J/A+A/617/A15 Membership probabilities of Pleiades objects (Olivares+, 2018)
The seven sisters DANCe. IV. Bayesian hierarchical model.
Olivares J., Sarro L.M., Moraux E., Berihuete A., Bouy H.,
Hernandez-Jimenez S., Bertin E., Galli P.A.B., Huelamo N., Bouvier J.,
Barrado D.
<Astron. Astrophys. 617, A15 (2018)>
=2018A&A...617A..15O 2018A&A...617A..15O (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Cross identifications ; Combined data
Keywords: methods: data analysis - methods: statistical - proper motions -
stars: luminosity function, mass function -
Galaxy: open clusters and associations: individual: M45
Abstract:
The photometric and astrometric measurements of the Pleiades DANCe DR2
survey provide an excellent test case for the benchmarking of
statistical tools aiming at the disentanglement and characterisation
of nearby young open cluster (NYOC) stellar populations.
We aim to develop,test, and characterise of a new statistical tool
(intelligent system) for the sifting and analysis of NYOC populations.
Using a Bayesian formalism, with this statistical tool we were able to
obtain the posterior distributions of parameters governing the cluster
model. It also used hierarchical bayesian models to establish weakly
informative priors, and incorporates the treatment of missing values
and non-homogeneous (heteroscedastic) observational uncertainties.
From simulations, we estimated that this statistical tool renders
kinematic (proper motion) and photometric (luminosity) distributions
of the cluster population with a contamination rate of 5.8±0.2%.
The luminosity distributions and present day mass function agree with
the ones found in a recent study, on the completeness interval of the
survey. At the probability threshold of maximum accuracy, the
classifier recovers ∼90% of the recently published candidate members
and finds 10% of new ones.
A new statistical tool for the analysis of NYOC is introduced, tested,
and characterised. Its comprehensive modelling of the data properties
allows it to get rid of the biases present in previous works. In
particular, those resulting from the use of only completely observed
(non-missing) data and the assumption of homoskedastic uncertainties.
Also, its Bayesian framework allows it to properly propagate
observational uncertainties into membership probabilities and cluster
velocity and luminosity distributions. Our results are in a general
agreement with those from the literature, although we provide the most
up-to-date and extended list of candidate members of the Pleiades
cluster.
Description:
Membership probabilities and identifiers of 1424893 objects from the
DANCE DR2 data set. To select equal-mass binaries, both p_c and p_emb
should be used. This table contains only the 1424893 objects in the
DANCE DR2 (Bouy et al., 2015, Cat. J/A+A/577/A148) that fulfil the
following criteria:
i) have both proper motions observed,
ii) have at least two photometric entries in the representation space used,
and iii) the colour index i-Ks falls within the range [0.8, 8.0]mag.
For more details, see paper.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 65 1424893 Membership probabilities and identifiers
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See also:
J/A+A/563/A45 : Pleiades cluster membership probabilities (Sarro+, 2014)
J/A+A/577/A148 : The Seven Sisters DANCe. I. Pleiades (Bouy+, 2015)
J/A+A/596/A113 : The Seven Sisters DANCe. II. Pleiades (Barrado+, 2016)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- BouyID Bouy et al., 2015, Cat. J/A+A/577/A148
identifier, JHHMMSS.ss+DDMMSS.s
21- 27 I7 --- SarroID Sarro et al., 2014, Cat. J/A+A/563/A45
identifier
29- 36 F8.6 --- pc Cluster membership probability
38- 45 F8.6 --- pemb Equal-mass binaries membership probability
47- 54 F8.6 --- s_pc Standard deviation of cluster
membership probability
56- 63 F8.6 --- s_pemb Standard deviation of equal-mass binaries
membership probability
65 I1 --- MissingCI [0/1] indicating if colour index i-Ks is absent
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Acknowledgements:
Javier Olivares, javier.olivares-romero(at)u-bordeaux.fr
References:
Bouy et al., Paper I 2015A&A...577A.148B 2015A&A...577A.148B, Cat. J/A+A/577/A148
Barrado et al., Paper II 2016A&A...596A.113B 2016A&A...596A.113B, Cat. J/A+A/596/A113
Olivares et al., Paper III 2018A&A...612A..70O 2018A&A...612A..70O
(End) Javier Olivares [LAB, France], Patricia Vannier [CDS] 29-May-2018