VISTA gigapixel mosaic of the central parts of the Milky Way
(Credit: ESO/VVV Consortium
Acknowledgement: Ignacio Toledo, Martin Kornmesser))
A nine-gigapixel zoomable image of 84 million stars has been created by an international team of astronomers using the UK-built VISTA infrared survey telescope at ESO’s Paranal Observatory. The image is so large that, if printed with the resolution of the average book, it would be nine metres long and seven metres tall. The huge dataset contains ten times more stars than previous studies and is a major step forward for the understanding of our home galaxy, the Milky Way.
"This gigantic image is an impressive testament to the quality of the images being taken at the VISTA telescope which UK astronomers and engineers conceived, designed and built for delivery to its home at the European Southern Observatory site in Chile's Atacama desert", said Jim Emerson from Queen Mary, University of London which leads the VISTA consortium. "The unprecedented detail on numbers, types, and locations of stars towards the centre of our Galaxy is giving us exciting new tools to test competing models for how our galaxy is really structured and came to be as it is”, he added. Queen Mary is one of two UK institutions named on the paper. The other is the University of Hertfordshire.
Most spiral galaxies, including our home galaxy, the Milky Way, have a large concentration of ancient stars surrounding the centre, that astronomers call the bulge. Understanding the formation and evolution of the Milky Way’s bulge is vital for understanding the galaxy as a whole.
“By observing in detail the myriads of stars surrounding the centre of the Milky Way we can learn a lot more about the formation and evolution of not only our galaxy, but also spiral galaxies in general,” explains lead author of the study, Roberto Saito (Pontificia Universidad Católica de Chile, Universidad de Valparaíso and The Milky Way Millennium Nucleus, Chile).
However, as Dante Minniti, co-author of the study explains, obtaining detailed observations of this region is not an easy task: “Observations of the bulge of the Milky Way are very hard because it is obscured by dust. To peer into the heart of the galaxy, we need to observe in infrared light, which is less affected by the dust.”
The large mirror, wide field of view and very sensitive infrared detectors of VISTA make it by far the best tool for this job. VISTA was designed by STFC’s UK Astronomy Technology Centre (UK ATC) who also Project Managed the manufacture and assembly of the facility. Gary Rae, Head of Engineering, UK ATC said: “It’s really great to see VISTA performing impeccably for ESO and achieving world-class science for the community; this is a fitting reward to the engineers and scientists from the UK who were involved in the delivery of this technically challenging project.”
The team of astronomers is using data from one of six public surveys carried out with VISTA, the VISTA Variables in the Via Lactea programme (VVV), The data has been used to create a monumental 108 200 by 81 500 pixel colour image containing nearly nine billion pixels, one of the biggest astronomical images ever produced. The processing of VISTA's raw images into the astronomically useful calibrated images which were then used to construct this image was carried out at the Cambridge Astronomical Survey Unit, a part of the UK's VISTA Data Flow System.
Professor Richard Holdaway, Director, STFC’s RAL Space where the camera was built, said; “Sometimes in astronomy there are moments when you simply think, wow! This is one of those times. The detail unveiled through the scale of the image and the technical excellence by the teams who helped achieve this is incredible. It really will allow us to push the boundaries of what we know about our home galaxy.”
The new colour–magnitude diagram of the bulge contains a treasure trove of information about the structure and content of the Milky Way. One interesting result is the large number of faint red dwarf stars. These are prime candidates around which to search for small exoplanets using the transit method.
This research was presented in a paper “Milky Way Demographics with the VVV Survey I. The 84 Million Star Colour–Magnitude Diagram of the Galactic Bulge“ by R. K. Saito et al., which was published in the journal Astronomy & Astrophysics (A&A, 544, A147).
