Showing papers on "Binary system published in 2022"

Binary orbital evolution driven by a circumbinary disc

Abstract: The question whether the interaction of a circumbinary disc with the central binary system leads to a shrinking or to an expansion of the binary orbit has attracted considerable interest as it impacts the evolution of binary black holes and stellar binary stars in their formation phase. We performed two-dimensional hydrodynamical simulations of circumbinary discs for a large parameter set of disc viscosities and thicknesses and for two di ff erent binary mass ratios for binaries on circular orbits. We measured the net angular momentum and mass transfer between disc and binary system, and evaluated the normalised specific angular momentum accretion, j s . This was compared to the theoretical, critical specific angular momentum change j s , crit that separates contracting from expanding cases, which depends on the binary mass ratio and on the relative accretion onto the two stars. Using finite and infinite disc models, we show that the inferred binary evolution is very similar for both setups, and we confirm that j s can be measured accurately with cylindrical simulations that do not include the central binary. However, to obtain the relative accretion onto the stars for non-equal mass binaries, simulations that cover the whole domain including the binary are required. We find that for thick discs with aspect ratio h = 0 . 1, the binaries expand for all viscosities, while discs with h = 0 . 05 lead to an expansion only for higher viscosities with α exceeding ∼ 0 . 005. Overall, the regime of binary expansion extends to a much wider parameter space than previously anticipated, but for thin, low-viscosity discs, the orbits shrink.

Fluid phase equilibria for the CO2 + 2,3-dimethylbutane binary system from 291.9 K to 373.1 K

Abstract: The phase behavior of the CO2 (1) + 2,3-dimethylbutane (2) binary mixture has been experimentally studied between 293 and 373 K. Saturation pressures, ranging from 14.0 to 112.2 bar, were visually measured using a high-pressure cell at carbon dioxide mole fractions between 0.20 and 0.93. 78 experimental points have been measured: 67 bubble points and 11 dew points. Experimental results reveal that the vapor-liquid critical locus is a continuous curve between the two pure compounds, meaning that the studied binary system exhibits a type I or II phase behavior in the classification scheme of Van Konynenburg and Scott. The experimental data can be very satisfactorily represented by the Peng-Robinson equation of state with mixing rules that embed a temperature-dependent binary interaction parameter.

A Single-lined Spectroscopic Binary Companion to an Active and Deep Contact Binary in a Quintuple Stellar System

Abstract: V410 Aur is a known deep and low-mass-ratio contact binary with a spectroscopically tertiary component and a visual companion. However, the physical and orbital properties of the tertiary are unknown. We constructed (O − C) curve with 117 new eclipse times and those collected from the literature, which shows a cyclical variation with a period of 25.44 (±1.17) yr and a projected semimajor axis of 0.0348 (±0.0021) days while it undergoes a long-term period decrease at a rate of dP/dt = −1.58 × 10−7daysyr−1. The cyclical variation is analyzed for the light-travel time effect. The minimum mass of the third body is determined as 1.39 (±0.13) M ⊙ that is much larger than the inferred value (0.97 M ⊙) of spectroscopic investigation, which indicates that the spectroscopically tertiary is a single-lined spectroscopic binary with an unseen component. The maximum orbital semimajor axis 6.19 (±0.67) au of the third body is determined. Gaia detected a visual companion to V410 Aur at practically the same distance from the Sun nicely confirming the physical bond. These results reveal that V410 Aur contains a single-lined spectroscopic binary with a visual companion in a quintuple stellar system. TESS photometric solutions confirmed that V410 Aur is a deep overcontact binary with a fill-out factor of 73.83(88)% where the additional light contribution is about 24.80(18)%. The continuous variations of light curves are explained by the evolution of a dark spot on the more massive component. The parabolic variation in the (O − C) curve may be caused by the mass transfer from the massive component to the less massive one in the deep overcontact binary.

The eclipsing binary systems with δ Scuti component – II. AB Cas

Abstract: We present a complex study of the eclipsing binary system, AB Cas. The analysis of the whole TESS light curve, corrected for the binary effects, reveals 112 significant frequency peaks with 17 independent signals. The dominant frequency f1 = 17.1564 d−1 is a radial fundamental mode. The O − C analysis of the times of light minima from over 92 years leads to a conclusion that due to the ongoing mass transfer the system exhibits a change of the orbital period at a rate of 0.03 s per year. In order to find evolutionary models describing the current stage of AB Cas, we perform binary evolution computations. Our results show the AB Cas system as a product of the rapid non-conservative mass transfer with about 5-26% of transferred mass lost from the system. This process heavily affected the orbital characteristics of this binary and its components in the past. In fact, this system closely resemble the formation scenarios of EL CVn type binaries. For the first time, we demonstrate the effect of binary evolution on radial pulsations and determine the lines of constant frequency on the HR diagram. From the binary and seismic modelling, we obtain constraints on various parameters. In particular, we constrain the overshooting parameter, fov ∈ [0.010, 0.018], the mixing-length parameter, αMLT ∈ [1.2, 1.5] and the age, t ∈ [2.3, 3.4] Gyr.

