论文标题
蓝色水平分支星星的颜色障碍关系的SDSS-GAIA观点
The SDSS-Gaia View of the Color-Magnitude Relation for Blue Horizontal-branch Stars
论文作者
论文摘要
我们提供了从Sloan Digital Sky Survey及其相关的Sloan Extension从光度和光谱数据中选择的蓝色水平分支（BHB）星的最新样本，以进行银河系理解和探索（SEGUE）。有了这些数据，我们在颜色颜色空间中选择了A型星的候选物，然后实现了混合物建模技术，以根据其表面重力值（$ \ log \ rm {g} $）估计的segue segue stellar stellar stellar stellar stellar parameter pometer pimeter pimeter pipereare估算了BHB和Main-序列/蓝色 - straggler恒星。我们强大的方法使我们能够将每个恒星的个人概率归因于BHB阶段。因此，与以前采用简单$ \ log \ rm {g} $ cuts的SEGUE BHB选择相比，我们的方法是有利的。我们还基于银河球状簇的更新距离，对这些恒星的颜色质量关系进行了两次校准，以估计具有$（g-r）_0 $和$（u-r）_0 _0 $颜色的绝对幅度。
We present an updated sample of blue horizontal-branch (BHB) stars selected from the photometric and spectroscopic data from Sloan Digital Sky Survey and its associated project Sloan Extension for Galactic Understanding and Exploration (SEGUE). With this data, we selected candidates for A-type stars in the color-color space and then a mixture modeling technique was implemented in order to distinguish between BHB and main-sequence/blue-straggler stars based on their surface gravity values ($\log \rm{g}$) estimated by the SEGUE Stellar Parameter Pipeline. Our robust approach allows us to attribute individual probabilities of each star truly being in the BHB stage. Hence, our method is advantageous in comparison to previous SEGUE BHB selections that adopted simple $\log \rm{g}$ cuts. We also revisit the color-magnitude relation for these stars and propose two calibrations, based on updated distances for Galactic globular clusters, to estimate absolute magnitudes with $(g-r)_0$ and $(u-r)_0$ colors.
