The VISTA Variables in the Vía Láctea eXtended (VVVX) ESO public survey: Completion of the observations and legacy

Vol. 689
14. Catalogs and data

The VISTA Variables in the Vía Láctea eXtended (VVVX) ESO public survey: Completion of the observations and legacy

The low-latitude regions of the Milky Way are a hostile environment for optical astronomers, owing to the high extinction obscuring the targets of interest. Therefore, it is imperative to resort to large-scale, infrared surveys to unravel the diverse populations and astrophysics that make up the central parts of our Galaxy. With the final release of its vast dataset (several tens of Tb), the VISTA Variables in the Vía Láctea eXtended (VVVX) survey lays a new foundation for studying stellar populations at low latitudes in the infrared JHKs filters. Combining the earlier VVV and its extension (VVVX), 4% of the sky was sampled at a time coverage of 4200 hours over 15 years. This all came to fruition by the release of data for over 1.5 billion point sources, including their proper motions and distances, using well-calibrated distance indicators such as red clump or variable RR Lyrae stars. The resulting unique map allows for a vast range of science returns, from the discovery and characterization of hidden star clusters, to the study of low-mass stars and exoplanets, monitoring of microlensing events, and, last but not least, the eponymous variable stars.