Galaxies behind the galactic plane: First results and perspectives from the VVV survey

Abstract

VISTA Variables in the Via Láctea (VVV) is an ESO variability survey that is performing observations in near-infrared bands (ZY JHK s) toward the Galactic bulge and part of the disk with the completeness limits at least 3mag deeper than Two Micron All Sky Survey. In the present work, we searched in the VVV survey data for background galaxies near the Galactic plane using ZY JHK s photometry that covers 1.636deg2. We identified 204 new galaxy candidates by analyzing colors, sizes, and visual inspection of multi-band (ZY JHK s) images. The galaxy candidate colors were also compared with the predicted ones by star count models considering a more realistic extinction model at the same completeness limits observed by VVV. A comparison of the galaxy candidates with the expected one by Millennium simulations is also presented. Our results increase the number density of known galaxies behind the Milky Way by more than one order of magnitude. A catalog with galaxy properties including ellipticity, Petrosian radii, and ZY JHK s magnitudes is provided, as well as comparisons of the results with other surveys of galaxies toward the Galactic plane.