Symbiotic Stars in the Apache Point Observatory Galactic Evolution Experiment Survey: The Case of LIN 358 and SMC N73 (LIN 445a)
Symbiotic Stars in the Apache Point Observatory Galactic Evolution Experiment Survey: The Case of LIN 358 and SMC N73 (LIN 445a)
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DOI：
10.3847/1538-4357/ac09ec
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
J. Washington;H. Lewis;B. Anguiano;S. Majewski;S. Chojnowski;V. Smith;K. Stassun;C. Allende Prieto-C.-Al
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文献类型：
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作者：
J. Washington;H. Lewis;B. Anguiano;S. Majewski;S. Chojnowski;V. Smith;K. Stassun;C. Allende Prieto-C.-Al
LIN 358和SMC N73是小麦哲伦星云晕中的两颗共生双星，它们都是由一颗热的白色矮星从一颗冷的巨伴吸积而成。在这项工作中，我们使用光谱能量分布（SED）的组合，这些系统的特征-拟合到现存的光度数据跨越广泛的波长范围（X-射线/紫外线到近红外），详细分析的阿帕奇点天文台银河系演化实验（APOGEE）光谱的巨星，和轨道拟合到高质量的径向速度从APOGEE数据库。利用计算得到的巨组分Roche瓣半径和各系统的质量比，发现LIN 358可能通过风Roche瓣溢出进行质量转移，而SMC N73的吸积机制仍不确定。这项工作提出了这两个系统的第一个轨道特性（SMC N73和LIN 358的周期分别为>270天和>980天）和SMC N73的第一个全球SED拟合。此外，在LIN 358的APOGEE光谱中发现了两年多来跨越17个时期的变异性，这可能表明偏心轨道的产物是一个随时间变化的吸积率。
LIN 358 and SMC N73 are two symbiotic binaries in the halo of the Small Magellanic Cloud, each composed of a hot white dwarf accreting from a cool giant companion. In this work, we characterize these systems using a combination of spectral energy distribution (SED)-fitting to the extant photometric data spanning a broad wavelength range (X-ray/ultraviolet to near-infrared), detailed analysis of the Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectra for the giant stars, and orbit fitting to high quality radial velocities from the APOGEE database. Using the calculated Roche lobe radius for the giant component and the mass ratio for each system, it is found that LIN 358 is likely undergoing mass transfer via wind Roche lobe overflow, while the accretion mechanism for SMC N73 remains uncertain. This work presents the first orbital characterization for both of these systems (yielding periods of >270 and >980 days, respectively, for SMC N73 and LIN 358) and the first global SED fitting for SMC N73. In addition, variability was identified in APOGEE spectra of LIN 358 spanning 17 epochs over two years that may point to a time variable accretion rate as the product of an eccentric orbit.