The VISTA Variables in the Vía Láctea extended (VVVX) ESO public survey: Completion of the observations and legacy^★

¹ Departamento de Física, Universidade Federal de Santa Catarina, Trindade, 88040-900, Florianópolis, Brazil
e-mail: roberto.saito@ufsc.br
² Instituto de Astrofísica, Dep. de Ciencias Físicas, Facultad de Ciencias Exactas, Universidad Andres Bello, Av. Fernández Concha 700, Santiago, Chile
³ Max-Planck Institute for Astronomy, Königstuhl 17, 69117 Heidelberg, Germany
⁴ Centro de Astronomía (CITEVA), Universidad de Antofagasta, Av. Angamos 601, Antofagasta, Chile
⁵ Millennium Institute of Astrophysics (MAS), Nuncio Monseñor Sotero Sanz 100, Of. 104, Providencia, Santiago, Chile
⁶ Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield AL1 09A, UK
⁷ Vatican Observatory, Specola Vaticana, 00120 Vatican City, Vatican City State
⁸ Departamento de Geofísica y Astronomía, CONICET, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de San Juan, Av. Ignacio de la Roza 590 (O), J5402DCS, Rivadavia, San Juan, Argentina
⁹ Instituto de Astronomía Teórica y Experimental (IATE-CONICET), Laprida 854, X5000BGR, Córdoba, Argentina
¹⁰ Observatorio Astronómico de Córdoba, Universidad Nacional de Córdoba, Laprida 854, X5000BGR, Córdoba, Argentina
¹¹ Instituto de Física y Astronomía, Universidad de Valparaíso, ave. Gran Bretaña, 1111, Casilla 5030, Valparaíso, Chile
¹² Millennium Institute of Astrophysics, Nuncio Monseñor Sotero Sanz 100, Of. 104, Providencia, Santiago, Chile
¹³ Gemini Observatory, Northern Operations Center, 670 A’ohoku Place, Hilo, HI 96720, USA
¹⁴ Wide-Field Astronomy Unit, Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK
¹⁵ European Southern Observatory, Alonso de Córdova 3107, Casilla 19001, Vitacura, Santiago, Chile
¹⁶ European Southern Observatory, Karl Schwarzschildstr 2, 85748 Garching bei München, Germany
¹⁷ INAF – Osservatorio Astronomico di Capodimonte, Salita Moiariello 16, 80131 Napoli, Italy
¹⁸ Mount Saint Vincent University, Halifax B3M 2J6, Canada
¹⁹ INAF – Osservatorio Astronomico di Roma, Via di Frascati 33, 00078 Monte Porzio Catone, Roma, Italy
²⁰ Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
²¹ Institute of Astronomy, University of Cambridge, Madingley Rd., Cambridge CB3 0HA, UK
²² Departamento de Física, Universidade Estadual de Feira de Santana (UEFS), Av. Transnordestina, S/N, CEP 44036-900 Feira de Santana, BA, Brazil
²³ Gemini Observatory/NSF’s NOIRLab, Casilla 603, La Serena, Chile
²⁴ Departamento de Astronomía, Universidad de La Serena, Av. Juan Cisternas 1200 Norte, La Serena, Chile
²⁵ Universidade de São Paulo, IAG, Rua do Matão 1226, Cidade Universitária, São Paulo 05508-090, Brazil
²⁶ Fundación Chilena de Astronomía, El Vergel 2252, Santiago, Chile
²⁷ Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, Padova 35122, Italy
²⁸ Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
²⁹ Department of Physics, University of Wisconsin-Whitewater, 800 West Main Street, Whitewater, WI 53190, USA
³⁰ Departamento de Astronomia, Instituto de Física, UFRGS, Av. Bento Gonçalves 9500, Porto Alegre, RS, Brazil
³¹ Instituto de Ciências Naturais, Humanas e Sociais, Universidade Federal de Mato Grosso, Cidade Jardim, 78550-728 Sinop, Brazil
³² Vatican Observatory, VORG, Steward Observatory, 933 N. Cherry Avenue, Tucson, AZ, USA
³³ Gerencia De Vinculación Tecnológica, Comisión Nacional de Actividades Espaciales (GVT-CONAE), Falda del Cañete, Córdoba, Argentina
³⁴ Colégio Militar de Porto Alegre, Ministério da Defesa, Exército Brasileiro, Av. José Bonifácio 363, Porto Alegre 90040-130, RS, Brazil
³⁵ Instituto de Alta Investigación, Universidad de Tarapacá, Casilla 7D, Arica, Chile
³⁶ Instituto de Astrofísica,Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 7820436 Macul, Santiago, Chile
³⁷ Centro de Astro-Ingeniería, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 7820436 Macul, Santiago, Chile
³⁸ Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2290, Ciudad Autónoma de Buenos Aires C1425FQB, Argentina
³⁹ Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea, 2 Research Institute of Basic Sciences, Seoul National University, Seoul 08826, Republic of Korea
⁴⁰ Departamento de Tecnologías Industriales, Faculty of Engineering, Universidad de Talca, Merced 437, Curicó, Chile
⁴¹ Departamento de Física de la Tierra y Astrofísica & IPARCOSUCM (Instituto de Física de Partículas y del Cosmos de la UCM), Facultad de Ciencias Físicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
