.3 mas/yr pmDE Mean proper motion along DE of members
85- 90 F6.3 mas/yr e_pmDE Standard deviation of pmDE of members
92- 97 F6.3 mas plx Mean parallax of members
99-103 F5.3 mas e_plx Standard deviation of parallax of members
105-118 A14 --- Flag Indicates origin of parameters, or the reason
for their absence if missing
120-123 F4.2 [yr] AgeNN ?=- Age (logt) of the cluster
125-129 F5.2 mag AVNN ?=- Extinction Av of the cluster
131-135 F5.2 mag DMNN ?=- Distance modulus of the cluster
137-142 F6.0 pc DistPc ?=- Distance in parsecs
(converted distance modulus)
144-150 F7.0 pc X ?=- X position in Galactic cartesian
coordinates
152-158 F7.0 pc Y ?=- Y position in Galactic cartesian
coordinates
160-165 F6.0 pc Z ?=- Z position in Galactic cartesian
coordinates
167-172 F6.0 pc Rgc ?=- Distance from Galactic centre assuming
the Sun is at 8340pc
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Byte-by-byte Description of file: nodup.dat
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Bytes Format Units Label Explanations
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1- 21 E21.19 deg RAdeg Right ascension (ICRS) at Ep=2015.5
23- 43 E21.18 deg DEdeg Declination (ICRS) at Ep=2015.5
45- 63 I19 --- GaiaDR2 Gaia DR2 source ID
65- 84 E20.18 deg GLON Galactic longitude
86-107 E22.19 deg GLAT Galactic latitude
109-130 E22.18 mas Plx Absolute stellar parallax
132-151 F20.18 mas e_Plx Standard error of parallax
153-174 E22.19 mas/yr pmRA* Proper motion in right ascension direction
(pmRA*cosDE)
176-195 F20.18 mas/yr e_pmRA* Standard error of pmRA*
197-218 E22.19 mas/yr pmDE Proper motion in declination direction
220-239 F20.18 mas/yr e_pmDE Standard error of pmDE
241-264 F24.19 km/s RV ? Spectroscopic radial velocity in the
solar barycentric reference frame
266-286 F21.17 km/s e_RV ? Standard error of radial_velocity
288-301 E14.10 --- RADEcor Correlation between right ascension and
declination
303-316 E14.10 --- RAPlxcor Correlation between right ascension and
parallax
318-331 E14.10 --- RApmRAcor Correlation between right ascension and
proper motion in right ascension
333-346 E14.10 --- RApmDEcor Correlation between right ascension and
proper motion in declination
348-361 E14.10 --- DEPlxcor Correlation between declination and
parallax
363-376 E14.10 --- DEpmRAcor Correlation between declination and
proper motion in right ascension
378-391 E14.10 --- DEpmDEcor Correlation between declination and
proper motion in declination
393-406 E14.10 --- PlxpmRAcor Correlation between parallax and
proper motion in right ascension
408-421 E14.10 --- PlxpmDEcor Correlation between parallax and
proper motion in declination
423-436 E14.10 --- pmRApmDEcor Correlation between proper motion in
right ascension and proper motion in
declination
438-441 I4 --- o_Gmag Number of observations contributing to G
photometry
443-452 F10.7 mag Gmag G-band mean magnitude
454-466 E13.10 mag BP-RP ? BP-RP colour
468-474 F7.5 --- proba Membership probability
476-492 A17 --- Cluster Cluster name
494-507 F14.8 K Teff50 ? Effective temperature (Anders et al.,
2019A&A...628A..94A 2019A&A...628A..94A, Cat. I/349)
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Acknowledgements:
Tristan Cantat-Gaudin, tcantat(at)fqa.ub.edu
History:
28-Jul-2020: on-line version
28-Feb-2022: in table1, units of r50 corrected
(End) Patricia Vannier [CDS] 11-May-2020