Cambridge Astronomical Survey Unit, 2005-10

Lead Research Organisation: University of Cambridge
Department Name: Institute of Astronomy


Observational astronomy in the UK is in a strong position with the advent of the pioneering near-infrared survey facilities of WFCAM and VISTA and the opportunities for detailed follow-up observations on 8m-class telescopes provided by membership of ESO. Because astronomy is an observational science, rather than an experimental one, significant advances in astronomy have always relied heavily on surveys of the sky from radio, through optical to X-ray wavelengths. The new era of deep near-infrared surveys is the latest stage in this progression and is one where the UK has both a substantial lead and the necessary expertise within the Cambridge Astronomical Survey Unit (CASU) to take maximum advantage. Members of our group have long played a leading role in survey astronomy, by pioneering techniques to extract astronomical knowledge from survey data and by exploiting this information to produce world-leading research in areas such as: archaeological sifting for the fossil remnants of destroyed satellite galaxies in the Milky Way and M31; making sense of the star formation history and dark matter content of dwarf spheroidal galaxies, leftover building blocks of galaxy evolution; using redshift to directly look back at galaxy evolution over time and see how the intrinsic properties of galaxies and active galactic nucleii changes; measuring distant supernovae rates to determine the star formation history and stellar mass distribution of galaxies and to probe the dark energy content of the universe; investigating the birth and life of the smallest stars and brown dwarfs to discover how they are formed and how they evolve; searching for hot Jupiters around nearby stars and for proto-planets around newly born stars using transit surveys; CASU are also responsible for the long term development and curation of several important astronomical archives including those of the Isaac Newton Group, the UK Infrared Telescope on Hawaii, and the Anglo Australian Telescope. These legacy datasets remain valuable far beyond the initial operational and exploitation phase and are often of historical significance. Recognising this, CASU have been pioneering the use of commodity bulk storage and processing system to place these UK ground-based archives online and are developing on-the-fly calibration and processing schemes for all the raw data. Modern wide-field digital survey cameras produce torrents of data that are outside the resource capacity and analysis skills of non-specialist astronomers. By developing and operating processing pipelines and data archives CASU is enabing an optimal solution to this avalanche of data, via access to Tbyte-scale data storage and pipeline processing software and expertise. These activities are a fundamental requirement of an end-to-end integrated observing strategy and a crucial component of a global Virtual Observatory. Further in the future, GAIA, an ESA cornerstone mission scheduled for launch in 2011, will revolutionise our knowledge of the Galaxy by determining the dominant physical processes in galaxy formation and evolution. The science return derives from comprehensive datasets of a billion stars. While the full dataset, particularly parallaxes, will only be available after the mission, GAIA will also provide in real-time a multi-passband photometric sky survey with HST-class spatial resolution, and ~200 observations per source. These GAIA processing activities overlap with CASU expertise, and we propose to build on the legacy of this experience, particularly from the WFCAM and VISTA data processing activities, to help devise a real-time photometric data processing pipeline for GAIA. This will ensure UK leadership of the scientific return during the GAIA mission.


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Afonso P (2011) GRB 050502B optical afterglow: a jet-break at high redshift in Astronomy & Astrophysics

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Amanullah R (2008) Light curves of five type Ia supernovae at intermediate redshift in Astronomy & Astrophysics

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Banerji M (2013) Hyperluminous reddened broad-line quasars at z ~ 2 from the VISTA Hemisphere Survey and WISE all-sky survey in Monthly Notices of the Royal Astronomical Society: Letters

Description The key objective of the CASU programme was to provide a cost effective and timely delivery of fully processed and calibrated key WFCAM survey science data, primarily to UK astronomers but also to an international community of astronomers. This wide-field near-infrared (NIR) survey facility located on the UKIRT telescope in Hawaii, was the first dedicated NIR system specifically designed to carry out large sky surveys. It was also the precursor to the southern hemisphere equivalent, VISTA at Paranal which came into operation in 2009. The entire data flow system, known as the VDFS, was designed with the idea of developing a unified system capable of dealing with large data sets from a variety of ground-based facilities and has proven to be extremely successful.

A large part of the period of this grant was spent developing the VDFS and tuning it to deliver world-class science-ready data products for the, at the time, upcoming VISTA survey telescope. In addition CASU also developed and delivered to ESO, pipelines to run within an ESO environment on Paranal, for real time assessment of data quality,
and to Garching, for technical and calibration support.
Exploitation Route The development of robust and automated processing systems capable of routinely delivering high quality data products and detailed analyses has a
wide range of applications across several disciplines. For example, we have already initiated collaborative research projects in the medical imaging domain based on the techniques developed for astronomy.
Sectors Aerospace, Defence and Marine,Digital/Communication/Information Technologies (including Software),Other

Description The science data products are used across by a broad spectrum of the astronomical community both national and international.
First Year Of Impact 2005
Sector Aerospace, Defence and Marine,Digital/Communication/Information Technologies (including Software),Other
Impact Types Cultural

Description MoU JACH 
Organisation Joint Astronomy Centre
Country United States 
Sector Academic/University 
PI Contribution CASU undertakes data processing for all WFCAM data obtained on UKIRT
Collaborator Contribution CASU developed the data processing system and operates it on a 24/7 basis.
Impact The main beneficiary is the UKIDSS science consortium who have access to fully processed and calibrated near-infrared survey data.
Description Vista Data Flow System 
Organisation Royal Observatory Edinburgh
Department Wide Field Astronomy Unit
Country United Kingdom 
Sector Academic/University 
PI Contribution Collaborative venture to process and archive ALL data obtained on the VISTA telescope run by ESO in Paranal.
Collaborator Contribution CASU handle all the data processing and calibration.
Impact All of the VISTA public survey programmes are dependent on this collaboration.
Start Year 2009
Description Media interviews 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Multiple interviews over the years with journalists, radio and
TV media.

Year(s) Of Engagement Activity 2009,2010,2011,2012,2013
Description Talks to Astronomy Societies 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Type Of Presentation Keynote/Invited Speaker
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Talks to mainly amateur astronomy societies around the country. These are well-attended 50-100 participants and include much discussion and question/answer sessions.

Stimulates interest in science.
Year(s) Of Engagement Activity Pre-2006,2006,2007,2008,2009,2010,2011,2012,2013