⁴² Centro de Astrobiología (CAB), CSIC-INTA, Camino Bajo del Castillo s/n, 28692, Villanueva de la Cañada, Madrid, Spain
⁴³ Facultad de Matemática, Astronomía, Física y Computación, Universidad Nacional de Córdoba (UNC), Córdoba, Argentina
⁴⁴ University of Central Lancashire, Preston, PR1 2HE, UK
⁴⁵ Instituto de Ciencias Astronómicas, de la Tierra y del Espacio (ICATE, CONICET), C.C. 467, 5400, San Juan, Argentina
⁴⁶ Astronomy Unit, School of Physical and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
⁴⁷ Instituto de Astronomía, Universidad Católica del Norte, Av. Angamos 0610, Antofagasta, Chile
⁴⁸ Department of Astronomy, Yale University, 219 Prospect Street, New Haven, CT 06511, USA
⁴⁹ Instituto de Astronomía y Ciencias Planetarias, Universidad de Atacama, Copayapu 485, Copiapó, Chile
⁵⁰ Laboratorio Nacional de Astrofísica LNA/MCTI, 37504-364 Itajubá, MG, Brazil
⁵¹ Centre for Astrophysics and Planetary Science, School of Physics and Astronomy, University of Kent, Canterbury CT2 7NH, UK
⁵² Departamento de Astronomia, Casilla 160-C, Universidad de Concepcion, Chile
⁵³ Instituto Multidisciplinario de Investigación y Postgrado, Universidad de La Serena, Raúl Bitrán 1305, La Serena, Chile
⁵⁴ Max-Planck-Institut für Ex. Physik, Giessenbachstrasse, 85748, Garching, Germany
⁵⁵ UK Astronomy Technology Centre, Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ, UK
⁵⁶ Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, Blvd de l’Observatoire, 06304, Nice, France
⁵⁷ Centro Internacional Franco Argentino de Ciencias de la Información y de Sistemas (CIFASIS, CONICET–UNR), Rosario, Argentina
⁵⁸ Dipartimento di Fisica, Università di Ferrara, Via Giuseppe Saragat 1, Ferrara 44122, Italy
⁵⁹ Western Sydney University, Kingswood campus, NSW, Australia
⁶⁰ Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, s/n, 4150-762, Porto, Portugal
⁶¹ Miranda House, University of Delhi, India
⁶² Inter University centre for Astronomy and Astrophysics, Pune, India
⁶³ Universidade Federal do Pampa Br 472, Km 585, CP 118 Uruguaiana, RS, Brazil
⁶⁴ Department of Physics & Astronomy, Texas Tech University, Box 41051, Lubbock TX 79409-1051, USA
⁶⁵ Instituto de Astrofísica de Canarias, Spain
⁶⁶ Departamento de Astrofísica, Universidad de La Laguna, Spain
⁶⁷ Istituto Nazionale di Astrofisica, Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Gobetti 101, I40129, Bologna, Italy
⁶⁸ Department of Astronomy, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
⁶⁹ Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
⁷⁰ Departamento de Astronomía, Universidad de Chile, Camino El Observatorio 1515, Las Condes, Chile
⁷¹ Association of Universities for Research in Astronomy (AURA), Av. Juan Cisternas 1500, La Serena, Chile
⁷² Grupo de Astrofísica Extragaláctica-IANIGLA, CONICET, Universidad Nacional de Cuyo (UNCuyo), Gobierno de Mendoza, Argentina
⁷³ Department of Physics and Astronomy, Johns Hopkins University, Baltimore MD 21218, USA
⁷⁴ Clínica Universidad de los Andes - Dirección Comercial, Av. Plaza 2501, Santiago, Chile
⁷⁵ SOAR Telescope/NSF’s NOIRLab, Avda Juan Cisternas 1500, 1700000 La Serena, Chile
⁷⁶ Centro de Docencia Superior en Ciencias Básicas, Universidad Austral de Chile, Los Pinos s/n, Puerto Montt, Chile
⁷⁷ Centre for Basic Space Science, University of Nigeria, 410101 Nsukka, Nigeria
⁷⁸ Departamento de Matemática, Universidad de Atacama, Copayapu 485, Copiapó, Chile
⁷⁹ NSF NOIRLab/Vera C. Rubin Observatory, Casilla 603, La Serena, Chile
⁸⁰ Instituto de Astronomía y Física del Espacio (IAFE, CONICET-UBA), C1428ZAA, Ciudad Autónoma de Buenos Aires, Argentina
⁸¹ Instituto de Estudios Astrofísicos, Facultad de Ingeniería y Ciencias, Universidad Diego Portales, Av. Ejército Libertador 441, Santiago, Chile
⁸² Max-Planck-Institut für extraterrestrische Physik, Gießenbachstraße 1, 85748 Garching, Germany
⁸³ Thüringer Landessternwarte, Sternwarte 5, 07778 Tautenburg, Germany
⁸⁴ Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK
⁸⁵ Astrobiology Center, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
⁸⁶ National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
⁸⁷ Departamento de Física, FACI, Universidad de Tarapacá, Casilla 7D, Arica, Chile
⁸⁸ Museo Interactivo de la Astronomía, Centro Interactivo de la Conocimientos, Avenida Punta Arenas 6711, La Granja, Chile
⁸⁹ North Optics, Cristóbal Colón # 352 oficina 514, La Serena, Chile
⁹⁰ School of Mathematical and Physical Sciences, Macquarie University, Sydney, NSW 2109, Australia

