J/A+A/672/A29 78 Galactic Open cluster structural parameters (Cordoni+, 2023)
Photometric binaries, mass functions and structural parameters of
78 Galactic Open clusters.
Cordoni G., Milone A.P., Marino A.F., Vesperini E., Dondoglio E.,
Vittoria Legnardi M., Mohandasan A., Carlos M., Lagioia E.P., Jang S.,
Ziliotto T.
<Astron. Astrophys. 672, A29 (2023)>
=2023A&A...672A..29C 2023A&A...672A..29C (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Milky Way ; Stars, double and multiple ;
Morphology
Keywords: techniques: photometric - binaries: close -
Hertzsprung-Russell and C-M diagrams - stars: luminosity function -
mass function - open clusters and associations: general
Abstract:
Binary stars play a crucial role in the understanding of the formation
and evolution of star clusters and their stellar populations. We use
Gaia Data Release 3 to homogeneously analyze 78 Galactic open clusters
and the unresolved binary systems composed of two main-sequence (MS)
stars they host.
We first investigated the clusters' structural parameters, such as the
core radius and the central density and determined interpolating the
density profile of each cluster, the cluster mass function (MF), and
total mass. We measured the fraction of binaries with a large mass
ratio and the fraction of blue straggler stars (BSSs), and, finally,
we investigated possible connections between the populations of binary
stars and BSSs with the main parameters of the host cluster.
Remarkably, we find that the mass functions (MFs) of 78 analyzed open
clusters follow a similar trend and are well reproduced by two single
power-law functions, with a change in slope around masses of
1M☉. The fraction of binary stars ranges from ∼15% to more than
∼60% without significant correlation with the mass and the age of the
host cluster. Moreover, we detect hints of a correlation between the
total fraction of binary stars and the central density of the host
cluster. We compared the fraction of binary stars with that of BSSs,
finding that clusters with high and low central density exhibit
different trends.
The fraction of binaries does not significantly change with the mass
of the primary star and the mass ratio. The radial distribution of
binary stars depends on cluster age. The binaries of clusters younger
than ∼800Myr typically show a flat radial distribution, with some
hints of a double peak. In contrast, the binaries of the remaining
clusters are more centrally concentrated than the single stars,
similar to what is observed in globular clusters.
Description:
Structural parameters, mass functions, unresolved binary stars and
blue stragglers fractions are computed for 78 Galactic Open clusters
by exploiting Gaia DR3 photometry and astrometry.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablec1.dat 157 78 Cluster positions, proper motions, parameters
and density profiles
tablec2.dat 138 78 Mass functions, masses, binary and blue
stragglers function for 78 open clusters
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See also:
J/A+A/618/A93 : Gaia DR2 open clusters in the Milky Way (Cantat-Gaudin+ 2018)
J/A+A/623/A108 : Age of 269 GDR2 open clusters (Bossini+, 2019)
J/MNRAS/504/356 : Updated parameters of 1743 open clusters (Dias+, 2021)
Byte-by-byte Description of file: tablec1.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Cluster identification
14- 21 F8.4 deg RAdeg Right ascension (J2000.0) (1)
23- 30 F8.4 deg DEdeg Right ascension (J2000.0) (1)
32- 38 F7.3 mas/yr pmRA Proper motion in RA (1)
40- 46 F7.3 mas/yr pmDE Proper motion in DE (1)
48- 52 F5.3 mas plx Parallax (1)
54- 59 F6.3 mag Dist Distance modulus (1)
61- 65 F5.3 [yr] logAge Logarithm of Age (1)
67- 72 F6.3 [-] [Fe/H] Metallicity (1)
74- 78 F5.3 mag Av Extiction Av of cluster (1)
80- 83 I4 --- Nstar Number of cluster members
85 I1 --- dr [0/1] Flag indicating if differential
reddening correction applied
87- 95 F9.6 arcmin rc Core radius in arcmin
97-104 F8.6 arcmin e_rc Uncertainty in core radius
106-113 F8.6 pc rcpc Core radius in parsec
115-122 F8.6 pc e_rcpc Uncertainty in core radius
124-132 F9.6 arcmin-2 mu Central density in stars/arcmin2
134-141 F8.6 arcmin-2 e_mu Uncertainty in central density
in stars/arcmin2
143-149 E7.2 pc-2 mupc Central density in stars/parsec2
151-157 E7.2 pc-2 e_mupc Uncertainty in central density
in stars/parsec2
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Note (1): Parameters from
Cantat-Gaudin et al. (2018A&A...618A..93C 2018A&A...618A..93C, Cat. J/A+A/618/A93),
Bossini et al. (2019A&A...623A.108B 2019A&A...623A.108B, Cat. J/A+A/623/A108) and
Dias et al. (2021MNRAS.504..356D 2021MNRAS.504..356D, Cat. J/MNRAS/504/356).
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Byte-by-byte Description of file: tablec2.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Cluster identification
14- 19 F6.3 --- mf-all Mass function slope, all stars
21- 25 F5.3 --- e_mf-all Error mass function slope, all stars
27- 32 F6.3 --- mf-low Mass function slope, low-mass stars
34- 38 F5.3 --- e_mf-low Error mass function slope, low-mass stars
40- 45 F6.3 --- mf-high Mass function slope, high-mass stars
47- 51 F5.3 --- e_mf-high Error mass function slope, high-mass stars
53- 61 F9.3 --- mass-single Cluster mass from single-slope mass
function
63- 71 F9.6 arcmin Rhalfmass Half-mass radius
73- 81 F9.4 Myr trh Half-mass relaxation time (1)
83- 86 F4.2 --- qlim Minimum mass ratio (qlim) considered to
density binary stars
88- 92 F5.3 --- fbin-qlim Binary fraction with q>qlim
94- 98 F5.3 --- e_fbin-qlim Error on binary fraction with q>qlim
100-104 F5.3 --- fbin-tot Total extrapolated binary fraction
with q>qlim
106-110 F5.3 --- e_fbin-tot Error total extrapolated binary
fraction with q>qlim
112-117 F6.3 --- fbincore-tot Core total binary fraction
(only for clusters with Nstar>500)
119-123 F5.3 --- e_fbincore-tot Error core total binary fraction
125-129 F5.3 --- fbss-MS Blue stragglers fraction with respect to
MS stars with 1mag below urn-off
131-135 F5.3 --- e_fbss-MS Error on blue stragglers fraction with
respect to MS stars with 1mag
below turn-off
137-138 I2 --- Nbss Number of blue straggler stars
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Note (1): Half-mass relaxation time is computed as in Spitzer, L. 1987,
Dynamical evolution of globular clusters.
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Acknowledgements:
Giacomo Cordoni, gcordoni94(at)gmail.com
(End) Patricia Vannier [CDS] 06-Feb-2023