Unresolved binaries and Galactic clusters' mass estimates

Abstract

Binary stars are present in all stellar systems, yet their role is far from being fully understood. We investigate the effect of unresolved binaries in the derivation of open clusters' mass by star counts. We start from the luminosity functions of five open clusters: IC 2714, NGC 1912, NGC 2099, NGC 6834 and NGC 7142. Luminosity functions are obtained via star counts extracted from the 2MASS database. The fraction of binaries is considered to be independent on stellar magnitude. We take into account different assumptions for the binary mass ratio distribution and assign binary masses using the so-called {\it luminosity-limited pairing} method and Monte-Carlo simulations. We show that cluster masses increase when binary stars are appropriately taken into account.

9 pages, 2 figures, 2 tables

References in corpus (27)

• Gaia Data Release 2. Summary of the contents and survey properties
• The Gaia mission
• PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
• A Survey of Stellar Families: Multiplicity of Solar-Type Stars
• Stellar Multiplicity
• The ACS Survey of Galactic Globular Clusters. XII. Photometric Binaries along the Main-Sequence
• From binaries to multiples II: hierarchical multiplicity of F and G dwarfs
• A High Angular Resolution Multiplicity Survey of the Open Clusters alpha Persei and Praesepe
• Main-Sequence Effective Temperatures from a Revised Mass-Luminosity Relation Based on Accurate Properties
• Direct N-Body Modeling of the Old Open Cluster NGC 188: A Detailed Comparison of Theoretical and Observed Binary Star and Blue Straggler Populations
• Exploring the consequences of pairing algorithms for binary stars
• Cluster membership probabilities from proper motions and multiwavelength photometric catalogues: I. Method and application to the Pleiades cluster
• The Binary Second Sequence in Cluster Colour--Magnitude Diagrams
• The Universality of the Companion Mass Ratio Distribution
• A survey for low mass spectroscopic binary stars in the young clusters around sigma Orionis and lambda Orionis
• The stellar mass function, binary content and radial structure of the open cluster Praesepe derived from PPMXL and SDSS data
• What a Local Sample of Spectroscopic Binaries can tell us about the Field-Binary Population
• The binary companion mass ratio distribution: an imprint of the star formation process?
• Evolution of the binary population in young dense star clusters
• Open-cluster density profiles derived using a kernel estimator
• Powerful CMD: A Tool for Colour-Magnitude Diagram Studies
• The Binary Fraction and Mass Segregation in Alpha Persei Open Cluster
• Luminosity and mass function of galactic open clusters: I. NGC 4815
• The effect of unresolved binaries on globular cluster proper-motion dispersion profiles
• On the mass of the Galactic star cluster NGC 4337
• The open cluster NGC 7142: interstellar extinction, distance and age
• How do binaries affect the derived dynamical mass of a star cluster?

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• Goodness-of-fit test for isochrone fitting in the Gaia era. Statistical assessment of the error distribution
• Unresolved multiple stars and Galactic clusters' mass estimates
• Star-by-star dynamical evolution of the physical pair of the Collinder 135 and UBC 7 open clusters
• Looking for Signs of Unresolved Binarity in the Continuum of LAMOST Stellar Spectra