Milky Way demographics with the VVV survey
IV. PSF photometry from almost one billion stars in the Galactic bulge and adjacent southern disk⋆
1 Centro de Astronomía (CITEVA), Universidad de Antofagasta, Av. Angamos 601, Antofagasta, Chile
2 Instituto Milenio de Astrofísica, Santiago, Chile
3 Departamento de Física, Universidade Federal de Santa Catarina, Trindade, 88040-900 Florianópolis, SC, Brazil
4 Instituto de Astrofísica, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 782-0436 Macul, Santiago, Chile
5 Departamento de Física, Facultad de Ciencias Exactas, Universidad Andrés Bello, Av. Fernández Concha 700, Las Condes, Santiago, Chile
6 Vatican Observatory, 00120 Vatican City State, Italy
7 SUPA (Scottish Universities Physics Alliance) Wide-Field Astronomy Unit, Institute for Astronomy, School of Physics and Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK
8 UK Astronomy Technology Centre, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK
9 Centre for Astrophysics, University of Hertfordshire, Hatfield AL10 9AB, UK
10 Observatorio Astronómico, Universidad Nacional de Córdoba, Laprida 854, X5000BGR Córdoba, Argentina
11 European Southern Observatory, Karl-Schwarszchild-Str. 2, 85748 Garching bei Muenchen, Germany
Accepted: 23 July 2018
Context. The inner regions of the Galaxy are severely affected by extinction, which limits our capability to study the stellar populations present there. The Vista Variables in the Vía Láctea (VVV) ESO Public Survey has observed this zone at near-infrared wavelengths where reddening is highly diminished.
Aims. By exploiting the high resolution and wide field-of-view of the VVV images we aim to produce a deep, homogeneous, and highly complete database of sources that cover the innermost regions of our Galaxy.
Methods. To better deal with the high crowding in the surveyed areas, we have used point spread function (PSF)-fitting techniques to obtain a new photometry of the VVV images, in the ZY JHKs near-infrared filters available.
Results. Our final catalogs contain close to one billion sources, with precise photometry in up to five near-infrared filters, and they are already being used to provide an unprecedented view of the inner Galactic stellar populations. We make these catalogs publicly available to the community. Our catalogs allow us to build the VVV giga-CMD, a series of color-magnitude diagrams of the inner regions of the Milky Way presented as supplementary videos. We provide a qualitative analysis of some representative CMDs of the inner regions of the Galaxy, and briefly mention some of the studies we have developed with this new dataset so far.
Key words: techniques: photometric / catalogs / surveys / Galaxy: bulge / Galaxy: disk / Galaxy: stellar content
Movies associated to Figs. 6 and 7 are available at https://www.aanda.org
© ESO 2018