Eclipsing Binary Solutions in Physical Units and Direct Distance Estimation
Eclipsing Binary Solutions in Physical Units and Direct Distance Estimation
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DOI：
10.1086/523634
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发表时间：
2008
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影响因子：
--
通讯作者：
R. Wilson
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文献类型：
--
作者：
R. Wilson
研究了从标准通量单位而不是传统的任意单位的食二元光曲线中提取距离和温度的机会。好处包括：(1)距离成为一个具有标准误差的普通解参数，(2)在有利的情况下，两颗恒星的温度都可以得到，以及(3)与分离良好的双星相比，半连接和过接触双星的距离精度没有损失。通量定标只进入观测值，而理论通量自然以标准单位表示，因此理论和观测的对峙是直接的，不需要基于色温关系的半经验量。这种被称为直接距离估计(DDE)的整体过程还通过避免单独的距离估计步骤来节省时间和精力，并且应该导致对大量日食双星(EB)的常规距离测量。讨论将DDE与传统的EB距离估计进行了比较，后者在大多数出版物中仅限于完全分离的二进制文件。严格处理了受潮汐和辐射影响的光谱或色温的方位依赖关系。通过几种模拟验证了温度-距离定理，该定理规定了从电子束光和速度曲线中寻找温度和距离的要求。给出了过接触二进制AW UMA和半附着式二进制RZ数控系统的示例性解决方案，并讨论了温度和距离的结果。尽管AW UMA有许多观测和结构上的奇怪之处，但它的DDE和依巴谷的距离是一致的。RZ Cnc的六个DDE距离，以几种方式和三个光度波段完成，完全落在其依巴谷距离的1σ范围内。讨论了校准误差、参数值和拟合误差之间的相互作用，以及适当的权重。
Opportunities for extraction of distances and temperatures from eclipsing binary light curves that are in standard flux units, as opposed to traditional arbitrary units, are examined. Benefits include (1) distance becomes an ordinary solution parameter with a standard error, (2) temperatures of both stars may be derivable in favorable circumstances, and (3) semidetached and overcontact binaries suffer no loss of distance accuracy, vis-à-vis well-detached binaries. Flux calibrations enter only for the observations, while theoretical fluxes are naturally in standard units, so confrontation of theory and observation is direct, and semiempirical quantities based on color-temperature relations are not needed. The monolithic process, called direct distance estimation (DDE), also saves time and effort by avoiding separate distance estimation steps and should lead to routine distance measurements for large numbers of eclipsing binaries (EBs). Discussions compare DDE with traditional EB distance estimation, which has been restricted to well detached binaries in most publications. Aspect dependence of spectroscopic or color temperature, as affected by tides and irradiation, is treated rigorously. A temperature-distance theorem that specifies requirements for finding temperatures and distance from EB light and velocity curves is checked by several kinds of simulations. Demonstration solutions are carried out for the overcontact binary AW UMa and the semidetached binary RZ Cnc, with discussions of temperature and distance results. Although AW UMa has many observational and structural oddities, its DDE and Hipparcos distances agree. Six DDE distances for RZ Cnc, done in several ways and for three photometric bands, fall well within the 1 σ range of its Hipparcos distance. Interactions among calibrative errors, parameter values, and fitting discrepancies are discussed, as is proper weighting.