Leveraging Large-Sky Surveys in the Gaia Era to Reveal the Nature of Wide Substellar Companions

The last decade has seen the discovery of a growing population of planetary-mass companions (≲20 M_Jup; PMCs) to young stars which are often still in the star-forming regions where they formed. These objects have been found at wide separations (>100 au) from their host stars, challenging existing models of both star and planet formation. Demographic trends with mass and separation should distinguish between these formation models. While the number of wide-orbit PMCs known has increased slowly, there is tremendous opportunity to search for wide companions in publicly available legacy data sets (e.g., Spitzer/IRAC, Pan-STARRS, UKIDSS, VHS). Furthermore, with the Gaia mission revolutionizing our understanding of the stars in the Milky Way by precisely mapping their positions and movements, an additional opportunity arises to efficiently discover more wide substellar and planetary-mass companions. In this talk I will present my efforts to increase the number of wide-orbit PMCs known through an automated PSF-subtraction pipeline I developed. I will then present how I utilized Gaia to confirm a ρ = 4.66" (540 au), M = 20 M_Jup companion to [SCH06] J0359+2009, a young brown dwarf in Taurus, and describe my ongoing follow-up observations to characterize this system. Finally, I will conclude by reviewing the outlook for future Gaia data releases and how it will further our understanding of binary systems into the planetary-mass regime.