The team is composed of R. K. Saito (Pontificia Universidad Católica de Chile, Santiago, Chile; Universidad de Valparaíso, Chile; The Milky Way Millennium Nucleus, Chile), D. Minniti (Pontificia Universidad Católica de Chile; Vatican Observatory), B. Dias (Universidade de São Paulo, Brazil), M. Hempel (Pontificia Universidad Católica de Chile), M. Rejkuba (ESO, Garching, Germany), J. Alonso-García (Pontificia Universidad Católica de Chile), B. Barbuy (Universidade de São Paulo), M. Catelan (Pontificia Universidad Católica de Chile), J. P. Emerson (Queen Mary University of London, United Kingdom), O. A. Gonzalez (ESO, Garching, Germany), P. W. Lucas (University of Hertfordshire, Hatfield, United Kingdom) and M. Zoccali (Pontificia Universidad Católica de Chile).
The paper can be found here.
The latest image from VISTA can be found here on ESO’s press release (link opens in a new window).
Further photos of VISTA can be found here (link opens in a new window).
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Queen Mary, University of London is the lead institute of the VISTA consortium. STFC’s UK ATC were responsible for the design and led the construction of the VISTA telescope, working closely with RAL Space to develop the camera. RAL Space was responsible for much of the detailed design of the camera, and performed the overall camera assembly and performance testing.
The VISTA consortium consists of:
• Queen Mary University of London
• Queen’s University of Belfast
• University of Birmingham
• University of Cambridge
• Cardiff University
• University of Central Lancashire
• Durham University
• The University of Edinburgh
• University of Hertfordshire
• Keele University
• Leicester University
• Liverpool John Moores University
• University of Nottingham
• University of Oxford
• University of St Andrews
• University of Southampton
• University of Sussex
• University College London
Queen Mary, University of London is one of the UK's leading research-focused higher education institutions with some 16,900 undergraduate and postgraduate students.
Amongst the largest of the colleges of the University of London, Queen Mary is a member of the Russell Group, which represents the 24 leading universities in the UK.
Queen Mary’s 3,800 staff deliver world class degree programmes and research across 21 academic departments and institutes, within three sectors: Science and Engineering; Humanities, Social Sciences and Laws; and the School of Medicine and Dentistry.
Queen Mary is ranked 11th in the UK according to the Guardian analysis of the 2008 Research Assessment Exercise, and has been described as ‘the biggest star among the research-intensive institutions’ by the Times Higher Education.
The College has a strong international reputation, with around 20 per cent of students coming from over 100 countries. Queen Mary has an annual turnover of £300 million, research income worth £70 million, and generates employment and output worth £600 million to the UK economy each year.
The College is unique amongst London's universities in being able to offer a completely integrated residential campus, with a 2,000-bed award-winning Student Village on its Mile End campus.
The year 2012 marks the 50th anniversary of the founding of the European Southern Observatory (ESO). ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive astronomical observatory. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 40-metre-class European Extremely Large optical/near-infrared Telescope, the E-ELT (link opens in a new window), which will become “the world’s biggest eye on the sky”.
The Science and Technology Facilities Council is keeping the UK at the forefront of international science and tackling some of the most significant challenges facing society such as meeting our future energy needs, monitoring and understanding climate change, and global security.
The Council has a broad science portfolio and works with the academic and industrial communities to share its expertise in materials science, space and ground-based astronomy technologies, laser science, microelectronics, wafer scale manufacturing, particle and nuclear physics, alternative energy production, radio communications and radar.
STFC operates or hosts world class experimental facilities including:
• in the UK; ISIS pulsed neutron source, the Central Laser Facility, and LOFAR. STFC is also the majority shareholder in Diamond Light Source Ltd.
• overseas; telescopes on La Palma and Hawaii
It enables UK researchers to access leading international science facilities by funding membership of international bodies including European Laboratory for Particle Physics (CERN), the Institut Laue Langevin (ILL), European Synchrotron Radiation Facility (ESRF) and the European Southern Observatory (ESO).
STFC is one of seven publicly-funded research councils. It is an independent, non-departmental public body of the Department for Business, Innovation and Skills (BIS).