The UKIRT wide-field camera

¹ European Southern Observatory, Karl-Schwarzschild Str.2, 85748, Garching bei Muenchen, Germany e-mail: mcasali@eso.org
² Joint Astronomy Centre, 660 N. Aohoku Place, University Park, Hilo, Hawaii, 96720, USA
³ School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
⁴ UK Astronomy Technology Centre, Blackford Hill, Edinburgh, EH9 3HJ, UK
⁵ Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh, EH9 3HJ, UK
⁶ Institute of Astronomy, University of Cambridge, Madingley Rd, Cambridge, CB3 0HA, UK
⁷ Subaru telescope, National Astronomical Observatory of Japan, 650 N.Aohoku Place, Hilo, Hawaii 96720, USA
⁸ Astrophysics Group, Imperial College London, Blackett Laboratory, Prince Consort Rd, London, SW7 2AZ, UK

Received: 6 October 2006
Accepted: 20 February 2007

Abstract

Context.The infrared wide-field camera (WFCAM) is now in operation on the 3.8 m UK Infrared Telescope on Mauna Kea. WFCAM currently has the fastest survey speed of any infrared camera in the world, and combined with generous allocations of telescope time, will produce deep maps of the sky from Z to K band. The data from a set of public surveys, known as UKIDSS, will be initially available to astronomers in ESO member states, and later to the world.

Aims.In order to maximise survey speed, the WFCAM field of view was required to be as large as possible while incorporating conventional infrared-instrument design features such as a cold re-imaged pupil stop and cryogenic optics and mechanisms.

Methods.The solution adopted was to build a cryogenic Schmidt-type camera, mounted forward of the primary mirror, which illuminates a very large 0.9° diameter focal plane, containing four 2k  2k HgCdTe Rockwell detectors.

Results.Following several commissioning periods during which the camera, focal plane and telescope optical axes were successfully co-aligned, WFCAM now operates close to specifications, regularly achieving 0.7´´ FWHM images over the full field. Projects which already report excellent results include the detection of variability in young stellar clusters, as well as preliminary deep IR imaging of the Subaru and XMM-Newton deep field.