论文标题
Draco C1共生二进制的几何形状
Geometry of the Draco C1 Symbiotic Binary
论文作者
论文摘要
Draco C1是一种已知的共生二进制星系，由碳红色巨人和热，紧凑的伴侣组成，可能是白矮人 - 属于Draco Dwarf球形星系。从Apache Point天文台银河系演化实验（Apogee-2）进行的近红外光谱观测（Sloan数字天空调查IV的一部分）中，我们为凉爽，巨大的成分提供了更新的恒星参数，并限制了热，紧凑型伴侣的温度和质量。基于径向速度数据的几个时期或相对较短的基线光度观测值，该系统周期性的先前测量仅足以在轨道周期（$ p> 300美元$天）放置下限。我们首次报告了二进制系统的精确轨道参数：横跨观测基线超过3年的43个径向速度测量值，我们绝对地得出了系统周期为$ 1220.0^{+3.7} _ { - 3.5} _ { - 3.5} $ $天。基于新派生的轨道周期和系统的分离，以及对红色巨星半径的估计，我们发现热伴侣必须从其进化伴侣的密集风中吸收物质。
Draco C1 is a known symbiotic binary star system composed of a carbon red giant and a hot, compact companion -- likely a white dwarf -- belonging to the Draco dwarf spheroidal galaxy. From near-infrared spectroscopic observations taken by the Apache Point Observatory Galactic Evolution Experiment (APOGEE-2), part of Sloan Digital Sky Survey IV, we provide updated stellar parameters for the cool, giant component, and constrain the temperature and mass of the hot, compact companion. Prior measurements of the periodicity of the system, based on only a few epochs of radial velocity data or relatively short baseline photometric observations, were sufficient only to place lower limits on the orbital period ($P > 300$ days). For the first time, we report precise orbital parameters for the binary system: With 43 radial velocity measurements from APOGEE spanning an observational baseline of more than 3 years, we definitively derive the period of the system to be $1220.0^{+3.7}_{-3.5}$ days. Based on the newly derived orbital period and separation of the system, together with estimates of the radius of the red giant star, we find that the hot companion must be accreting matter from the dense wind of its evolved companion.
