SCUBA-2: the 10 000 pixel bolometer camera on the James Clerk Maxwell Telescope

Abstract

SCUBA-2 is an innovative 10000 pixel bolometer camera operating at submillimetre wavelengths on the James Clerk Maxwell Telescope (JCMT). The camera has the capability to carry out wide-field surveys to unprecedented depths, addressing key questions relating to the origins of galaxies, stars and planets. With two imaging arrays working simultaneously in the atmospheric windows at 450 and 850 µm, the vast increase in pixel count means that SCUBA-2 maps the sky 100-150 times faster than the previous SCUBA instrument. In this paper we present an overview of the instrument, discuss the physical characteristics of the superconducting detector arrays, outline the observing modes and data acquisition, and present the early performance figures on the telescope. We also showcase the capabilities of the instrument via some early examples of the science SCUBA-2 has already undertaken. In February 2012, SCUBA-2 began a series of unique legacy surveys for the JCMT community. These surveys will take 2.5 years and the results are already providing complementary data to the shorter wavelength, shallower, larger-area surveys from Herschel. The SCUBA-2 surveys will also provide a wealth of information for further study with new facilities such as ALMA, and future telescopes such as CCAT and SPICA.

Dusty star-forming galaxies at high redshift

“…Submillimeter Common User Bolometer Array-2 [Scuba-2], 2011-present Scuba-2 (Holland et al, 2013) is the second generation bolometer array for the James Clerk Maxwell Telescope and finished commissioning in 2011. Scuba-2, a 10000 pixel camera with 100-150 times the mapping speed of Scuba, operates simultaneously at 450µm and 850µm.…”

Submillimetre Studies of Prestellar and Starless Cores in the Ophiuchus, Taurus and Cepheus Molecular Clouds

“…SCUBA-2 observes in two wide wavelength bands, centred on 450µm and 850µm, at effective resolutions of 9.6 ′′ and 14.1 ′′ respectively (Holland et al 2013 hence that the 450µm data is better than Nyquist-sampled.…”

“…All observations were taken using the 'PONG' observing mode (Holland et al 2013), in which the area of even coverage within the observation is maximised. This is done by defining the map as a square region and tracking the telescope across this region, 'bouncing' off the walls of the square as shown in Figure 2.6.…”

“…The 450µm and 850µm bandpass filter Figure 2.8: SCUBA-2 bandpass filter profiles at 450µm (blue) and 850µm (red), superimposed on the atmospheric transmission curve for Mauna Kea for 1mm of precipitable water vapour (Holland et al 2013). profiles, shown on the same figure, are chosen to exploit the atmospheric transmission windows.…”

“…SCUBA-2 850-µm data may be substantially contaminated by the CO J= 3 → 2 transition (Drabek et al 2012) which, with a rest wavelength of 867.6 µm, is covered by the SCUBA-2 850-µm filter -half-power bandwith 85µm (Holland et al 2013). …”