J/A+A/698/A156 Cluster parameters (Xu+, 2025)
Nearby open clusters with tidal features:
Golden sample selection and 3D structure.
Xu M., Fu X., Chen Y., Li L., Fang M., Zhao H., Liu P., Zuo Y.
<Astron. Astrophys. 698, A156 (2025)>
=2025A&A...698A.156X 2025A&A...698A.156X (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open
Keywords: methods: data analysis - catalogs - parallaxes - proper motions -
open clusters and associations: general -
open clusters: individual: NGC 752
Abstract:
Open clusters offer unique opportunities to study stellar dynamics and
evolution under the influence of their internal gravity, the Milky
Way's gravitational field, and the interactions with encounters. Using
the Gaia DR3 data for a catalog of open clusters within 500 parsecs
that exhibit tidal features reported by the literature, we apply a
novel method based on 3D principal component analysis to select a
"golden sample" of nearby open clusters with minimal line-of-sight
distortions. This approach ensures a systematic comparison of 3D and
2D structural parameters for tidally perturbed clusters. The selected
golden sample includes Blanco 1, Melotte 20, Melotte 22, NGC 2632,
NGC 7092, NGC 1662, Roslund 6 and Melotte 111. We analyze these
clusters by fitting both 2D and 3D King Profiles to their stellar
density distributions. Our results reveal systematic discrepancies,
with most of the golden sample clusters exhibiting larger 3D tidal radii
compared to their 2D counterparts, demonstrating that the 2D
projection effects bias the measured cluster size. Furthermore, the 3D
density profiles show stronger deviations from King profiles at the
tidal radii (Δρ3D>Δ{rho2D), highlighting enhanced
sensitivity to tidal disturbances. Additionally, we investigate the
spatial distribution of cluster members relative to their bulk motion
in the Galactic plane. We find that some clusters exhibit tidal
features oriented perpendicular to their direction of motion, which
can be attributed to the fact that the current surveys only detect the
curved inner regions of the tidal features. In conclusion, this work
offers a golden sample of nearby open clusters that are most reliable
for 3D structure analysis and underscores the necessity of 3D analysis
when characterizing OC morphological asymmetries, determining cluster
size, and identifying tidal features.
Description:
Table 1 lists the coordinate and the principal component analysis
(PCA) parameters of all the 389 clusters from Tarricq et al.
(2022A&A...659A..59T 2022A&A...659A..59T, Cat. J/A+A/659/A59). This table provides the
Clusters' age, the Galactic coordinate l and b, the Galactocentric
Cartesian coordinate X0, Y0, Z0, the 3D PCA first principal axis
vector m, n, and p, as well as the angle between the PCA axis and the
line-of-sight to the cluster center.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 88 389 Cluster parameters
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See also:
I/355 : Gaia DR3 (Gaia Collaboration, 2022)
J/A+A/659/A59 : Structural parameters of 389 local open clusters
(Tarricq+, 2022)
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 (1)
19- 24 F6.2 deg GLON0 Mean Galactic longitude (l_0) (1)
26- 31 F6.2 deg GLAT0 Mean Galactic latitude (b_0) (1)
33- 39 F7.1 pc X0 Median Galactocentric Cartesian X coordinate
(X_0)
41- 47 F7.1 pc Y0 Median Galactocentric Cartesian Y coordinate
(Y_0)
49- 54 F6.1 pc Z0 Median Galactocentric Cartesian Z coordinate
(Z_0)
56- 60 F5.2 --- m PCA first principal axis m vector (m)
62- 66 F5.2 --- n PCA first principal axis n vector (n)
68- 72 F5.2 --- p PCA first principal axis p vector (p)
74- 78 F5.2 deg phi Angle between the PCA axis and line-of-sight
(phi)
80- 83 I4 --- Nstar Number of members (N_star) (1)
85- 88 F4.2 [yr] logAge Cluster age (logt) (logAge(yr)) (1)
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Note (1): Columns coming from (Tarricq et al., 2022A&A...659A..59T 2022A&A...659A..59T,
Cat. J/A+A/659/A59)
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Acknowledgements:
Yang Chen, cy(at)ahu.edu.cn
(End) Patricia Vannier [CDS] 28-Apr-2025