The Orbital Nature of 81 Ellipsoidal Red Giant Binaries in the Large Magellanic Cloud

Abstract

In this paper, we collect a sample of 81 ellipsoidal red giant binaries in the Large Magellanic Cloud (LMC), and we study their orbital natures individually and statistically. The sample contains 59 systems with circular orbits and 22 systems with eccentric orbits. We derive orbital solutions using the 2010 version of the Wilson-Devinney code. The sample is selection-bias corrected, and the orbital parameter distributions are compared to model predictions for the LMC and to observations in the solar vicinity. The masses of the red giant primaries are found to range from about 0.6 to 9 Msun with a peak at around 1.5 Msun, in agreement with studies of the star formation history of the LMC, which find a burst of star formation beginning around 4 Gyr ago. The observed distribution of mass ratios q=m2/m1 is more consistent with the flat q distribution derived for the solar vicinity by Raghavan et al. than it is with the solar vicinity q distribution derived by Duquennoy & Mayor. There is no evidence for an excess number of systems with equal mass components. We find that about 20% of the ellipsoidal binaries have eccentric orbits, twice the fraction estimated by Soszynski et al. Our eccentricity evolution test shows that the existence of eccentric ellipsoidal red giant binaries on the upper parts of the red giant branch (RGB) can only be explained if tidal circularization rates are ~1/100 the rates given by the usual theory of tidal dissipation in convective stars.

arXiv comment16 Pages,15 Figures, 2 Tables

References in corpus (22)

• Evolution of binary stars and the effect of tides on binary populations
• A Survey of Stellar Families: Multiplicity of Solar-Type Stars
• Compact Object Modeling with the StarTrack Population Synthesis Code
• Scaled solar tracks and isochrones in a large region of the Z-Y plane I. From the ZAMS to the TP-AGB end for 0.15 - 2.5 Mo stars
• The Wide Field Spectrograph (WiFeS)
• A Robust Measure of Tidal Circularization in Coeval Binary Populations: The solar-type spectroscopic Binary Population in The Open Cluster M35
• Improved Color-Temperature Relations and Bolometric Corrections for Cool Stars
• Asteroseismology of red giants from the first four months of Kepler data: Fundamental parameters
• Asteroseismic classification of stellar populations among 13000 red giants observed by Kepler
• Bump Cepheids in the Magellanic Clouds: Metallicities, the Distances to the LMC and SMC, and the Pulsation-Evolution Mass Discrepancy
• The Wide Field Spectrograph (WiFeS): Performance and Data Reduction
• Clustering of Local Group distances: publication bias or correlated measurements? I. The Large Magellanic Cloud
• Direct N-Body Modeling of the Old Open Cluster NGC 188: A Detailed Comparison of Theoretical and Observed Binary Star and Blue Straggler Populations
• Synthetic Spectra and Color-Temperature Relations of M Giants
• The pulsation modes, masses and evolution of luminous red giants
• The age-metallicity relationship of the Large Magellanic Cloud field star population from wide-field Washington photometry
• Variable stars in the Magellanic Clouds: II. The data and infrared properties
• The Properties of Long-Period Variables in the Large Magellanic Cloud from MACHO
• Predicting the Fate of Binary Red Giants Using the Observed Sequence E Star Population: Binary Planetary Nebula Nuclei and Post-RGB Stars
• Eccentric Ellipsoidal Red Giant Binaries in the LMC: Complete Orbital Solutions and Comments on Interaction at Periastron
• Ellipsoidal Variability and the Difference between Sequence D and E Red Giants
• Radial Velocity Curves of Ellipsoidal Red Giant Binaries in the Large Magellanic Cloud

Cited by in corpus (13)

• Orbital properties of binary post-AGB stars
• Multiple Stellar Evolution: a population synthesis algorithm to model the stellar, binary, and dynamical evolution of multiple-star systems
• Binary evolution along the Red Giant Branch with BINSTAR: The barium star perspective
• Photometric Analysis of the OGLE Heartbeat Stars
• The OGLE Collection of Variable Stars. One Thousand Heartbeat Stars in the Galactic Bulge and Magellanic Clouds
• Formation and Evolution of Accreting Compact Objects
• Compact Objects in close orbits as Gravitational Wave Sources: Formation Scenarios and Properties
• Gaia Barium Dwarfs and Their Ostensibly Ordinary Counterparts
• Evidence for the Keplerian orbit of a close companion around a giant star
• A comprehensive Gaia view of ellipsoidal and rotational red giant binaries
• Post-AGB Binaries as Interacting Systems
• A hundred new eclipsing binary system candidates studied in a near-infrared window in the VVV survey
• Evolving Low- and Intermediate-Mass Binaries: Departures from Classical Theory