Binary Ti–Fe system. Part II: Modelling of pressure-dependent phase stabilities

Abstract: Based on the experimental and calculated data from literature, the thermodynamic assessment of the binary Ti–Fe system under hydrostatic pressure was performed. The pressure-independent part of the Gibbs energy was modelled using the heat capacity data. The description of the pressure-dependent part of the Gibbs energy was based on the molar volume, thermal expansion and bulk modulus data, and on their pressure derivatives. Using the Murnaghan equation of state, the binary phase stabilities in the Ti–Fe system were assessed to reproduce the experimental results in the pressure range between 2.3 and 2.7 GPa. The thermodynamic functions were converted into the parameters of a phenomenological pressure model, which is implemented in the Thermo-Calc software. The reliability of the assessment is illustrated on the unary systems Ti and Fe containing high-temperature and high-pressure phases, and on the binary Ti–Fe system containing intermetallic phases TiFe and TiFe2 in addition to the terminal solid solutions. It is shown that the calculation of the T0 lines can help in understanding the formation of α′-Ti(Fe) martensite and the high-pressure phase ω-Ti and its metastability at atmospheric pressure.

Pore volume and surface diffusion model (PVSDM) applied for single and binary dye adsorption systems

Abstract: The PVSDM model was used for single and binary dye adsorption systems. This model is commonly used for adsorption in single systems, but this is the first time used in a binary mixture of dyes in the literature. To that end, a new adsorbent derived from Bauhinia forficata waste was created and described for eventual use in the treatment of a dye combination (methylene blue and crystal violet). The single and binary isotherms revealed that increasing the temperature decreases the methylene blue adsorption capacity while increasing the crystal violet adsorption capacity. The Langmuir and extended Langmuir models described the single and binary systems, respectively. Maximum adsorption capacities of 229.13 mg g−1 at 298 K for methylene blue and 324.12 mg g−1 at 328 K for crystal violet were obtained. The thermodynamic parameters showed that the adsorption process for both dyes is spontaneous, being exothermic for the methylene blue and endothermic for the crystal violet. Similar decay curves for the single and binary systems were observed. The PVSDM was able to describe both single and binary adsorption systems. The external mass transfer and the surface diffusion change according to the initial dye concentration and the system type (single or binary).

Fluid phase equilibria for the CO2 + 2,3-dimethylbutane binary system from 291.9 K to 373.1 K

Abstract: The phase behavior of the CO2 (1) + 2,3-dimethylbutane (2) binary mixture has been experimentally studied between 293 and 373 K. Saturation pressures, ranging from 14.0 to 112.2 bar, were visually measured using a high-pressure cell at carbon dioxide mole fractions between 0.20 and 0.93. 78 experimental points have been measured: 67 bubble points and 11 dew points. Experimental results reveal that the vapor-liquid critical locus is a continuous curve between the two pure compounds, meaning that the studied binary system exhibits a type I or II phase behavior in the classification scheme of Van Konynenburg and Scott. The experimental data can be very satisfactorily represented by the Peng-Robinson equation of state with mixing rules that embed a temperature-dependent binary interaction parameter.

New mathematical modeling of temperature-based properties of ionic liquids mixture: Comparison between semi-empirical equation and equation of state

Abstract: Ionic liquids are a significant type of organic salts with attractive and superior physicochemical features for employing in a number of chemical processes. Ionic liquids include one large and asymmetric cationic or anionic functional group. The properties of cationic functional group are almost similar and it is main motivation of this study. In the present investigation, we extended various semi-empirical correlations to predict some temperature-based properties of ionic liquids mixture (IL-mixture). These properties are density, viscosity, surface tension and bubble point pressure. In the case of IL-mixture density, modified Rackett equation and Taylor equation with three scenarios, modified Gardas and Coutinho equation were considered and the obtained results were compared with Peng-Robinson equation of state (EoS), Patel-Teja EoS and perturbed-chain statistical associating fluid theory EoS. In the case of IL-mixture viscosity, two types of activation energy concept models were used and also, Lee-Kesler method and modified Brock and Bird were applied to predict IL-mixture bubble point pressure and IL-mixture surface tension, respectively. A used dataset was collected from reliable literature including 2731 data points of bubble pressure (23 binary system), 4643 data points of density (102 binary system), 1011 data points of viscosity (32 binary system) and 391 data points of surface tension (16 binary system). These data relevant to 12 cation-family and 36 solvents. The all of the data was haphazardly separated in two subsets of train and test with a computer program. The obtained results indicated all used semi-empirical correlations gives the best match with corresponding experimental data and the values of statistical parameters demonstrated this hypothesis.

