论文标题
部分可观测时空混沌系统的无模型预测
Metallicity of Galactic RR Lyrae from Optical and Infrared Light Curves: II. Period-Fourier-Metallicity Relations for First Overtone RR Lyrae
论文作者
论文摘要
We present new period-$ϕ_{31}$-[Fe/H] relations for first overtone RRL stars (RRc), calibrated over a broad range of metallicities ($-2.5 < \textrm{[Fe/H]}< 0.0$) utilizing the largest currently available set of Galactic halo field RRL with homogeneous spectroscopic metallicities.我们的关系是在光学（ASAS-SN $ V $ -BAND）中定义的，并在红外线（明智的$ W1 $和$ W2 $ bands）中定义。我们的$ v $ - 带关系可以在校准器样品的整个金属性范围内复制单个RRC光谱金属，其分散剂为0.30 DEX（比我们在包括非线性术语在内的文献中发现的其他关系小的RMS（RMS）。我们的红外关系在低和中间的金属性范围内具有类似的分散体（$ \ textrm {[Fe/h]} <-0.5 $），但倾向于低估太阳金属性周围的[Fe/H]丰度。我们通过测量雕塑家DSPH的金属性和富含RRC和RRAB恒星的银河球状簇样品来测试我们的关系。我们在每个集群中获得的RRL样品的平均金属性在其光谱金属度的$ \ pm 0.08 $ dex之内。这项工作中介绍的红外关系和光学关系将使在光谱测量不可行的条件下得出可靠的光度RRL金属性。例如，在遥远的星系或变红的区域（即将进行的非常大的望远镜和James Webb空间望远镜观察到），或者在大型新RRL样本中，将在大区域时间域中的大型时间域光度测试（例如LSST和Roman Space望远镜）中发现。
We present new period-$ϕ_{31}$-[Fe/H] relations for first overtone RRL stars (RRc), calibrated over a broad range of metallicities ($-2.5 < \textrm{[Fe/H]}< 0.0$) utilizing the largest currently available set of Galactic halo field RRL with homogeneous spectroscopic metallicities. Our relations are defined in the optical (ASAS-SN $V$-band) and, inaugurally, in the infrared (WISE $W1$ and $W2$ bands). Our $V$-band relation can reproduce individual RRc spectroscopic metallicities with a dispersion of 0.30 dex over the entire metallicity range of our calibrator sample (an RMS smaller than what we found for other relations in literature including non-linear terms). Our infrared relation has a similar dispersion in the low and intermediate metallicity range ($\textrm{[Fe/H]} < -0.5$) but tends to underestimate the [Fe/H] abundance around solar metallicity. We tested our relations by measuring both the metallicity of the Sculptor dSph and a sample of Galactic globular clusters, rich in both RRc and RRab stars. The average metallicity we obtain for the combined RRL sample in each cluster is within $\pm 0.08$ dex of their spectroscopic metallicities. The infrared and optical relations presented in this work will enable deriving reliable photometric RRL metallicities in conditions where spectroscopic measurements are not feasible; e.g., in distant galaxies or reddened regions (observed with upcoming Extremely Large Telescopes and the James Webb Space Telescope), or in the large sample of new RRL that will be discovered in large-area time-domain photometric surveys (such as LSST and the Roman space telescope).
