Modeling contact binaries, III. Properties of a population of close, massive binaries

Abstract

Among massive stars, binary interaction is the rule rather than the exception. The closest binaries, those with periods of less than about 10 days, undergo mass transfer during core-hydrogen burning, with many of them experiencing a nuclear-timescale contact phase. Current binary population synthesis models predict the mass-ratio distribution of contact binaries to be heavily skewed toward a mass ratio of unity, which is inconsistent with observations. It has been shown that effects of tidal deformation due to the Roche potential, as well as energy transfer in the common layers of a contact binary, alter the internal structure of close binary components. However, previous population studies neglected these effects. We model a population of massive binary stars that undergo mass transfer during core-hydrogen burning, while consistently considering the effects of tidal deformation and energy transfer in contact phases. We use the MESA binary-evolution code to compute large grids of models with primary star masses of $8M_{\odot }$ to $70M_{\odot }$ at Solar metallicity. We then perform a population synthesis study to predict distribution functions of the observational properties of close binary systems, focusing in particular on the mass and luminosity ratio distribution. We find that the effects of tidal deformation and energy transfer have a limited effect on the predicted mass-ratio distribution of massive contact binaries. Only a small fraction of the population has their mass ratio significantly shifted toward a more unequal configuration. However, we suggest that orbital hardening could affect the evolution of contact binaries and their progenitors, and we advocate for a homogeneous set of observed contact binary parameters.

12 pages, 10 Figures, (22 pages, 16 Figs. including appendices). Submitted to A&A

References in corpus (40)

• Array Programming with NumPy
• Modules for Experiments in Stellar Astrophysics (MESA)
• Binary interaction dominates the evolution of massive stars
• Modules for Experiments in Stellar Astrophysics (MESA): Pulsating Variable Stars, Rotation, Convective Boundaries, and Energy Conservation
• Southern Massive Stars at High Angular Resolution: Observational Campaign and Companion Detection
• Modules for Experiments in Stellar Astrophysics (MESA): Time-Dependent Convection, Energy Conservation, Automatic Differentiation, and Infrastructure
• The High Angular Resolution Multiplicity of Massive Stars
• Updated Electron-Conduction Opacities: The Impact on Low-Mass Stellar Models
• How mergers magnetise massive stars
• Toward Complete Statistics of Massive Binary Stars: Penultimate Results from the Cygnus OB2 Radial Velocity Survey
• Coulomb tunneling for fusion reactions in dense matter: Path integral Monte Carlo versus mean field
• Internal mixing of rotating stars inferred from dipole gravity modes
• The Tarantula Massive Binary Monitoring: I. Observational campaign and OB-type spectroscopic binaries
• Skye: A Differentiable Equation of State
• The dynamical stability of W Ursae Majoris-type systems
• Detailed models of interacting short-period massive binary stars
• New Conductive Opacities for White Dwarf Envelopes
• The Tarantula Massive Binary Monitoring: III. Atmosphere analysis of double-lined spectroscopic systems
• The Tarantula Massive Binary Monitoring VI: Characterisation of hidden companions in 51 single-lined O-type binaries, a flat mass-ratio distribution, and black-hole binary candidates
• Probing the temperature gradient in the core boundary layer of stars with gravito-inertial modes: the case of KIC7760680
• Structure and evolution of low-mass W UMa type systems -- II. with angular momentum loss
• The Tarantula Massive Binary Monitoring. IV. Double-lined photometric binaries
• Pre-collapse Properties of Superluminous Supernovae and Long Gamma-Ray Burst Progenitor Models
• The B-type Binaries Characterisation Programme I. Orbital solutions for the 30 Doradus population
• A dearth of short-period massive binaries in the young massive star forming region M17: Evidence for a large orbital separation at birth?
• A synthetic population of Wolf-Rayet stars in the LMC based on detailed single and binary star evolution models
• A magnetic massive star has experienced a stellar merger
• Constraining the Overcontact Phase in Massive Binary Evolution I. Mixing in V382 Cyg, VFTS 352, and OGLE SMC-SC10 108086
• A relation between the radial velocity dispersion of young clusters and their age: Evidence for hardening as the formation scenario of massive close binaries
• Properties of six short-period massive binaries: a study of the effects of binarity on surface chemical abundances
• The Binarity of Early-type Stars from LAMOST Medium-resolution Spectroscopic Survey
• Modeling overcontact binaries, I. The effect of tidal deformation
• V606 Cen: A Newly Formed Massive Contact Binary in a Hierarchical Triple System
• Modeling contact binaries, II. The effect of energy transfer
• MY Camelopardalis, a very massive merger progenitor
• The massive multiple system HD 64315
• Constraining the overcontact phase in massive binary evolution -- II. Period stability of known O+O overcontact systems
• Multiplicity of northern bright O-type stars with optical long baseline interferometry
• V745\,Cassiopeia: an interacting young massive binary in a multiple star system
• The spectroscopic binary fraction of the young stellar cluster M17

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