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The SCUBA HAlf Degree Extragalactic Survey

Data Products

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The Instruments


The James Clark Maxwell Telescope is located close to the summit of Mauna Kea, Hawaii, at an altitude of 4092 metres. With a diameter of 15 metres, it is the largest astronomical telescope in the world designed to operate at submillimetre wavelengths. More information about the JCMT is available at the JCMT home page.
The JCMT from the outside
The JCMT which housed the SCUBA and AzTEC instruments.


The Submillimetre Common User Bolometer Array was a submillimetre continuum array receiver which operated at the JCMT between 1997 and 2006. SCUBA was composed of two arrays of bolometers that viewed the same 2.3 sq. arcmin of sky simultaneously, a long wave array of 37 bolometers used at 850μm and a short wave array of 91 detectors used at 450μm. SCUBA's original design allowed for observations also at 350, 750, 1100, 1300 and 2000 microns, but due to engineering problems which began in 1997, these windows were not used. The beam size was ∼15 arcseconds at 850μm and ∼7.5 arcseconds at 450μm. The pixels were arranged in a hexagonal pattern, with the feedhorns close-packed. The bolometer performance improved with decreasing temperature, so SCUBA had a helium cooling system to cool it to below 100mK to improve detector sensitivity. Thermal noise from the sky and local surroundings dominates at millimetre wavelengths. More information about SCUBA is available at the SCUBA home page.
The SCUBA instrument in the lab
The SCUBA instrument


Astronomical Thermal Emission Camera (AzTEC) is a 144-pixel millimeter-wavelength camera that operates at either 1.1mm or 2.1mm. Radiation is coupled to Si-Ni "spider-web" bolometers, arranged in a close-packed hexagonal pattern, with an array of conical feedhorns separated by 1.4 fλ. Scanning of the telescope or movements of the secondary mirror provide fully-sampled images.
The detector array is cooled to ~250 mK via a three-stage, closed-cycle 3He refrigerator. The field-of-view of AzTEC on the LMT is 2.4 sq. arcmin and, with a per pixel sensitivity of ~3 mJyHz-1/2 and FWHM beam-size of 6 arcsecs at 1.1mm, AzTEC has an extremely fast mapping-speed of ~0.36 deg2 /hr/mJy2.
AzTEC was successfully installed and commissioned at the JCMT in June 2005, and undertook an extensive program of guest observations on the JCMT in November & December 2005 on behalf of the SHADES project. More information about the instrument is available at the AzTEC home page.

The AzTEC instrument
The AzTEC instrument.
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