Implementation of the survey programme

The current document is intended to make the science case for the UKIDSS survey, and not to address its practical implementation. There are obviously some non-trivial issues here, which have been partly addressed by earlier papers to the UKIRT Board, and will be the subject of more detailed papers in the near future. For context, however, we add some brief words of explanation here.

The UKIDSS proposal is made in the context of WFCAM being a funded instrument under construction, including operational software and so on. The proposal is also made in the context of WFCAM being operated within a fully operational telescope environment, supplied by the Joint Astronomy Centre (JAC). Thus we can assume that routine maintenance of the instrument is the obligation of JAC, not the UKIDSS consortium.

The implementation of the survey in terms of actual night-time operations carries a mixed obligation. The UKIDSS consortium will design the survey strategy, i.e. tiling algorithm, adaptive scheduling, and so on. Operation at the telescope will be shared between JAC and UKIDSS, being undertaken by a mixture of JAC staff astronomers, TOs, and visiting UKIDSS staff members and PDRAs. We anticipate that UKIDSS PDRAs will visit for extended periods, accommodated in an apartment provided by JAC.

The next step down the chain is pipeline reduction - removing instrumental signatures, photometric and astrometric calibration, stacking and mosaicing, and source extraction. This entails very considerable software development and operational effort but is not primarily the responsibility of UKIDSS. Rather, a collaboration between JAC, the Cambridge Astronomical Survey Unit (CASU) and the Edinburgh Wide Field Astronomy Unit (WFAU) already have an agreement to provide a standard pipeline analysis service for all WFCAM data regardless of whether from UKIDSS or PATT open time. This effort is funded within the current PPARC business plan line for wide field astronomy, and a preliminary plan has gone before the Wide Field Astronomy Panel (WFAP). The UKIRT Board will obviously want to view and approve these plans, but it is not appropriate to discuss them in detail here. It is also clear that UKIDSS will need visibility of these plans and will provide extensive advice on the detailed service, and will set functionality and performance goals on the service in order to satisfy UKIDSS requirements. Finally UKIDSS members will be expected to be involved in quality assurance, in refining photometric and astrometric calibrations, and source extraction algorithms, as their performance becomes clear as scientific results emerge.

The key role of UKIDSS members will of course come downstream of this point, in analysis of the resulting databases. This in turn will rely on datamining hardware and software tools intended to be put in place by the AstroGrid project, recently approved.