http://www.gemini.edu/media/images_2003-2.html

The new instrument, the Altair adaptive optics system, captures three (3) times more detail in infrared light than the Hubble Space Telescope (HST) and will give astronomers a new capacity to see through the dust that blocks optical light and look into the heart of star formations. With this improved visibility, astronomers may soon be able to peek into stellar nurseries, or watch the birth of galaxies that formed 10 billion years ago.

The Altair system, built in Victoria, British Columbia by the National Research Council Canada (NRC) Herzberg Institute of Astrophysics (NRC-HIA), corrects images to compensate for the distortion caused by turbulence (mixing of warm and cold air) in the earth's atmosphere. Altair is seen as a significant improvement over other adaptive optics systems and a major boost to the performance of the Gemini North Telescope.

"This is a powerful demonstration of the instrumentation expertise in Victoria," said NRC President Dr. Arthur Carty, noting that the achievement builds upon a long list of successes in innovative technologies and Canadian contributions to the Gemini project. "We are extremely proud of the work of NRC-HIA and its partners and join them in celebrating this achievement today."

Watching galaxies being born

One of the big questions facing the international astronomy community today is how stars and galaxies form. While the Hubble Space Telescope (HST) provides excellent high-resolution images, Gemini coupled with Altair will be able to capture infrared images of fainter, hence more distant, galaxies with three times the resolution. Astronomers also need to study the spectra of distant galaxies to understand what is happening within them.

The Gemini Observatory's light gathering power (10 times that of the HST) combined with the extra resolution provided by the Canadian-built Altair, will allow Gemini's infrared spectrographs to study the inner workings of galaxies in depth.

"So now Hubble becomes our finding chart, and Gemini does the physics on what Hubble sees," says Dr. Matt Mountain, Director of the Gemini Observatory. "For the very first time, we can look at gas swirling around the nuclei of black holes. We can get our first glimpse of how early mass assembled to form today's galaxies."

Another much-anticipated use of Altair is the search for planets outside our solar system.

"Altair will give Canadian astronomers the potential to search for and image a planet around a nearby star," says Dr. Harvey B. Richer, Canadian Gemini scientist and a professor at the University of British Columbia's (UBC) department of physics and astronomy. "A lot of people have been waiting for Altair so they can do this."

A first for Canada

NRC-HIA has a history of leadership in building instruments that improve telescope performance. Recently, NRC-HIA scientists worked with partners in the United Kingdom (U.K) to build the very successful GMOS (Gemini Multi-Object Spectrograph) instruments that will allow both Gemini Telescopes to obtain spectra of hundreds of objects simultaneously, rather than one at a time. More than a decade ago, working with partners in France, NRC-HIA staff developed a pioneering adaptive optics system (PUEO) for the Canada-France-Hawaii Telescope (CFHT), also on Mauna Kea.

But Altair represents the first time that the Canadian team at NRC-HIA has built a complete adaptive optics system on its own. NRC-HIA did all of the design and construction, the optics, mechanics, software, electronics, and put them all together.

Altair produced its first high-resolution image only a few hours into its first night on the telescope. "The fact that Altair worked right out of the box is a significant technical achievement for the team," says Dr. Jean-Pierre Véran, Altair instrument scientist. "The simple user interface we use to control Altair hides the extremely complex software developed by our programming team".

"Besides coordinating the motion of more than 20 motors, the software also changes the shape of the active mirrors 1000 times a second, says Jennifer Dunn, Lead Software Engineer. Spreading these functions over multiple processors and making them work in unison was a real challenge"

"We had strict limits as to the volume, centre of gravity and interfaces," says Dr. David Crampton, leader of the NRC-HIA Advanced Technology Research Group in Victoria. "This is a high-precision instrument, we worry about things flexing by microns - a thousandth of a millimetre."

Overcoming these challenges required a talented multidisciplinary team that understood the needs of scientists, something for which NRC-HIA is well known.

"NRC-HIA is a very innovative group and it has been a great partner in the Gemini endeavour," says Mountain. "They're very good at bringing together astronomers and engineers to design products that deliver great science. It's that partnership between science and technology that brings excellent results."

The next step in adaptive optics

Canada's Altair improves on previous adaptive optics systems in several ways. First, the area of the sky that is sharpened will be larger than before. This is possible because Altair corrects high-altitude turbulence - approximately 6.5 kilometres above the telescope. Studies have shown that most of the atmospheric turbulence above Mauna Kea is at this altitude. By focusing on the area of greatest turbulence, Altair can correct the image for a larger area of the sky.

Second, Altair captures more light than previous systems. "It transmits about 90 per cent of the infrared light, which is much higher than any other adaptive optics system," says Glen Herriot, Altair project manager. "This makes the sensitivity for astronomical objects much higher."

Third, Altair is easier to use than earlier systems, which often require a team of experts to run. Astronomers will be able to view more objects each night, and concentrate on what they're seeing rather than how to use the equipment. "It really is a one-button instrument, that adjusts itself for changing weather conditions," says Herriot.

In addition, Altair can feed the corrected images to one of several instruments available on Gemini North, which expands the range of scientific problems that can be investigated.

"Altair makes corrected light available to the entire community of astronomers," says Mountain.

About Gemini

The Gemini Observatory consists of twin state-of-the-art 8-metre telescopes that are located in each hemisphere in order to provide complete sky coverage. The Gemini North Telescope is located on Hawaii's Mauna Kea, and Gemini South is located on a mountain in the Chilean Andes.

The Gemini partnership consists of the United States, United Kingdom, Canada, Australia, Argentina, Brazil and Chile. Astronomers from each partner country can apply for time on Gemini regardless of institutional affiliation and time is awarded in direct proportion to each country's contribution to the partnership.

Background information:

More information on how Altair works can be found at: http://www.hia-iha.nrc-cnrc.gc.ca/media/2003-06-02a_e.html