The mass-ratio distribution of spectroscopic binary stars

1992 ◽  
Vol 196 (2) ◽  
pp. 299-336 ◽  
Author(s):  
Sake J. Hogeveen
Keyword(s):  
Binary Stars ◽  
Mass Ratio ◽  
Ratio Distribution ◽  
Spectroscopic Binary

scholarly journals A method to deconvolve mass ratio distribution of binary stars

2014 ◽  
Vol 573 ◽  
pp. A86 ◽  
Author(s):  
Michel Curé ◽  
Diego F. Rial ◽  
Julia Cassetti ◽  
Alejandra Christen ◽  
Henri M. J. Boffin
Keyword(s):  
Binary Stars ◽  
Mass Ratio ◽  
Ratio Distribution

scholarly journals Pairing function of visual binary stars

2020 ◽  
Vol 501 (1) ◽  
pp. 769-783
Author(s):  
Dmitry Chulkov
Keyword(s):  
Power Law ◽  
Binary Stars ◽  
Mass Function ◽  
Initial Mass Function ◽  
Distance Distribution ◽  
Favourable Result ◽  
Mass Ratio ◽  
Ratio Distribution ◽  
Single Star ◽  
Visual Binary Stars

ABSTRACT An all-sky sample of 1227 visual binaries based on Washington Double Star catalogue is constructed to infer the initial mass function (IMF), mass ratio, and projected distance distribution with a dedicated population synthesis model. Parallaxes from Gaia DR2 and Hipparcos are used to verify the distance distribution. The model is validated on the single-star Tycho-2 sample and successfully reproduces the observed magnitudes and angular separations. The projected separation distribution follows f(s) ∼ s−1.2 in 102–2 × 103  au range for 1–4.5 m⊙ primary stars. Several algorithms are explored as pairing functions. Random pairing is confidently rejected. Primary-constrained pairing (PCP) and split-core pairing (SCP), the scenarios adopting primary component’s or total system’s mass as fundamental, are considered. The preferred IMF slope is α ∼ 2.8 either way. A simple power-law mass ratio distribution is unlikely, but the introduction of a twin excess provides a favourable result. PCP with f(q) ∼ q−1 is preferred with a tiny twin fraction, models with f(q) ∼ q−1.5 are acceptable when a larger twin excess is allowed. SCP is similar to PCP when a larger slope of the power law is adopted: f(q) ∼ qβ + 0.7.

scholarly journals TODCOR – Two-Dimensional Correlation

2011 ◽  
Vol 7 (S282) ◽  
pp. 371-378
Author(s):  
Shay Zucker
Keyword(s):  
Extrasolar Planets ◽  
Radial Velocities ◽  
Correlation Technique ◽  
Two Dimensional ◽  
Mass Ratio ◽  
Maximum Correlation ◽  
Ratio Distribution ◽  
Spectroscopic Binary ◽  
Low Mass ◽  
Stellar Masses

AbstractTODCOR is a TwO-Dimensional CORrelation technique to measure radial velocities of the two components of a spectroscopic binary. Assuming the spectra of the two components are known, the technique correlates an observed binary spectrum against a combination of the two spectra with different shifts. TODCOR measures simultaneously the radial velocities of the two stars by finding the maximum correlation. The main use of the technique has been to turn single-lined binaries into double-lined systems. This helps to explore the binary mass-ratio distribution, especially the low-mass regime, where the secondaries are usually very faint and therefore hard to detect. The technique has been generalized to study multi-order spectra, and also triple- and quadruple-lined systems. It has several applications in studying extrasolar planets and in the future may even help to dynamically measure stellar masses of binaries through relativistc effects.

scholarly journals High Mass-Ratio Binary Population in Open Clusters: Segregation of Early Type Binaries and an Increasing Binary Fraction with Mass

2021 ◽  
Vol 162 (6) ◽  
pp. 264
Author(s):  
Vikrant V. Jadhav ◽  
Kaustubh Roy ◽  
Naman Joshi ◽  
Annapurni Subramaniam
Keyword(s):  
Binary Stars ◽  
Initial Conditions ◽  
Mass Range ◽  
Reference Population ◽  
Open Clusters ◽  
High Mass ◽  
Mass Ratio ◽  
Ratio Distribution ◽  
Galactic Field ◽  
Radial Segregation

Abstract Binary stars play a vital role in astrophysical research, as a good fraction of stars are in binaries. Binary fraction (BF) is known to change with stellar mass in the Galactic field, but such studies in clusters require binary identification and membership information. Here, we estimate the total and spectral-type high-mass-ratio (HMR) BF (f 0.6) in 23 open clusters using unresolved binaries in color–magnitude diagrams using Gaia DR2 data. We introduce the segregation index (   ) parameter to trace mass segregation of HMR (total and mass) binaries and the reference population. This study finds that in open clusters, (1) HMR BF for the mass range 0.4–3.6 M ⊙ (early M to late B-type stars) has a range of 0.12–0.38 with a peak at 0.12–0.20; (2) older clusters have a relatively higher HMR BF; (3) the mass-ratio distribution is unlikely to be a flat distribution and BF (total) ∼(1.5–2.5) × f 0.6; (4) a decreasing BF (total) from late B to K-type stars, in agreement with the Galactic field stars; (5) older clusters show radial segregation of HMR binaries; (6) B-type and A–F type HMR binaries show radial segregation in some young clusters suggesting a primordial origin. This study will constrain the initial conditions and identify the major mechanisms that regulate binary formation in clusters. Primordial segregation of HMR binaries could result from massive clumps spatially segregated in the collapse phase of the molecular cloud.

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