J/A+A/677/A59 SigMA clusters in Sco-Cen (Ratzenboeck+, 2023)
Significance mode analysis (SigMA) for hierarchical structures.
An application to the Sco-Cen OB association.
Ratzenboeck S., Grossschedl J., Moeller T., Alves J., Bomze I., Meingast M.
<Astron. Astrophys. 677, A59 (2023)>
=2023A&A...677A..59R 2023A&A...677A..59R (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Positional data ; Stars, distances ; Optical
Keywords: methods: data analysis -
open clusters and associations: individual: Sco-Cen -
solar neighborhood - ISM: clouds
Abstract:
We present a new clustering method, significance mode analysis
(SigMA), for extracting co-spatial and co-moving stellar populations
from large-scale surveys such as ESA Gaia. The method studies the
topological properties of the density field in the multidimensional
phase space. We validated SigMA on simulated clusters and find that it
outperforms competing methods, especially in cases where many clusters
are closely spaced. We applied the new method to Gaia DR3 data of the
closest OB association to Earth, Scorpio-Centaurus (Sco-Cen), and find
more than 13000 co-moving young objects, about 19% of which have a
substellar mass. SigMA finds 37 co-moving clusters in Sco-Cen. These
clusters are independently validated by their narrow
Hertzsprung-Russell diagram sequences and, to a certain extent, by
their association with massive stars too bright for Gaia, and are
hence unknown to SigMA. We compared our results with similar recent
work and find that the SigMA algorithm recovers richer populations, is
able to distinguish clusters with velocity differences down to about
0.5km/s, and reaches cluster volume densities as low as
0.01sources/pc3. The 3D distribution of these 37 coeval clusters
implies a larger extent and volume for the Sco-Cen OB association than
typically assumed in the literature. Additionally, we find the
association more actively star-forming and dynamically complex than
previously thought. We confirm that the star-forming molecular clouds
in the Sco-Cen region, namely, Ophiuchus, L134/L183, Pipe Nebula,
Corona Australis, Lupus, and Chamaeleon, are part of the Sco-Cen
association. The application of SigMA to Sco-Cen demonstrates that
advanced machine learning tools applied to the superb Gaia data allows
an accurate census of the young populations to be constructed, which
in turn allows us to quantify their dynamics and recreate the recent
star formation history of the local Milky Way.
Description:
This provided table contains the source selection and cluster
identification of the Sco-Cen OB association as presented in the
associated paper. We provide basic and derived Gaia DR3 information
which includes source identifiers, Galactic Cartesian positions,
proper motions, associated uncertainty regions for positional and
kinematic quantities and the determined stability score, inferred
radial velocities, and SigMA cluster identifiers for each source.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 133 37 Overview of the 37 SigMA clusters in Sco-Cen,
assigned to seven subregions
tablee1.dat 489 13103 Sco-Cen cluster information
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See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- SigMA [1/37] Membership label for each source
(co-moving cluster identification number)
4- 7 A4 --- Region Subregion (1)
9- 24 A16 --- Group Group name
26- 36 A11 --- Bstar Brightest star (2)
38- 41 I4 --- Nr Number of stars
43- 48 F6.2 deg GLON Median Galactic longitude (3)
49 A1 --- --- [+]
50- 53 F4.2 deg E_GLON Upper 1σ error on GLON
54 A1 --- --- [-]
