VizieR Online Data Catalog: Multiplicity fractions in Gaia open clusters (Donada+, 2023)
Abstract
We model the observed G vs. (BP-RP) Gaia colour-magnitude diagram (CMD) of the selected main-sequence members of each open cluster as a mixture distribution of single stars and unresolved binaries, considering that two Gaussian distributions centred on the single sequence and binary sequence loci introduce the observed scatter in G magnitude. We perform Markov chain Monte Carlo (MCMC) fits for a likelihood function depending (amongst others) on the open cluster's high-mass ratio unresolved multiplicity fraction (integrated over the colour index of the cluster's CMD). We thus derive the high-mass ratio unresolved multiplicity fraction for 202 open clusters. Using a sample of simulated Gaia-like open clusters we estimate that the lowest mass ratio of the systems taken into account in this unresolved multiplicity fraction is 0.6+0.05-0.15; and we estimate too the total multiplicity fraction of systems (both resolved and unresolved) having a mass ratio larger than this value.
Catalogue obtained applying the MCMC fits of our model to the sample of 202 open clusters. It contains their structural parameters taken from Cantat-Gaudin et al. (2020A&A...640A...1C, Cat. J/A+A/640/A1), the number of selected main-sequence members and their minimum and maximum BP-RP intrinsic colour index, the MCMC-fitted parameters of the model (including the unresolved multiplicity fraction of systems with a mass ratio q>Msecondary/Mprimary>0.6+0.05-0.15) and also the estimated total multiplicity fraction (of both resolved and unresolved systems having a mass ratio larger than this value). (1 data file).- Publication:
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VizieR Online Data Catalog
- Pub Date:
- May 2023
- Bibcode:
- 2023yCat..36750089D
- Keywords:
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- Milky Way;
- Clusters: open;
- Optical