SPICY: The Spitzer/IRAC Candidate YSO Catalog

We present ~120,000 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 datasets to take full advantage of IRAC’s spatial resolution and sensitivity in the mid-infrared ∼3–9 μm range. 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.