We present ∼120,000 Spitzer/IRAC candidate young stellar objects (YSOs) based on surveys of the Galactic midplane between ℓ ∼ 255 and 110, including the GLIMPSE I, II, and 3D, Vela-Carina, Cygnus X, and SMOG surveys (613 square degrees), augmented by near-infrared catalogs. We employed a classification scheme that uses the flexibility of a tailored statistical learning method and curated YSO data sets to take full advantage of Spitzer’s spatial resolution and sensitivity in the mid-infrared ∼3–9 μm range. Multiwavelength color/magnitude distributions provide intuition about how the classifier separates YSOs from other red IRAC sources and validate that the sample is consistent with expectations for disk/envelope-bearing pre–main-sequence stars. We also identify areas of IRAC color space associated with objects with strong silicate absorption or polycyclic aromatic hydrocarbon emission. Spatial distributions and variability properties help corroborate the youthful nature of our sample. Most of the candidates are in regions with mid-IR nebulosity, associated with star-forming clouds, but others appear distributed in the field. Using Gaia DR2 distance estimates, we find groups of YSO candidates associated with the Local Arm, the Sagittarius–Carina Arm, and the Scutum–Centaurus Arm. Candidate YSOs visible to the Zwicky Transient Facility tend to exhibit higher variability amplitudes than randomly selected field stars of the same magnitude, with many high-amplitude variables having light-curve morphologies characteristic of YSOs. Given that no current or planned instruments will significantly exceed IRAC’s spatial resolution while possessing its wide-area mapping capabilities, Spitzer-based catalogs such as ours will remain the main resources for mid-infrared YSOs in the Galactic midplane for the near future.

我们基于对ℓ ∼ 255 和 110之间的银河中平面的调查，包括 GLIMPSE I、II 和 3D、船帆座、天鹅座 X 和 SMOG 调查（613平方度），由近红外目录增强。我们采用了一种分类方案，该方案利用定制统计学习方法的灵活性和精选的 YSO 数据集，以充分利用 Spitzer 在中红外 ∼3-9 μ的空间分辨率和灵敏度米范围。多波长颜色/星等分布提供了关于分类器如何将 YSOs 与其他红色 IRAC 源分开并验证样本与带有盘/包络前主序星的预期一致的直觉。我们还确定了与具有强硅酸盐吸收或多环芳烃发射的物体相关的 IRAC 颜色空间区域。空间分布和可变性特性有助于证实我们样本的年轻特性。大多数候选者位于具有中红外星云的区域，与恒星形成云相关，但其他人似乎分布在现场。使用 Gaia DR2 距离估计，我们找到了与 Local Arm、Sagittarius-Carina Arm 和 Scutum-Centaurus Arm 相关的 YSO 候选组。兹威基瞬变设施可见的候选 YSO 往往比随机选择的相同星等的场星表现出更高的可变振幅，许多高振幅变量具有 YSO 的光曲线形态特征。鉴于目前或计划中的任何仪器都不会在拥有广域测绘能力的同时显着超过 IRAC 的空间分辨率，在不久的将来，像我们这样的基于斯皮策的目录仍将是银河中平面中红外 YSO 的主要资源。