55- 58 F4.2 deg e_GLON Lower 1σ error on GLON
60- 65 F6.2 deg GLAT Median Galactic latitude (3)
66 A1 --- --- [+]
67- 70 F4.2 deg E_GLAT Upper 1σ error on GLAT (4)
71 A1 --- --- [-]
72- 75 F4.2 deg e_GLAT Lower 1σ error on GLAT (4)
77- 81 F5.2 mas plx Median parallax (3)
82 A1 --- --- [+]
83- 86 F4.2 mas E_plx Upper 1σ error on plx (4)
87 A1 --- --- [-]
88- 91 F4.2 mas e_plx Lower 1σ error on plx (4)
93- 95 I3 pc Dist Distance (3)
96 A1 --- --- [+]
97- 98 I2 pc E_Dist Upper 1σ error on
100 A1 --- --- [-]
101-102 I2 pc e_Dist Lower 1σ error on Dist
104-106 I3 pc X Median X position (3)
107 A1 --- --- [+]
108-109 I2 pc E_X Upper 1σ error on X (4)
110 A1 --- --- [-]
111-112 I2 pc e_X Lower 1σ error on X (4)
114-117 I4 pc Y Median Y position (3)
118 A1 --- --- [+]
119-120 I2 pc E_Y Upper 1σ error on Y (4)
121 A1 --- --- [-]
122-123 I2 pc e_Y Lower 1σ error on Y (4)
125-127 I3 pc Z Median Z position (3)
128 A1 --- --- [+]
129-130 I2 pc E_Z Upper 1σ error on Z (4)
131 A1 --- --- [-]
132-133 I2 pc e_Z Lower 1σ error on Z (4)
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Note (1): Subregions are:
US = Upper Scorpius
UCL = Upper-Centaurus-Lupus
LCC = Lower-Centaurus-Crux
Pipe = include the molecular cloud complexes of Pipe
CrA = Corona Australis
Cham = Chameleon
NE = Northeast group
Note (2): Brightest star that was selected as a member by SigMA. The star
annotation * is used as in the SIMBAD astronomical database (Wenger et al.,
2000A&AS..143....9W 2000A&AS..143....9W) and helps distinguish stellar names from cluster names
throughout the manuscript since some clusters are named after bright stars.
Note (3): Medians of the positional parameters for each cluster including all
cluster members (without considering any stability cut).
Note (4): The given lower and upper uncertainties represent the 1{simga}
scatter around the median. In this scatter, the original measurement
uncertainties of single stellar sources are not considered.
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Byte-by-byte Description of file: tablee1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR3 Gaia DR3 unique source identifier
21- 22 I2 --- SigMA [1/37] Membership label for each source
(co-moving cluster identification number)
24- 28 F5.1 % stability [0/100] Source fidelity measure
30- 48 F19.15 pc Dist Distance to source
50- 69 F20.17 pc E_Dist Upper 1σ distance uncertainty
71- 90 F20.17 pc e_Dist Lower 1σ distance uncertainty
92-111 F20.16 pc X Galactic Cartesian X position
113-133 F21.16 pc Y Galactic Cartesian Y position
135-154 F20.16 pc Z Galactic Cartesian Z position
156-177 F22.19 pc E_X Upper 1σ X uncertainty
179-200 F22.19 pc E_Y Upper 1σ Y uncertainty
202-223 F22.19 pc E_Z Upper 1σ Z uncertainty
225-246 F22.19 pc e_X Lower 1σ X uncertainty
248-269 F22.19 pc e_Y Lower 1σ Y uncertainty
271-292 F22.19 pc e_Z Lower 1σ Z uncertainty
294-315 F22.18 km/s VtRA Tangential velocity in RA direction
317-338 F22.18 km/s VtDE Tangential velocity in DE direction
340-359 F20.18 km/s E_VtRA Upper 1σ VtRA uncertainty
361-380 F20.18 km/s E_VtDE Upper 1σ VtDE uncertainty
382-401 F20.18 km/s e_VtRA Lower 1σ VtRA uncertainty
403-422 F20.18 km/s e_VtDE Lower 1σ VtDE uncertainty
424-444 F21.18 km/s VtRALSR Tangential velocity (RA) in LSR
446-466 F21.18 km/s VtDELSR Tangential velocity (DE) in LSR
468-489 F22.18 km/s RV Estimated radial velocity
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Acknowledgements:
Sebastian Ratzenboeck, sebastian.ratzenboeck(at)univie.ac.at
History:
06-Sep-2023: on-line version
27-Sep-2023: table3 added (from electronic version)
(End) Patricia Vannier [CDS] 23-Jun-2023