Optical emission lines are used to categorize galaxies into three groups according to their dominant central radiation source: active galactic nuclei, star formation, or low-ionization (nuclear) emission regions [LI(N)ERs] that may trace ionizing radiation from older stellar populations. Using the Wisconsin H-Alpha Mapper, we detect optical line emission in low-extinction windows within eight degrees of Galactic Center. The emission is associated with the 1.5-kiloparsec-radius “Tilted Disk” of neutral gas. We modify a model of this disk and find that the hydrogen gas observed is at least 48% ionized. The ratio [NII] λ6584 angstroms/Hα λ6563 angstroms increases from 0.3 to 2.5 with Galactocentric radius; [OIII] λ5007 angstroms and Hβ λ4861 angstroms are also sometimes detected. The line ratios for most Tilted Disk sightlines are characteristic of LI(N)ER galaxies.

光发射线用于根据星系的主要中心辐射源将星系分为三组：活动星系核、恒星形成或低电离（核）发射区域 [LI(N)ER]，这些区域可以追踪来自较老恒星的电离辐射人口。使用威斯康星州 H-Alpha 测绘仪，我们在银河系中心 8 度范围内的低消光窗口中检测到光线发射。发射与 1.5 千秒差距半径的中性气体“倾斜圆盘”有关。我们修改了该圆盘的模型，发现观察到的氢气至少有 48% 被电离。随着银河系中心半径的增加，[NII] λ6584 埃/Hα λ6563 埃的比率从 0.3 增加到 2.5； [OIII] 有时也会检测到 λ5007 埃和 Hβ λ4861 埃。大多数倾斜盘视线的线比是 LI(N)ER 星系的特征。