Search for a Black Hole Binary in Gaia DR3 Astrometric Binary Stars with Spectroscopic Data

Abstract: We report the discovery of a candidate binary system consisting of a black hole (BH) and a red giant branch star in Gaia DR3. This binary system was discovered from 64,108 binary solutions for which both astrometric and spectroscopic data are available. For this system, the astrometric and spectroscopic solutions are consistent with each other, making this system a confident candidate of a BH binary. The primary (visible) star in this system, Gaia DR3 5870569352746779008, is a red giant branch star whose mass is quite uncertain. Fortunately, despite the uncertainty of the primary’s mass, we can estimate the mass of the secondary (dark) object in this system to be >5.68 M ⊙ with a probability of 99%, based on the orbital parameters. The mass of the secondary object is much larger than the maximum neutron star mass (∼2.0 M ⊙), which indicates that the secondary object is likely a BH. We argue that, if this dark object is not a BH, this system must be a more exotic system, in which the primary red giant branch star orbits around a quadruple star system (or a higher-order multiple-star system) whose total mass is more than 5.68 M ⊙. If this is a genuine BH binary, this has the longest period (1352.22 ± 45.81 days) among those discovered so far. As our conclusion entirely relies on Gaia DR3 data, independent confirmation with follow-up observations (e.g., long-term time-series spectra) is desired.

Testing the presence of a dormant black hole inside HR 6819

Abstract: Context. HR 6819 was recently reported to be a triple system with a non-accreting black hole (BH). The inner binary system was defined as a B3 III type star (a 5 − 7 M ⊙ star estimated to be at the end of its main sequence) and a dormant BH (> 4.2 M ⊙ ). The period of the inner binary was estimated to be ∼40 days with an eccentricity in the range 0.02 − 0.04. As the inner binary is not resolved, the third component may actually just be spatially coinciding with the inner binary. Aims. In this study we test whether the system’s inner binary can be reconstructed using the isolated binary evolution in the Galactic field or through the dynamical evolution within globular star clusters. Our goal is to understand the formation of the HR 6819 inner binary. Methods. To simulate the inner binary evolution we assumed that the influence of the third body on the inner binary is negligible. We created synthetic populations of BH-main sequence binaries for the Galactic disc and the Galactic globular clusters to compare to the reported parameters of the HR 6819 inner binary. We have adopted very optimistic input physics, in terms of common envelope evolution and BH formation, for the formation of binaries similar to the reported inner HR 6819 binary. Results. Despite our optimistic assumptions we cannot form systems like the inner HR 6819 binary in globular clusters. Even with our extreme assumptions, the formation of an HR 6819-like binary in the Galactic field population is not expected. Conclusions. We argue that if a dormant BH actually exists in the reported configuration inside HR 6819, its presence cannot easily be explained by our models based on isolated and dynamical binary evolution.

Adsorption removal of crystal violet in single and binary systems onto low-cost iron oxide nanoparticles coated clinoptilolite powders/granules

Abstract: Abstract Novel magnetic adsorbents of Clinoptilolite/Fe 3 O 4 (Clin/Fe 3 O 4 ) nanocomposite powders and Alginate/Clinoptilolite/Fe 3 O 4 (Alg/Clin/Fe 3 O 4 ) nanocomposite granules were synthesized to efficient removal of the cationic crystal violet (CV) dye in single and CV/methylene blue (MB) binary systems. The resulting adsorbents were characterized by FTIR, XRD, SEM, EDX, dot mapping, and BET analysis. Adsorption tests showed that Clin/Fe 3 O 4 and Alg/Clin/Fe 3 O 4 presented an excellent high affinity to CV removal as 94.32% and 92.35%, respectively in the single system and as 84.19% and 80.23%, respectively in the binary system. Based on the findings, pH was the most effective variable in the elimination process and the highest yield achieved at pH 8 for both adsorbents. The equilibrium data followed the Langmuir model (R 2 > 0.9) based which the maximum adsorption capacity (q max ) using Clin/Fe 3 O 4 and Alg/Clin/Fe 3 O 4 was determined as 44.662 mg/g and 16.528 mg/g, respectively in the single system and it was computed to be 15.797 mg/g and 11.476 mg/g, respectively in the binary system. The kinetic data fitted well to the pseudo-second-order model in both systems. The adsorption process was exothermic and thermodynamically spontaneous. Moreover, the adsorbents showed excellent recycling ability over the desorption tests, thus leading to a promising and green-based adsorbents for the removal of dyes. The electrical conductivity (EC) of MB, CV, and CV/MB solutions and also a real wastewater sampled from a dyeing unit were measured before and after treatment and the results showed that the EC of all samples was reduced.

