根据稀疏多波段数据对RR天琴座星的机器学习识别：PS1样本
Machine-Learned Identification of RR Lyrae Stars from Sparse, Multi-band Data: the PS1 Sample
摘要：
天琴座RR型星可能是研究星系晕（子）结构和运动学的最佳实用示踪剂。PanSTARRS 1（PS1）$3π$巡天提供了多波段、多历元、精确的测光，但鉴于PS1稀疏、异步的多波段光变曲线（五个波段中的每个波段都有$\lesssim 12$历元，拍摄时间为4.5年），在这个数据集中对RR型天琴座恒星进行可靠的识别是一个挑战。我们提出了一种新的模板拟合技术，使用定义良好的和物理动机的多波段光变曲线的RR天琴座恒星，并证明，我们得到准确的周期估计，精确到2秒的$>80\%$的情况下。我们用光度时间序列中的其他{ \em特征}增强这些光变曲线拟合，并将其提供给逐步更详细的机器学习分类模型。从这些模型中，我们能够选择最宽（天空的$3/4$）和最深（达到120千秒差距）的RR天琴座恒星样本。$\sim 45,000$ RRab星的PS1样本在银河系高纬度地区是纯净的（90%）和完整的（80 kpc时为80%）。它还提供了精确到3%的距离，测量与新导出的周期光度关系的光学/近红外PS1波段。加上自行从{ \em盖亚}和径向速度测量的多目标光谱调查，我们预计PS1样本的RR天琴座恒星成为首要的来源，研究的结构，运动学，和引力势的星系晕。这项研究中提出的技术应该很好地转化为其他稀疏的，多波段的数据集，如那些由暗能量调查和即将到来的大型综合巡天望远镜银河平面子调查。
英文摘要：
RR Lyrae stars may be the best practical tracers of Galactic halo (sub-)structure and kinematics. The PanSTARRS1 (PS1) $3π$ survey offers multi-band, multi-epoch, precise photometry across much of the sky, but a robust identification of RR Lyrae stars in this data set poses a challenge, given PS1's sparse, asynchronous multi-band light curves ($\lesssim 12$ epochs in each of five bands, taken over a 4.5-year period). We present a novel template fitting technique that uses well-defined and physically motivated multi-band light curves of RR Lyrae stars, and demonstrate that we get accurate period estimates, precise to 2~sec in $>80\%$ of cases. We augment these light curve fits with other {\em features} from photometric time-series and provide them to progressively more detailed machine-learned classification models. From these models we are able to select the widest ($3/4$ of the sky) and deepest (reaching 120 kpc) sample of RR Lyrae stars to date. The PS1 sample of $\sim 45,000$ RRab stars is pure (90\%), and complete (80\% at 80 kpc) at high galactic latitudes. It also provides distances precise to 3\%, measured with newly derived period-luminosity relations for optical/near-infrared PS1 bands. With the addition of proper motions from {\em Gaia} and radial velocity measurements from multi-object spectroscopic surveys, we expect the PS1 sample of RR Lyrae stars to become the premier source for studying the structure, kinematics, and the gravitational potential of the Galactic halo. The techniques presented in this study should translate well to other sparse, multi-band data sets, such as those produced by the Dark Energy Survey and the upcoming Large Synoptic Survey Telescope Galactic plane sub-survey.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
