标题： 基于APOGEE光谱的弥漫星际带的数据驱动发现 显示英文标题

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

摘要： 基于数据驱动的恒星光谱模型是有用的研究非恒星信息的工具，例如由星际介质引起的弥散星际谱带（DIBs）。 利用来自APOGEE DR16数据集的$\sim 17000$红团簇星的$\sim 55000$条光谱，我们创建了归一化连续通量作为恒星参数（$T_{eff}$、$\log g$、[Fe/H]、[$\alpha$/Fe]和Age）函数的二阶多项式模型。 模型和数据在APOGEE波长范围内在不确定性范围内表现出良好的一致性，尽管许多区域显示出非恒星静止帧的残差。 我们表明，这些残差特征中的许多特征——平均而言在恒星流量上的平均极值为$\sim3\%$——可以归因于未完全去除的地表大气光谱线以及星际介质（ISM）中的DIBs。 在消除了地球天空中大部分剩余污染后，我们识别出84个在未受红化视线中未观察到的吸收特征，这些特征有$<50\%$的概率是噪声伪影——其中25个特征有$<5\%$的概率是噪声伪影——其中包括APOGEE波长范围内先前已知的所有10个DIBs。 由于许多这些特征出现在APOGEE用于测量化学丰度的波长窗口中，因此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。 对这些特征的准确表征将有利于银河系星际介质科学以及SDSS-V正在进行的Milky Way Mapper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 interstellar material. Using $\sim 55000$ spectra of $\sim 17000$ 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 absorption features not seen in unreddened sightlights that have $<50\%$ probability of being noise artifacts -- with 25 of these features having $<5\%$ probability of being noise artifacts -- 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.