Cambridge Astronomical Survey Unit (CASU) (2023-2026): Powering Next Generation Survey Analysis and Processing

Observational survey astronomy is powering discovery, with the UK leading and benefiting from its investment, both financially and intellectually in state-of-the-art observational facilities. The last decade has seen the delivery of comprehensive imaging of both the northern and southern hemispheres in the near infrared using WFCAM and VISTA, with the UK leading these survey initiatives. These have and will provide key insights across a wide range of astrophysics. The next decade will witness the arrival of large scale spectroscopic surveys to probe in more detail key populations (be they galaxies, stars, asteroids) revealed by the imaging surveys. The UK is well poised to lead this scientific discovery, through involvement and definition of the specific surveys to be carried out on these facilities such as WEAVE, 4MOST and MOONS.

The 2020s are beginning to fulfil its potential to be the decade of "total" survey astronomy enabling profound insights into astrophysics at all scales through the combination of comprehensive imaging and spectroscopic scale data. Ensuring the scientific potential of these facilities and surveys requires the availability of expertise and systems to optimally extract information from the data. Here the UK has a substantial lead with the Cambridge Astronomical Survey Unit (CASU) and its proven ability to provide cost effective data systems to the UK and wider communities.

CASU have been at the forefront of survey astronomy, not only in pioneering techniques to optimally extract knowledge from survey data, but also in taking a proactive role in exploiting this information to produce world-leading research. This synergy and feedback between data processing and science delivery has been repeatedly demonstrated to be essential in ensuring delivery of the best possible science data products for exploitation by the widest community of UK and European astronomers. In the last decade, CASU generated science data products from VISTA, WFCAM and VST imaging and Gaia-ESO VLT spectroscopy have supported world-class research programmes across almost every UK institute involved in astrophysics. CASU are filling the astronomical data lake, the vital data resource which the community can mine, combine with other multi-wavelength data (e.g., Euclid, PLATO) and discover rare and unique objects for further detailed study by facilities such as the ELT or the JWST.

The role of CASU is acknowledged in the wider context, with ESO relying on CASU to provide the science data products from its public surveys currently running on the ESO survey facilities: VISTA, the VST and its large spectroscopic surveys. CASU's provision to ESO will extend into the next decade supporting the delivery of the science data from ESO's new front line spectroscopic survey machine: 4MOST, and for the public survey programme envisaged for MOONS on the VLT.

This grant proposal builds on the tremendous advances already made by CASU and requests funding for the period 2023-2026 for the following activities:
- WP1: Design and development of the data management and analysis systems for the next generation of ESO / ING wide field massively multiplexed optical spectrographs WEAVE, MOONS and 4MOST;
- WP2: Full operations of the WEAVE, MOONS and 4MOST pipelines, and responsibility of the delivery of the processed data products for release
- WP3: Final maintenance, operation, post operation releases and user support of the science and analysis pipelines for the UK-led VISTA large scale surveys;
- WP4: Deployment and operations of all CASU pipelines at the CASU-Data Processing Centre, itself hosted on the STFC IRIS Cloud Infrastructure

In summary, support of the CASU programme ensures the UK pre-eminence in astronomical data analysis. CASU provides the high-quality science data products from significant UK investment in frontline spectroscopic facilities, vital in maximising the research impact for the UK astronomical community.