CamCEAD (formerly the Cambridge Astronomical Survey Unit, CASU) leads the core 4MOST Data Management System (DMS) and hosts the 4MOST Data Processing Centre (4DPC) at Cambridge, performing all Level 1 processing, integrating galactic and extragalactic Level 2 pipelines, and ensuring Phase 3 delivery of science-ready products to the ESO archive.
CAMCEAD, CASU, Institute of Astronomy, University of Cambridge
What is 4MOST?
4MOST, the 4-metre Multi-Object Spectroscopic Telescope, is a fibre-fed spectroscopic survey facility on ESO's 4-metre VISTA telescope at Paranal Observatory in Chile. It can take spectra of up to 2,400 objects at the same time across a field of 4.2 square degrees, which makes it one of the most capable spectroscopic survey instruments in the southern hemisphere. The first five-year public survey includes 10 consortium programmes and 15 ESO community programmes, and will observe at least 25 million objects over 15,000 square degrees of sky.
4MOST was designed to work alongside ESA's Gaia, Euclid and PLATO missions and the Vera C. Rubin Observatory on the ground. It provides the spectroscopy needed to follow up the objects those photometric and astrometric surveys find.
Cambridge as the 4MOST Data Processing Centre (4DPC)
CamCEAD leads the core 4MOST Data Management System (DMS) and is the 4MOST Data Processing Centre (4DPC). Cambridge is responsible for the whole production data flow: receiving the raw observations, carrying out all Level 1 reduction, bringing in the Level 2 science pipelines, and delivering validated, science-ready products to the ESO Science Archive through Phase 3.
L1 Processing
Level 1: core data reduction
All Level 1 processing for 4MOST is done in Cambridge by the DMS team, which CamCEAD leads. It covers the full nightly reduction:
- Bias, flat-field and wavelength calibration
- Sky subtraction and flux calibration
- Extraction of the spectrum from each fibre in both modes (LRS and HRS)
- Quality control and nightly checks
- Producing and managing calibration products
L2 Integration
Level 2: science pipelines
Cambridge brings together the higher-level results from the consortium's Galactic and extragalactic pipelines into consistent datasets ready for science:
- Galactic pipeline products (stellar parameters, kinematics, abundances)
- Extragalactic pipeline products (redshifts, classifications, line measurements)
- Consistency checks between surveys and tracking of provenance
- Putting together and validating the catalogues
Phase 3
Phase 3: delivery to the ESO archive
CamCEAD makes sure every 4MOST data product meets ESO's Phase 3 requirements before it goes to the ESO Science Archive Facility (SAF):
- Phase 3 file formats and metadata
- Submitting reduced spectra, catalogues and value-added products
- Making the data publicly available through the ESO archive
- Coordinating data releases across all the survey programmes
How the DMS runs operations
The 4MOST Data Management System handles everything from planning observations at Paranal to delivering data to the archive. Cambridge leads the DMS team, which is directed by Nic Walton and David Murphy, and is responsible for making the whole system work.
Observation Planning
Planning and scheduling
The DMS generates and schedules Observing Blocks (OBs) automatically. It combines the target catalogues from all survey programmes and adjusts the plan to the conditions at the site on the night. It ran nightly operations on its own during Operations Rehearsal 4 (OpR4).
Provenance and Tracking
Tracking state and provenance
The DMS records the processing state and provenance of every data product, following each observation from the raw frame to the archived science product. At each stage products are checked against the data model before they can move on.
Key milestones
Related Links
CamCEAD Collaborators
Research Associate
Research Associate
Research Associate
Research Associate
Assistant Research Professor
Senior Research Associate
Research Assistant in Astronomical Data Science
