A Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE)

I. Introduction to the survey^★

¹ Aix-Marseille Université, CNRS, CNES, LAM (Laboratoire d’Astrophysique de Marseille), UMR 7326, 13388 Marseille, France
e-mail: alessandro.boselli@lam.fr
² Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse 1, 85748 Garching, Germany
e-mail: mfossati@mpe.mpg.de
³ Universitäts-Sternwarte München, Scheinerstrasse 1, 81679 München, Germany
⁴ NRC Herzberg Astronomy and Astrophysics, 5071 West Saanich Road, Victoria, BC V9E 2E7, Canada
e-mail: laura.ferrarese@nrc-cnrc.gr.ca
⁵ Università di Milano-Bicocca, Piazza della Scienza 3, 20100 Milano, Italy
⁶ INAF – Osservatorio Astronomico di Brera, via Brera 28, 20159 Milano, Italy
⁷ Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871, PR China
⁸ Department of Physics and Astronomy, University of Waterloo, Waterloo, ON N2L 3G1, Canada
⁹ Department of Physics & Astronomy, University of Western Ontario, London, ON N6A 3K7, Canada
¹⁰ Unidad de Astronomía, Facultad de Ciencias Básicas, Universidad de Antofagasta, Avda. U. de Antofagasta 02800, Antofagasta, Chile
¹¹ Institut d’Astrophysique Spatiale, UMR 8617, Université Paris-Sud, Bâtiment 121, 91405 Orsay, France
¹² Laboratoire d’Astrophysique de Bordeaux, Université de Bordeaux, CNRS, B18N, allée Geoffroy Saint-Hilaire, 33615 Pessac, France
¹³ Collège de France, 11 Pl. M. Berthelot, 75005 Paris, France
¹⁴ LERMA, Observatoire de Paris, CNRS, PSL Research University, Sorbonne Universités, UPMC Univ. Paris 06, 75014 Paris, France
¹⁵ IRAP, Institut de Recherche en Astrophysique et Planétologie, CNRS, 14 avenue Edouard Belin, 31400 Toulouse, France
¹⁶ International Centre for Radio Astronomy Research, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
¹⁷ CEA/IRFU/SAP, Laboratoire AIM Paris-Saclay, CNRS/INSU, Université Paris Diderot, Observatoire de Paris, PSL Research University, 91191 Gif-sur-Yvette Cedex, France
¹⁸ Université Laval, 2325, rue de l’université, Québec, QC G1V 0A6, Canada
¹⁹ Institute for Computational Cosmology and Centre for Extragalactic Astronomy, Department of Physics, Durham University, South Road, Durham DH1 3LE, UK
²⁰ Department of Physics & Astronomy, McMaster University, Hamilton ON L8S 4K1, Canada
²¹ Department of Astrophysics, University of Vienna, Türkenschanzstrasse 17, 1180 Vienna, Austria
²² Australia Telescope National Facility, CSIRO Astronomy and Space Science, PO Box 76, Epping, NSW 1710, Australia
²³ Department of Physics and Astronomy, University of Victoria, PO Box 1700 STN CSC, Victoria, BC V8W 2Y2, Canada
²⁴ Department of Physics and Astronomy, Trent University, 1600 West Bank Drive, Peterborough, ON K9L 0G2, Canada
²⁵ Department of Astronomy, Peking University, Beijing 100871, PR China
²⁶ Laboratório de Astrofísica Teórica e Observacional, Universidade Estadual de Santa Cruz, 45650-000 Ilhéus, Brazil
²⁷ Institut d’Astrophysique de Paris, UMR7095 CNRS, Université P. & M. Curie, 98bis Bd. Arago, 75104 Paris, France
²⁸ Astronomy Centre, Department of Physics and Astronomy, University of Sussex, Falmer, Brighton BN1 9QH, UK
²⁹ UK Astronomy Technology Centre, Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ, UK
³⁰ Osservatorio Astronomico di Cagliari, via della Scienza 5, 09047 Selargius, Cagliari, Italy
³¹ Department of Physics, Royal Military College of Canada, PO Box 17000, Station Forces, Kingston, ON K7L 7B4, Canada
³² Department of Physics, Engineering Physics, and Astronomy, Queen’s University, Kingston, ON K7L 3N6, Canada
³³ Department of Physics and Astronomy, University of Alabama in Huntsville, Huntsville, AL 35899, USA
³⁴ Center for Computational Astrophysics, Flatiron Institute, 162 5th Avenue, New York, NY 10003, USA
³⁵ Observatoire Astronomique de Strasbourg, UMR 7750, 11, rue de l’Université, 67000 Strasbourg, France
³⁶ LUPM, Université de Montpellier, CNRS, Pl. Eugène Bataillon, 34095 Montpellier, France
³⁷ Canada France Hawaii Telescope Corporation, Kamuela, HI 96743, USA

Received: 4 December 2017
Accepted: 7 February 2018

Abstract

The Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE) is a blind narrow-band (NB) Hα+[NII] imaging survey carried out with MegaCam at the Canada–France–Hawaii Telescope. The survey covers the whole Virgo cluster region from its core to one virial radius (104 deg²). The sensitivity of the survey is of f(Hα) ~ 4 × 10⁻¹⁷ erg s⁻¹ cm⁻² (5σ detection limit) for point sources and Σ(Hα) ~ 2 × 10⁻¹⁸ erg s⁻¹ cm⁻² arcsec⁻² (1σ detection limit at 3 arcsec resolution) for extended sources, making VESTIGE the deepest and largest blind NB survey of a nearby cluster. This paper presents the survey in all its technical aspects, including the survey design, the observing strategy, the achieved sensitivity in both the NB Hα+[NII] and in the broad-band r filter used for the stellar continuum subtraction, the data reduction, calibration, and products, as well as its status after the first observing semester. We briefly describe the Hα properties of galaxies located in a 4 × 1 deg² strip in the core of the cluster north of M87, where several extended tails of ionised gas are detected. This paper also lists the main scientific motivations for VESTIGE, which include the study of the effects of the environment on galaxy evolution, the fate of the stripped gas in cluster objects, the star formation process in nearby galaxies of different type and stellar mass, the determination of the Hα luminosity function and of the Hα scaling relations down to ~10⁶ M_⊙ stellar mass objects, and the reconstruction of the dynamical structure of the Virgo cluster. This unique set of data will also be used to study the HII luminosity function in hundreds of galaxies, the diffuse Hα+[NII] emission of the Milky Way at high Galactic latitude, and the properties of emission line galaxies at high redshift.