标题： 基于APOGEE光谱的数据驱动发现弥散星际带 显示英文标题

标题： Data-driven Discovery of Diffuse Interstellar Bands with APOGEE Spectra

摘要： 数据驱动的恒星光谱模型是研究非恒星信息的有用工具，例如由中间气体和尘埃引起的弥散星际带（DIBs）。 使用来自APOGEE DR16数据集的$\sim55000$光谱和$\sim17000$红团簇恒星的数据，我们创建了连续谱归一化通量作为恒星参数（$T_{eff}$、$\log g$、[Fe/H]、[$\alpha$/Fe]和年龄）的二阶多项式模型。 在APOGEE波长范围内，模型和数据在不确定度内表现出良好的一致性，尽管许多区域显示出不在恒星静止框架中的残差。 我们表明，这些残差特征——平均在恒星通量中达到$\sim3\%$的极值——可以归因于未完全去除的地球大气光谱线和星际介质（ISM）的DIBs。 在去除大部分来自地球天空的剩余污染后，我们识别出84个（25个）吸收特征，其被偶然解释的概率低于50%（5%），包括所有在APOGEE波长范围内的10个已知DIBs。 由于这些特征中的许多出现在APOGEE用于测量化学丰度的波长窗口中，对这种非恒星污染的表征和去除是达到化学标记实验所需精度的重要步骤。 对这些特征的正确表征将有助于银河系ISM科学以及目前正在进行的SDSS-V银河系映射器项目，该项目依赖于APOGEE光谱仪。 显示英文摘要

摘要： Data-driven models of stellar spectra are useful tools to study non-stellar information, such as the Diffuse Interstellar Bands (DIBs) caused by intervening gas and dust. Using $\sim55000$ spectra of $\sim17000$ red clump stars from the APOGEE DR16 dataset, we create 2nd order polynomial models of the continuum-normalized flux as a function of stellar parameters ($T_{eff}$, $\log g$, [Fe/H], [$\alpha$/Fe], and age). The model and data show good agreement within uncertainties across the APOGEE wavelength range, although many regions reveal residuals that are not in the stellar rest-frame. We show that many of these residual features -- having average extrema at the level of $\sim3\%$ in stellar flux on average -- can be attributed to incompletely-removed spectral lines from the Earth's atmosphere and DIBs from the interstellar medium (ISM). After removing most of the remaining contamination from the Earth's sky, we identify 84 (25) absorption features that have less than a 50% (5%) probability of being explained by chance alone, including all 10 previously-known DIBs in the APOGEE wavelength range. Because many of these features occur in the wavelength windows that APOGEE uses to measure chemical abundances, characterization and removal of this non-stellar contamination is an important step in reaching the precision required for chemical tagging experiments. Proper characterization of these features will benefit Galactic ISM science and the currently-ongoing Milky Way Mapper program of SDSS-V, which relies on the APOGEE spectrograph.