The future of the VVV survey
The VVV public near-IR variability survey is scanning the Milky Way bulge and an adjacent section of the mid-plane where star formation activity is high. The survey takes ~2000 hours of observations with the 4-metre VISTA telescope, covering a billion point sources across an area of 540 sqdeg, including dozens of known globular clusters and hundreds of open clusters. The final product is a deep IR atlas in five passbands (0.9 − 2.5 microns) and a catalogue of more than a million variable point sources. Unlike single-epoch surveys that, in most cases, only produce 2-D maps, VVV variable star survey enables the construction of 3-D map of the surveyed region using well-understood distance indicators such as RR Lyrae stars, red clump giants, and Cepheids. This survey yields important information on the ages, reddenings and metallicities of the Galactic stellar populations, and also discovers moving objects in the Solar System and beyond. The observations are combined with data from 2MASS, MACHO, OGLE, EROS, VST, Spitzer, HST, Chandra, INTEGRAL, WISE, Fermi LAT, XMM-Newton and ALMA for a complete understanding of the variable sources in the inner Milky Way, and also background sources such as SNe in distant galaxies, AGNs and QSOs. This public survey provides data available to the whole community and therefore enables further studies of the history of the Milky Way, its star cluster evolution, and the population census of the Galactic Bulge and center, as well as the investigations of the star forming regions in the disk. The combined variable star catalogues have important implications for theoretical investigations of pulsation properties of stars and explosive phenomena. In this talk I will present our plans for the extension of the survey: the VVVX proposal.