Delivery of DECam on the Horizon

The Dark Energy Camera (DECam) is a new 520 megapixel CCD imager being built for the CTIO Blanco 4-m by the Dark Energy Survey (DES) Collaboration. The Collaboration consists of more than 120 scientists from 12 US institutions plus international consortia located in Brazil, Spain, Germany, and the UK. DECam will be available for use by the astronomical community as a facility instrument. It will also be used to carry out the DES, requiring 30% of the observing time on the Blanco for five years for this purpose. DECam and DES are described in detail at http://www.darkenergysurvey.org.

The delivery of DECam is now only months away, with installation and commissioning expected to occur in 2011B. Some components, such as the F/8 mirror handling system, have already arrived on Cerro Tololo, and work continues apace at Cerro Tololo (telescope and facility preparation), Fermilab (DECam testing), University College London (optical corrector integration), and at the National Center for Supercomputing Applications (pipelines). Of particular note is the successful production by LBNL (Lawrence Berkeley National Lab) of the 62 2Kx4K red-sensitive CCDs needed for the focal plane.

DECam is now in an intensive integration and test phase on the Blanco telescope simulator at Fermilab, as the procurement and construction phases come to completion. The new prime focus cage, hexapod mounting system, filter changer, shutter, together with DECam and its full electronics and cryogenic system will be intensively tested for a three month period ending in February 2011. The instrument software, which is being developed at U. Illinois, Ohio State University, and the Stanford Linear Accelerator Center, will be thoroughly exercised as part of the simulator tests.

The expected science return from DECam, both for the DES Collaboration and for the community, is high. With DECam potentially available for DES and community use in 2012, we encourage interested members of the community to contemplate how DECam observations may be used to advance their own science goals.

Upcoming opportunities to learn more about DECam include special sessions at the January AAS meeting on “The Dark Energy Survey” and “Community Use of the Dark Energy Camera on the CTIO Blanco 4-m Telescope”. Questions about these sessions, and about DECam and DES in general, may be directed to Alistair Walker (awalker@noao.edu). In future issues of Currents, we will advertise additional opportunities to learn about DECam and DES.