VizieR Online Data Catalog: MLSDSS-GaiaDR2 sample of M and L dwarfs (Kiman+, 2019)

In this paper, we present the MLSDSS-GaiaDR2 sample of M and L dwarfs including spectral types, Hα measurements, survey photometry, and Galactic kinematics. The compilation of the MLSDSS-GaiaDR2 sample was accomplished in two parts: assembling the base sample, dubbed the "MLSDSS" sample, and then cross-matching it with the Gaia Data Release 2 (DR2; Gaia Collaboration et al. 2018, Cat. I/345). The MLSDSS sample is based on data from the SDSS Data Releases 7, 10, and 12 (DR7; DR10; DR12; Abazajian et al. 2009, Cat. II/294; Ahn et al. 2014ApJS..211....1H; Alam et al. 2015, Cat. V/147) and the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS; Eisenstein et al. 2011AJ....142...72E; Dawson et al. 2013AJ....145...10D). We cross-matched the MLSDSS sample with Gaia DR2 to obtain precise proper motions and parallaxes. First, we propagated the positions from the SDSS epoch (ranging from 1999 to 2007) to the Gaia DR2 epoch (2015.5) using the proper motions in MLSDSS. Second, we queried the Gaia Archive (http://gea.esac.esa.int/archive/) and selected all the objects within a radius of 5" of the 2015.5 position. We found that 98% (73003 stars) of MLSDSS stars have at least one match in Gaia DR2. Of these, 8269 have between two and five matches within a 5" radius. To find a single best match, we propagated the position of each match back to the SDSS epoch using the Gaia DR2 proper motion and kept only the closest match between the Gaia position at the SDSS epoch and the SDSS position.

(1 data file).