Co-Removal Effect and Mechanism of Cr(VI) and Cd(II) by Biochar-Supported Sulfide-Modified Nanoscale Zero-Valent Iron in a Binary System

Abstract: This study aimed to explore the co-removal effect and mechanism of Cr(VI) and Cd(II) with an optimized synthetic material. The toxicity and accumulation characteristics of Cr(VI) and Cd(II) encountered in wastewater treatment areas present significant challenges. In this work, a rational assembly of sulfide-modified nanoscale zero-valent iron (SnZVI) was introduced into a biochar (BC), and a Cr(VI)–Cd(II) binary system adsorbent with high efficiency was synthesized. When the preparation temperature of the BC was 600 °C, the molar ratio of S/Fe was 0.3, the mass ratio of BC/SnZVI was 1, and the best adsorption capacities of BC-SnZVI for Cr(VI) and Cd(II) in the binary system were 58.87 mg/g and 32.55 mg/g, respectively. In addition, the adsorption mechanism of BC-SnZVI on the Cr(VI)-Cd(II) binary system was revealed in depth by co-removal experiments, indicating that the coexistence of Cd(II) could promote the removal of Cr(VI) by 9.20%, while the coexistence of Cr(VI) could inhibit the removal of Cd(II) by 43.47%. This work provides a new pathway for the adsorption of Cr(VI) and Cd(II) in binary systems, suggesting that BC-SnZVI shows great potential for the co-removal of Cr(VI) and Cd(II) in wastewater.

Refined physical properties of the hd327083 binary system

Abstract: HD327083 is a member of a small group of supergiants exhibiting the B[e] phenomenon. It was found to be a binary system with an early-B and an early-F supergiant components. However the fundamental and orbital parameters of the system were not accurately known. We determined a new set of the system parameters that include the orbital period and the components’ masses using a combination of photometric and spectroscopic data. A new orbital period of 107.7 days was found from both the spectral line positional variations and the visual light curve. Absorption lines of the cool component show a radial velocity semi-amplitude of 48.3 kms −1 , similar to that of emission lines that originate around the hot component. The system shows partial eclipses. We estimated the components’ masses to be nearly equal and close to 6-8 M ? . The masses turned out to be smaller then the evolutionary masses that may be a consequence of a recent mass-transfer.

Dynamically Forming Extremely Low-mass White Dwarf Binaries in Wide Orbits

Abstract: The detection of a 0.2 M ⊙ extremely low-mass white dwarf (EW) in a wide orbit (P orb ≈ 450 days) with a 1.1 M ⊙ main-sequence companion, KIC 8145411, challenges our current understanding of how EWs form. The traditional channel for EW formation, via mass transfer from the EW’s progenitor, is expected to form EW binaries in tight orbits. Indeed, the majority of known EWs are found in tight binaries with a median P orb ≈ 5.4 hr. Using numerical scattering experiments, we find that binary–binary strong encounters in star clusters can sufficiently widen the orbit of a typical EW binary, to explain the observed wide orbit of the KIC 8145411 system. The P orb distribution for EW binaries produced through binary–binary encounters is bimodal: one mode corresponds to the initial orbital period of the EW binary, while the other is near P orb ∼ few 102 days, similar to the orbital period of the KIC 8145411 system. We find that the production of wide EW binaries that are also ejected from the cluster peaks at a star cluster mass of ∼105 M ⊙ with a rate of ∼10−3 Gyr−1. Assuming that 50% of all stars form in star clusters and an initial cluster mass function ∝m −2, we estimate a galactic formation rate of ∼4.16 × 103 Gyr−1 for wide EW binaries.

Vapor–Liquid Equilibrium for the Binary System of 2-Phenylethanol + 2-Ethylphenol at 50.0, 20.0, and 10.5 kPa

Abstract: The vapor–liquid equilibrium (VLE) data for binary systems 2-PE and 2-EP were measured at 50.0, 20.0, and 10.5 kPa using a modified Rose equilibrium still. The Redlich–Kister area test and Fredenslund point test were applied to test the thermodynamic consistency of the VLE data, respectively. In addition, experimental data were successfully matched using nonrandom two-liquid (NRTL), Wilson, and Universal Quasi-Chemical (UNIQUAC) activity coefficient models. Binary interaction parameters (BIPs) corresponding to three models were obtained by maximum likelihood target function regression. This paper would help the distillation design of 2-phenylethanol and 2-ethylphenol in industrial applications.