University of British Columbia scientists have helped build the world's largest astronomy camera with an internal temperature colder than anything else in the Universe.
The 4.5-tonne SCUBA-2 (Submillimetre Common User Bolometer Array) camera, unveiled today as part of the James Clerk Maxwell Telescope at the summit of Mauna Kea in Hawaii, will survey wavelengths invisible to optical cameras and capture unprecedented information about the formation of stars.
"We're used to thinking about astronomy in terms of images made using optical light," says Douglas Scott, a professor in the Department of Physics and Astronomy at UBC and part of an international team of scientists and engineers that built the camera. "But technology has evolved to allow us to unearth vastly more information using other wavelengths of light and paint a much more revealing picture about the birth of stars."
Led by the U.K.-based Science and Technology Facilities Council (STFC), SCUBA-2 was built in collaboration with Canadian, U.S. and Dutch scientists. The UBC team, which also includes Cosmology Prof. Mark Halpern, postdoctoral research associate Ed Chapin, software engineer Andy Gibb, electronics engineer Mandana Amiri and graduate students Todd Mackenzie and Viktoria Asboth, custom-designed and constructed the electronics, enabling acquisition of data from the detectors and authored the software that translates the data into pictures.
Stars form when dust and gas clouds collapse under the weight of their own gravity. The dust in the area then absorbs all visible light, making it impossible for astronomers to capture the process using optical instruments.
Effectively, the stars hide themselves in the nurseries where they are born. But SCUBA-2 is designed to detect longer wavelengths of light - known as submillimetre wavelengths - which are re-radiated by the dust and measured in microns, or millionths of a metre, says Halpern. This allows scientists to peer inside the darkest parts of the Universe, where stars are forming in the midst of cold dust clouds they made themselves.
But in order to detect light in this range, the heart of the camera must be cooled to 0.1 degree above absolute zero (or -273.05 degrees Celsius), making the inside of SCUBA-2 colder than anything else in the Universe.
Significantly more powerful than its predecessor SCUBA, which began operation in 1997, SCUBA-2 can map areas of the sky hundreds of times faster, and is more sensitive and powerful.
"With SCUBA, it typically took 20 nights to image an area about the size of the full Moon," says Prof. Wayne Holland, SCUBA-2 Project Scientist from STFC's UK Astronomy Technology Centre. "SCUBA-2 will be able to cover the same area in a couple of hours and go much deeper, allowing us to detect faint objects that have never been seen before."
SCUBA-2 will be used to map sites of star formation within our own Milky Way galaxy, and planet formation around nearby stars. It will also be used to look deep into space and sample the youngest galaxies in the Universe, helping researchers understand how galaxies have evolved since the Big Bang. This information will help Scott and Halpern better understand the origin and evolution of galaxies throughout all of cosmic time and in particular, provide unique insights into the earliest dusty phases.
Partners on the SCUBA-2 project include the University of Edinburgh, Cardiff University, the U.S. National Institute of Standards and Technology, UBC, the University of Waterloo and the Joint Astronomy Centre (JAC). The project was funded by the STFC, the JAC, and the Canada Foundation for Innovation.
Example images, including the galaxy M51, part of the Milky Way, the Moon and the moons of Jupiter are available at:
- Size: 3m (height), 2.4m (width), 2.6m (depth)
- Weight: 4.5 tonnes
- Temperature of detectors: 0.1K = -272.9°C
- Submillimetre camera with 5,120 pixels (4 sub arrays at 1,280 pixels each) at each wavelength band
- Provides a unique wide-field submillimetre imaging capability at 450 and 850 microns (0.45 and 0.85 mm)