The VMC survey

I. Strategy and first data

¹ University of Hertfordshire, Physics Astronomy and Mathematics, Hatfield AL10 9AB, UK
e-mail: m.cioni@herts.ac.uk
² University Observatory Munich, Scheinerstrasse 1, 81679 München, Germany
³ INAF, Osservatorio Astronomico di Bologna, via Ranzani 1, 40127 Bologna, Italy
⁴ INAF, Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, 35122 Padova, Italy
⁵ Royal Observatory of Belgium, Ringlaan 3, 1180 Ukkel, Belgium
⁶ University of Bologna, Department of Astronomy, via Ranzani 1, 40127 Bologna, Italy
⁷ INAF, Osservatorio Astronomico di Capodimonte, via Moiariello 16, 80131 Napoli, Italy
⁸ ICRAR, M468, University of Western Australia, 35 Stirling Hwy, Crawley 6009, Western Australia
⁹ University of Edinburgh, Institute for Astronomy, Blackford Hill, Edinburgh EH9 3HJ, UK
¹⁰ University of Cape Town, Private Bag X3, Rondebosch 7701, South Africa
¹¹ Peking University, Kavli Institute for Astronomy and Astrophysics, Yi He Yuan Lu 5, Hai Dian District, Beijing 100871, PR China
¹² Queen Mary University of London, Mile End Road, London E1 4NS, UK
¹³ UK Astronomy Technology Centre, Blackford Hill, Edinburgh EH9 3HJ, UK
¹⁴ Centre for Astrophysics, University of Central Lancshire, Preston PR1 2HE, UK
¹⁵ University of Cambridge, Institute of Astronomy, Madingley Rd, Cambridge CB3 0HA, UK
¹⁶ European Southern Observatory, Av. Alonso de Córdoba 3107, Casilla 19, Santiago, Chile
¹⁷ UPMC Univ. Paris 06, UMR7095, Institut d’Astrophysique de Paris, 75014 Paris, France
¹⁸ CNRS, UMR7095, Institut d’Astrophysique de Paris, 75014 Paris, France
¹⁹ LERMA, Observatoire de Paris, UPMC, CNRS, 61 Av. de l’Observatoire, 75014 Paris, France
²⁰ University of Zurich, Institute for Theoretical Physics, 8057 Zurich, Switzerland
²¹ University of Exeter, School of Physics, Stocker Road, Exeter EX4 4QL, UK
²² University of Keele, School of Physical and Geographical Sciences, Staffordshire ST5 5BG, UK
²³ University of Leicester, University Road, Leicester LE1 7RH, UK
²⁴ Mount Stromlo Observatory, RSAA, Cotter Road, Weston Creek, ACT 2611, Australia

Received: 12 November 2010
Accepted: 16 December 2010

Abstract

Context. The new VISual and Infrared Telescope for Astronomy (VISTA) has started operations. Over its first five years it will be collecting data for six public surveys, one of which is the near-infrared YJK_s VISTA survey of the Magellanic Clouds system (VMC). This survey comprises the Large Magellanic Cloud (LMC), the Small Magellanic Cloud, the Magellanic Bridge connecting the two galaxies and two fields in the Magellanic Stream.

Aims. This paper provides an overview of the VMC survey strategy and presents first science results. The main goals of the VMC survey are the determination of the spatially-resolved star-formation history and the three-dimensional structure of the Magellanic system. The VMC survey is therefore designed to reach stars as faint as the oldest main sequence turn-off point and to constrain the mean magnitude of pulsating variables such as RR Lyrae stars and Cepheids. This paper focuses on observations of VMC fields in the LMC obtained between November 2009 and March 2010. These observations correspond to a completeness of 7% of the planned LMC fields.

Methods. The VMC data are comprised of multi-epoch observations which are executed following specific time constraints. The data were reduced using the VISTA Data Flow System pipeline with source catalogues, including astrometric and photometric corrections, produced and made available via the VISTA Science Archive. The VMC data will be released to the astronomical community following the European Southern Observatory’s Public Survey policy. The analysis of the data shows that the sensitivity in each wave band agrees with expectations. Uncertainties and completeness of the data are also derived.

Results. The first science results, aimed at assessing the scientific quality of the VMC data, include an overview of the distribution of stars in colour–magnitude and colour–colour diagrams, the detection of planetary nebulae and stellar clusters, and the K_s band light-curves of variable stars.

Conclusions. The VMC survey represents a tremendous improvement, in spatial resolution and sensitivity, on previous panoramic observations of the Magellanic system in the near-infrared, providing a powerful complement to deep observations at other wavelengths.