JCMT

The James Clerk Maxwell Telescope (JCMT) is the world's premier ground-based facility for astronomical observations at sub-millimetre wavelengths. This status is afforded by three essential ingredients: the size and quality of the telescope, its location, and its aggressive programme of instrumentation.

The JCMT is the largest single-dish telescope in the world designed specifically to operate in the sub-millimetre region of the spectrum (wavelength range 450µm - 1mm). The primary reflector of the JCMT has a diameter of 15 metres and its figure is maintained at an accuracy of just 22µm rms through a programme of periodic holography and panel adjustment. The facility is situated at the summit of Mauna Kea, on the island of Hawaii, at an altitude of 4092m. This is one of the best sites in the world for sub-millimetre astronomy, and certainly the very best in the northern hemisphere.

The James Clerk Maxwell Telescope (JCMT) is the world's premier ground-based facility for astronomical observations at submillimetre wavelengths. Three essential ingredients afford this status: the size and quality of the telescope, its location, and its aggressive programme of instrumentation.

The JCMT is the largest single-dish telescope in the world designed specifically to operate in the submillimetre region of the spectrum (wavelength range 450μm-1mm). The primary reflector of the JCMT has a diameter of 15m and its figure is maintained at an accuracy of just 22μm rms through a programme of periodic holography and panel adjustment. The facility is situated at the summit of Mauna Kea, on the island of Hawaii, at an altitude of 4092m. This is one of the best sites in the world for submillimetre astronomy, and certainly the very best in the northern hemisphere.

Two categories of instrument are provided for users of the facility. (a) Heterodyne receivers are available in a number of atmospheric transmission windows to measure line emission from specific molecules, revealing physical information about the source being observed (composition, temperature and velocity). (b) A new continuum camera called SCUBA-2 is being commissioned during 2010/11 and will offer simultaneous high-fidelity imaging at 450μm and 850μm.

The JCMT is a joint project of the United Kingdom (55%), Canada (25%) and the Netherlands (20%). The managing agency is the UK Science and Technology Facilities Council (STFC). The Director JCMT is responsible for the operation and development of the telescope. The JCMT Board, a governing body that is defined by the tripartite agreement between the agencies, provides oversight. The administrative base for the facility is the Joint Astronomy Centre (JAC), an STFC establishment located at sea level in Hilo, Hawaii. As a non-European country, Canada has declined to participate in the RadioNet project. Transnational access will be offered from UK and Netherlands telescope time only. The mission of the JCMT is to enable astronomical observations and to provide the resultant data products to its users. Sophisticated data reduction pipelines are provided for each instrument.

The submillimetre region of the spectrum is relatively unexplored and offers a number of unique advantages: first, it is the region of thermal emission from cold objects such as the interstellar medium, molecular clouds and the earliest stages of star formation; second, the infrared emission from extragalactic sources at cosmological distances is redshifted to submillimetre wavelengths; and third, since the interstellar medium is optically thin it is possible to probe to the interior of dust-obscured regions. The major areas of research undertaken with the JCMT are, accordingly,

• Galaxy formation and evolution,
• Star formation in the Milky Way and nearby galaxies, and
• Planet formation around nearby stars.