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Joint Astronomy Centre Outreach - United Kingdom Infrared Telescope
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The United Kingdom Infrared Telescope

The United Kingdom Infrared Telescope (UKIRT) is one of two telescopes operated by the Joint Astronomy Centre, the other being the James Clerk Maxwell Telescope (JCMT).  UKIRT is currently in a transitional phase towards new ownership.

UKIRT on Mauna Kea.

UKIRT sees the universe with infrared light, the invisible heat radiation that lies beyond red at the edge of a rainbow. It was originally designed as a relatively simple 'light collector', but its 3.8-meter diameter mirror is of extremely high quality. Advanced upgrades to the rest of the telescope have allowed UKIRT to take full advantage of the excellent conditions on Mauna Kea.

UKIRT detects its light with a suite of advanced instruments, including WFCAM (the Wide-Field Camera) and UIST (the UKIRT Imager Spectrometer). These 'workhorse' instruments are capable of performing the three main types of infrared observations: imaging, spectroscopy, and polarimetry.

UIST was built at the Astronomy Technology Centre in Edinburgh, Scotland. On its first night at UKIRT it was used to map part of the Omega Nebula, a gas cloud where new stars are forming. Located 5000 light years from Earth, the nebula is a near neighbor in astronomical terms. The intense ultraviolet radiation from young, hot stars blasts the atoms in clouds of interstellar gas, making them glow brightly.

UIST image of Omega Nebula.

UIST also has a revolutionary 'image slicer', which slices the light from an astronomical target into thin sections. Each slice is then spread out to make a spectrum, like the rainbows produced when light passes through a glass prism. Astronomers recombine these spectra to get a three-dimensional view of the interactions between stars, cosmic dust and gas in complex objects like galaxies.

The UIST image slicer.

Shortly after UIST started observations it was trained upon the most distant quasar known, about 13 billion light years from Earth. Quasars are exceptionally luminous galaxies, far brighter than can be explained by normal starlight. They are powered by the release of gravitational energy as matter is pulled toward a supermassive black hole at their centres, and their extreme brightness makes them visible at great distances. By looking at gas swirling around the quasar's core, scientists were able to 'weigh' this black hole at the edge of the universe. It has the mass of three billion Suns!

UKIRT also studies brown dwarfs, mysterious objects sometimes referred to as 'failed stars'. They are more massive than gas giant planets like Jupiter, but are not quite massive enough to shine like normal stars. UKIRT has significantly advanced our understanding of them over the last few years.


Many such advances in recent years have been made with the newer instrument, WFCAM. WFCAM covers two tenths of a square degree of sky in a single exposure, allowing UKIRT to carry out its current extrememly ambitious survey of the infrared sky the UKIRT Infrared Deep Sky Survey (UKIDSS). Below are two images from UKIDSS.

Galactic Plane Survey Whole-Plane Mosaic (taken with WFCAM on UKIRT as part of UKIDSS).

The Sombrero Galaxy (M104, taken with WFCAM on UKIRT as part of UKIDSS).

UKIRT was opened in October 1979.

You can find some more technical information in an older article about UKIRT.

Contact: JAC outreach. Updated: Tue Dec 31 10:58:11 HST 2013

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