Unlocking new Studies of Dwarf Galaxies via Fusing Rubin Observatory Optical and VISTA Near Infrared Data

Realising the full potential of LSST’s comprehensive observational initiatives relies on adeptly accessing the rich reservoir of multiwavelength data nestled within the survey fields of Rubin Observatory. Near-infrared filters, as the ideal complement to LSST’s optical bands, harbour vast promise in revealing insights into ageing stellar populations in the outskirts of galaxies.The largest near-infrared survey telescope, VISTA, extensively covers the southern hemisphere with various depth surveys, including VHS, VIKING, SHARKS, VIDEO, VEILS, KEDFS, and more. VISTA data effectively bridges the gap between IR datasets like Euclid (YJH bands) and Spitzer/WISE (> 3.6μm), providing essential K-band coverage for comprehensive studies. Galaxy detections in the K-band offer valuable glimpses into the early Universe, unveiling faint galaxies at z > 2 with evolved stellar populations or significant dust extinction.We have engineered a workflow leveraging LSST science pipelines to seamlessly merge VISTA images with LSST-Cam imaging, enabling joint photometry. This integration promises unprecedented insights into cosmic evolution and galaxy formation. In preparation for the LSST survey, we combined data from Hyper SuprimeCam and VISTA, producing pixel-matched images and multi-band catalogues. Moreover, we conducted initial science verification tests as well as testing data distribution systems through the Rubin UK Data Access Centre.In this presentation, we delve into prototype datasets, examining photometric redshift computation and spectral energy distribution model fitting. Additionally, we outline plans for early science utilizing combined Rubin and VISTA data, showcasing examples with a specific emphasis on identifying dwarf galaxies through our forced photometry catalogue.