GaiaUnlimited. Milky Way red clump catalogue

These evolved giants are considered to be standard candles due to their low intrinsic variance in their absolute luminosities, allowing us to estimate their distances with reasonable confidence. We exploit all-sky photometry from the AllWISE mid-infrared survey and the Gaia survey, along with astrometry from Gaia Data Release 3 and recent 3D extinction maps, to develop a probabilistic scheme in order to select with high confidence RC-like stars.

Our curated catalogue contains about 10 million sources, for which we estimate photometric distances based on the WISE W1 photometry. We then derive the selection function for our sample, which is the combined selection function of sources with both Gaia and AllWISE photometry. Using the distances and accounting for the full selection function of our observables, we are able to fit a two-disc, multi-parameter model to constrain the scale height (hz), scale-length (rd), flaring, and the relative mass ratios of the two disc components.