UK-led collaboration contributes to largest infrared map of Milky Way

This collage highlights a small selection of regions of the Milky Way imaged as part of the most detailed infrared map ever of our galaxy. Here we see, from left to right and top to bottom: NGC 3576, NGC 6357, Messier 17, NGC 6188, Messier 22 and NGC 3603. All of them are clouds of gas and dust where stars are forming, except Messier 22, which is a very dense group of old stars. The images were captured with ESO's Visible and Infrared Survey Telescope for Astronomy (VISTA) and its infrared camera VIRCAM. The gigantic map to which these images belong contains 1.5 billion objects. The data were gathered over the course of 13 years as part of the VISTA Variables in the Vía Láctea (VVV) survey and its companion project, the VVV eXtended survey (VVVX). Credit: ESO/VVVX survey

This remarkable achievement, carried out by the VISTA Variables in the Vía Láctea (VVV) survey and its extension, the VVV eXtended survey (VVVX), has provided unprecedented insights into the structure and composition of our galaxy. The surveys, conducted over 13 years at the European Southern Observatory’s (ESO) VISTA telescope in Chile, have produced invaluable data for the astronomical community.

Queen Mary University of London played a pivotal role in this project. Professor Jim Emerson from the School of Physical and Chemical Sciences was responsible for overseeing the construction of the VISTA telescope, which began with a £25 million grant from the PPARC’s Joint Infrastructure Fund. "The VISTA telescope was designed with surveys like VVV in mind, enabling astronomers to study objects hidden by interstellar dust," said Professor Emerson. Queen Mary's Dr Will Sutherland served as the Project Scientist for the design, construction and testing of VISTA.

The VVV and VVVX surveys, initiated in 2010, required 420 nights of observation, capturing around 200,000 images and generating approximately 500 terabytes of scientific data. The data has already led to more than 300 scientific publications and 30 doctoral theses, with countless discoveries expected in the coming years.

Key collaborators included Professor Dante Minniti from Universidad Andrés Bello (UNAB) in Chile and Professor Philip Lucas from the University of Hertfordshire. The team also comprised 146 co-authors from 15 countries, spanning four continents.

Notable discoveries from the surveys include globular clusters, hypervelocity stars, and unknown variable objects referred to as "WIT" (What Is This?). The surveys have also uncovered new insights into brown dwarfs, binary floating planets, and the oldest RR Lyrae stars at the Galaxy's center.

The VISTA telescope, which boasts the world’s largest infrared camera, VIRCAM, was developed by the UK Astronomy Technology Centre (UK ATC) in collaboration with the University of Durham. The telescope's ability to peer through dust and gas has opened new avenues for understanding stellar populations and galactic structure.

Professor Emerson reflected on the international collaboration's significance: "The VVV survey is a testament to the global effort in astronomy, and VISTA’s contributions will continue to shape our understanding of the universe for decades."

Collaborators:

• Queen Mary University of London
• Universidade Federal de Santa Catarina (UFSC), Brazil
• Universidad Andrés Bello (UNAB), Chile
• University of Hertfordshire
• UK Astronomy Technology Centre (UK ATC)
• 18 UK universities in the VISTA Consortium

The VVV and VVVX surveys have left a lasting legacy, and future projects, including NASA’s Nancy Roman Space Telescope, will build on this vast trove of data.