Received: 2 May 2024
Accepted: 14 June 2024

Abstract

Context. The ESO public survey VISTA Variables in the Vía Láctea (VVV) surveyed the inner Galactic bulge and the adjacent southern Galactic disk from 2009–2015. Upon its conclusion, the complementary VVV extended (VVVX) survey has expanded both the temporal as well as spatial coverage of the original VVV area, widening it from 562 to 1700 sq. deg., as well as providing additional epochs in JHK_s filters from 2016–2023.

Aims. With the completion of VVVX observations during the first semester of 2023, we present here the observing strategy, a description of data quality and access, and the legacy of VVVX.

Methods. VVVX took ~2000 h, covering about 4% of the sky in the bulge and southern disk. VVVX covered most of the gaps left between the VVV and the VISTA Hemisphere Survey (VHS) areas and extended the VVV time baseline in the obscured regions affected by high extinction and hence hidden from optical observations.

Results. VVVX provides a deep JHK_s catalogue of ≳1.5 × 10⁹ point sources, as well as a K_s band catalogue of ~10⁷ variable sources. Within the existing VVV area, we produced a 5D map of the surveyed region by combining positions, distances, and proper motions of well-understood distance indicators such as red clump stars, RR Lyrae, and Cepheid variables.

Conclusions. In March 2023 we successfully finished the VVVX survey observations that started in 2016, an accomplishment for ESO Paranal Observatory upon 4200 h of observations for VVV+VVVX. The VVV+VVVX catalogues complement those from the Gaia mission at low Galactic latitudes and provide spectroscopic targets for the forthcoming ESO high-multiplex spectrographs MOONS and 4MOST.