Herts professor leads survey of largest ever infrared map of the Galaxy
A University of Hertfordshire Professor of Astrophysics has played a leading role in mapping our Galaxy, the Milky Way.
Professor Philip Lucas, from Herts Centre for Astrophysics Research (CAR) co-led an international survey team that has mapped over 1.5 billion objects in the Milky Way using infrared technology.
The research has just been published in the journal, Astronomy & Astrophysics.
Mapping the Milky Way has taken some 13 years and involved an international range of research partners. These include the VISTA (Visible and Infrared Survey Telescope for Astronomy), a European Southern Observatory (ESO) facility in Chile.
The VISTA Variables in the Vía Láctea (VVV) survey and its extension, the VVV eXtended survey (VVVX), observed the central regions of the Milky Way.
It was these VVV and VVVX surveys that were led by Professor Lucas and Professor Dante Minniti from UNAB and principal investigator at the Center for Astrophysics and Related Technologies.
Beginning in 2010, these surveys required 420 nights of observation to capture around 200,000 images, monitoring over 1.5 billion celestial objects and generating 500 terabytes of scientific data. This represents the largest volume of data ever collected for an ESO observational project.
Professor Lucas said: "By mapping the Milky Way in the infrared, we were able to pierce the obscuring veil of interstellar dust and gas that hides most of our Galaxy in visible light."
Numerous discoveries have been made possible by the surveys’ extensive dataset which has already produced more than 300 scientific publications and 30 doctoral theses in South America and Europe, covering an incredible range of topics such as galactic structure, stellar populations, variable stars, star clusters and much more.
Notable discoveries include:
- Globular clusters: The oldest objects in our Galaxy.
- Hypervelocity stars: Stars expelled from the Galaxy by the central supermassive black hole.
- Galactic windows: Clear views through interstellar dust and gas to the other side of the Galaxy.
- RR Lyrae variable stars: The oldest known population in the centre of the Galaxy.
- Brown dwarf stars and binary floating planets: Unique celestial objects that enhance our understanding of stellar and planetary formation.
Dante Minniti, an astrophysicist at Universidad Andrés Bello in Chile, said: “We made so many discoveries, we have changed the view of our Galaxy forever.”
UK role on VISTA
Working closely with partners across 18 UK Universities in the VISTA Consortium, the Science and Technology Facilities Council, through its team at the UK Astronomy Technology Centre (UK ATC) in Edinburgh, played a key role in the development and delivery of the telescope to ESO. In addition, the Imaging Systems group from STFC’s RAL Space (alongside collaborators from UK ATC and the University of Durham) were responsible for the design and construction of the Infrared camera, which at the time it was built was the largest ever produced.
With a 4.1m mirror VISTA is the world's largest dedicated infrared survey telescope.
VISTA’s infrared camera VIRCAM, can peer through the dust and gas that permeates our galaxy. By observing at wavelengths longer than those visible to the human eye, VISTA has the capability to study objects that would otherwise remain nearly invisible in visible light. Such as brown dwarfs (‘failed’ stars that do not have sustained nuclear fusion) or free-floating planets that don’t orbit a star.
Delivery of VISTA was also a major part of the UK becoming a member of ESO.
Amazing discoveries
Dr Oscar Gonzalez, Senior Project Scientist at UK ATC and co-author of the Astronomy & Astrophysics paper detailing the research, said: “The completion of the largest infrared map of the Milky Way is a remarkable achievement for the astronomy community. The data has provided unprecedented insights into the structure and composition of the Milky Way and will continue to open new avenues for future research that will enhance our understanding of the Universe for years to come.”
The University of Hertfordshire has around 50 research astrophysicists on its staff, with some 30 postgraduate students also researching astrophysics. It has one of the country’s best-equipped teaching observatories, at Bayfordbury.