The following is a rather short summary. Please refer to the 4MOST website here and here for more detailed information.

A survey can be participating or non-participating. Participating surveys share the focal plane (parallel observing mode) and are members of the Science Team. Non-participating surveys do not share the focal plane and do not have access to the science team know-how. Once accepted for execution within the 4MOST Survey Programme there is no difference between community and consortium surveys at the operational level.

Participating community surveys: they will be executed in parallel observing mode with the GTO surveys. This requires:

  • Common observation preparation
  • Common selection function computation
  • Cross-talk on CCD, sharing of 1D spectra
  • Sharing of the advanced (L2) data products and analysis pipelines

Non-participating community surveys: they will NOT be executed in parallel observing mode with any other 4MOST survey.

  • OBs will be prepared by the 4MOST Consortium and/or the consortium will deliver and maintain the tools to prepare the OBs
  • Raw data will be reduced by the 4MOST Consortium and1D calibrated spectra delivered to the PIs.

When submitting their Letters of Intent (LoIs), community PIs should declare if their surveys have to be considered participating or non-participating.