VISIONS: the VISTA Star Formation Atlas

I. Survey overview^★

¹ Universität Wien, Institut für Astrophysik, Türkenschanzstrasse 17, 1180 Wien, Austria
e-mail: stefan.meingast@univie.ac.at
² Université de Bordeaux, Lab. d’Astrophysique de Bordeaux, CNRS, B18N, Allée Geoffroy Saint-Hillaire, 33615 Pessac, France
³ European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching bei München, Germany
⁴ Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
⁵ Universidade do Porto, Faculdade de Engenharia, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
⁶ Universidade de Lisboa, Faculdade de Ciências, CENTRA, Ed. C8, Campo Grande, 1749-016 Lisboa, Portugal
⁷ Universidad de Valparaiso, Instituto de Física y Astronomía, Gran Bretaña 1111, Valparaiso, Chile
⁸ Leiden University, Leiden Observatory, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands
⁹ University of Hertfordshire, Centre for Astrophysics Research, College Lane, Hatfield AL10 9AB, UK
¹⁰ Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA
¹¹ The CHARA Array of Georgia State University, Mount Wilson Observatory, Mount Wilson, CA 91023, USA
¹² Università degli Studi di Milano, Dipartimento di Fisica via Celoria 16, 20133 Milano, Italy
¹³ Universidad de Chile, Departamento de Astronomía, Las Condes, Santiago, Chile
¹⁴ Terma GmbH, Bratustraße 7, 64293 Darmstadt, Germany
¹⁵ European Space Agency (ESA), European Space Research and Technology Centre (ESTEC), Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands
¹⁶ Universidad de Antofagasta, Centro de Astronomía (CITEVA), Av. Angamos 601, Antofagasta, Chile
¹⁷ Johannes Kepler University Linz, Industrial Mathematics Institute, Altenbergerstraße 69, 4040 Linz, Austria
¹⁸ Johann Radon Institute for Computational and Applied Mathematics (RICAM), Austrian Academy of Sciences (AAS), Altenbergerstr. 69, 4040 Linz, Austria
¹⁹ University of Vienna, Research Network Data Science at Uni Vienna, Austria
²⁰ INAF – Osservatorio Astrofisico di Arcetri, Largo E. Fermi, 5, 50125 Firenze, Italy
²¹ University of St Andrews, SUPA, School of Physics & Astronomy, North Haugh, St Andrews KY16 9SS, UK
²² Space Telescope Science Institute, 3700 San Martin Dr, Baltimore, MD 21218, USA

Received: 22 December 2022
Accepted: 19 January 2023

Abstract

VISIONS is an ESO public survey of five nearby (d < 500 pc) star-forming molecular cloud complexes that are canonically associated with the constellations of Chamaeleon, Corona Australis, Lupus, Ophiuchus, and Orion. The survey was carried out with the Visible and Infrared Survey Telescope for Astronomy (VISTA), using the VISTA Infrared Camera (VIRCAM), and collected data in the near-infrared passbands J (1.25 μm), H (1.65 μm), and K_S (2.15 μm). With a total on-sky exposure time of 49.4h VISIONS covers an area of 650 deg², it is designed to build an infrared legacy archive with a structure and content similar to the Two Micron All Sky Survey (2MASS) for the screened star-forming regions. Taking place between April 2017 and March 2022, the observations yielded approximately 1.15 million images, which comprise 19 TB of raw data. The observations undertaken within the survey are grouped into three different subsurveys. First, the wide subsurvey comprises shallow, large-scale observations and it has revisited the star-forming complexes six times over the course of its execution. Second, the deep subsurvey of dedicated high-sensitivity observations has collected data on areas with the largest amounts of dust extinction. Third, the control subsurvey includes observations of areas of low-to-negligible dust extinction. Using this strategy, the VISIONS observation program offers multi-epoch position measurements, with the ability to access deeply embedded objects, and it provides a baseline for statistical comparisons and sample completeness – all at the same time. In particular, VISIONS is designed to measure the proper motions of point sources, with a precision of 1 mas yr⁻¹ or better, when complemented with data from the VISTA Hemisphere Survey (VHS). In this way, VISIONS can provide proper motions of complete ensembles of embedded and low-mass objects, including sources inaccessible to the optical ESA Gaia mission. VISIONS will enable the community to address a variety of research topics from a more informed perspective, including the 3D distribution and motion of embedded stars and the nearby interstellar medium, the identification and characterization of young stellar objects, the formation and evolution of embedded stellar clusters and their initial mass function, as well as the characteristics of interstellar dust and the reddening law.