Stellar winds shape the evolution of stars through the loss of mass. In binary systems, they also shape the stars' evolution by modifying the orbit. In this paper, we use hydrodynamic simulations to study the emergence of nearly-isothermal winds from identical-twin binaries. We vary the degree to which model stars fill their Roche lobes and the temperature of the wind. Initialized at rest on the stellar surfaces, winds accelerate away from the binary components through a sonic surface to supersonic outward velocities. In cases where the binary fills its Roche lobe, a shared subsonic region surrounds both components. We find that mass loss rates from close twin-star binaries are enhanced relative to the expectation from two single-object winds. This binary enhancement is best modeled as a function of the ratio of wind velocity to orbital velocity. Similarly, we find that the specific angular momentum with which winds emerge can vary between that of the binary components and that of the outer Lagrange points depending on the ratio of wind velocity to orbital velocity. Given that mass and angular momentum loss can be modeled as simple functions of wind velocity, our results may be broadly applicable to the evolution of close, equal-mass binaries. One particularly important potential application is to massive, close binaries which may be progenitors of binary black hole mergers through the chemically-homogeneous evolution channel.

中文翻译：

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双星双星的流体动力风

恒星风通过质量的损失塑造了恒星的演化。在双星系统中，它们还通过修改轨道来塑造恒星的演化。在本文中，我们使用流体动力学模拟来研究来自同卵双星的近等温风的出现。我们改变模型恒星填充其罗氏瓣的程度和风的温度。在恒星表面静止初始化时，风通过声波表面加速远离二元组件，以超音速向外速度。在双星填充其罗氏瓣的情况下，共享的亚音速区域围绕着两个组件。我们发现，相较于来自两个单天体风的预期，近距离双星双星的质量损失率有所提高。这种二元增强最好建模为风速与轨道速度之比的函数。同样，我们发现风产生的特定角动量可以在二元分量和外拉格朗日点的角动量之间变化，这取决于风速与轨道速度的比率。鉴于质量和角动量损失可以建模为风速的简单函数，我们的结果可能广泛适用于接近等质量双星的演化。一个特别重要的潜在应用是巨大的、紧密的双星，它们可能是通过化学均匀演化通道的双黑洞合并的先驱。我们发现风产生的特定角动量可以在二元分量和外拉格朗日点的角动量之间变化，这取决于风速与轨道速度的比率。鉴于质量和角动量损失可以建模为风速的简单函数，我们的结果可能广泛适用于接近等质量双星的演化。一个特别重要的潜在应用是巨大的、紧密的双星，它们可能是通过化学均匀演化通道的双黑洞合并的祖先。我们发现风产生的特定角动量可以在二元分量和外拉格朗日点的角动量之间变化，这取决于风速与轨道速度的比率。鉴于质量和角动量损失可以建模为风速的简单函数，我们的结果可能广泛适用于接近等质量双星的演化。一个特别重要的潜在应用是巨大的、紧密的双星，它们可能是通过化学均匀演化通道的双黑洞合并的先驱。