arXiv 2102.102102021-02-20astro-ph.SRastro-ph.GAastro-ph.IM

盖亚高自行星的贝叶斯交叉匹配DR2和$\sim$ 170万K和M矮星的光度金属丰度

Bayesian Cross-Matching of High Proper Motion Stars in Gaia DR2 and Photometric Metallicities for $\sim$1.7 million K and M Dwarfs

Ilija Medan, Sébastien Lépine, Zachary Hartman

备注：: 51 pages, 23 figures
DOI：: 10.3847/1538-3881/abe878

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摘要：

我们提出了一种贝叶斯方法交叉匹配5，827，988高自行盖亚源（$μ>40 \ mas \ yr^{-1}$）的各种测光调查：2 MASS，AllWISE，GALEX，RAVE，SDSS和泛星。为了有效地关联这些对象的目录，我们开发了一种技术，比较多维分布的所有来源在每个盖亚恒星附近的参考分布的随机场星通过提取所有来源在天空中的位移2 $^\prime$的区域。这种偏移保留了局部场恒星密度和星等分布，使我们能够表征机会排列的频率。贝叶斯概率为$>$ 95%的结果目录的匹配率略高于大多数目录的当前内部Gaia DR 2匹配。然而，Pan-STARRS发现了显著的改善，其中Pan-STARRS足迹内的样品的$\sim$ 99.8%被回收，而Gaia DR 2中的低$\sim$为20.8%。利用这些结果，我们训练高斯过程回归校准两个光度金属丰度关系。对于$3500<T_{eff}<5280$ K的矮星，我们使用来自APOGEE和Hejazi等人（2020）的4，378颗恒星的金属丰度值来校准关系，产生的结果$1σ$精度为0.12 dex，系统误差很少。然后，我们间接推断4,018颗恒星的金属丰度与$2850<T_{eff}<3500$ K，这是广泛的同伴的原色的金属丰度估计与我们的第一个回归，产生的关系与$1σ$精度为0.21 dex和显着的系统误差。需要进行额外的工作，以更好地从该样本中删除未解析的二进制文件，从而减少这些系统误差。

英文摘要：

We present a Bayesian method to cross-match 5,827,988 high proper motion Gaia sources ($μ>40 \ mas \ yr^{-1}$) to various photometric surveys: 2MASS, AllWISE, GALEX, RAVE, SDSS and Pan-STARRS. To efficiently associate these objects across catalogs, we develop a technique that compares the multidimensional distribution of all sources in the vicinity of each Gaia star to a reference distribution of random field stars obtained by extracting all sources in a region on the sky displaced 2$^\prime$. This offset preserves the local field stellar density and magnitude distribution allowing us to characterize the frequency of chance alignments. The resulting catalog with Bayesian probabilities $>$95% has a marginally higher match rate than current internal Gaia DR2 matches for most catalogs. However, a significant improvement is found with Pan-STARRS, where $\sim$99.8% of the sample within the Pan-STARRS footprint is recovered, as compared to a low $\sim$20.8% in Gaia DR2. Using these results, we train a Gaussian Process Regressor to calibrate two photometric metallicity relationships. For dwarfs of $3500<T_{eff}<5280$ K, we use metallicity values of 4,378 stars from APOGEE and Hejazi et al. (2020) to calibrate the relationship, producing results with a $1σ$ precision of 0.12 dex and few systematic errors. We then indirectly infer the metallicity of 4,018 stars with $2850<T_{eff}<3500$ K, that are wide companions of primaries whose metallicities are estimated with our first regressor, to produce a relationship with a $1σ$ precision of 0.21 dex and significant systematic errors. Additional work is needed to better remove unresolved binaries from this sample to reduce these systematic errors.

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