Thursday, March 14, 2013

McMaster gets air time at biggest telescope

With 66 antennas, many of them 12 metres across, spread out across the driest desert on earth, the Atacama Large Millimetre/submillimeter Array (ALMA) observatory is considered the world’s biggest astronomy project ever.
And, after more than 20 years of planning and building, it opened officially on Wednesday 5,000 metres above sea level in northern Chile. Several Canadians, including a McMaster astronomy professor and a PhD student, are watching closely as the facility comes online and is expected to drastically change the research capability in their field — the study of how stars are formed.
By combining the radio waves collected by several antennas it is possible to construct images. Such images are comparable to those that would be obtained with a traditional telescope or antenna, 14,000 metres in diameter.
“ALMA is going to blow this field wide open,” says professor Chris Wilson, who has been involved in the project for 15 years. “With ALMA, you have a bird’s-eye view of various galaxies ... instead of looking from within our galaxy looking out.”
McMaster astronomy PhD student Maximilien Schirm is one of 18 Canadian scientists awarded research time this year with ALMA.
Under Wilson’s supervision, Schirm will be using ALMA to observe two merging galaxies, 70 million light years away, known as the Antennae system. His project focuses on the molecular gas clouds throughout these galaxies in which stars form.
“Understanding star formation in merging galaxies is crucial to our overall understanding of how galaxies have and will evolve throughout the lifetime of our universe,” he says.
Schirm says he is thrilled to be given the opportunity.
“ALMA is one of, if not the, most powerful telescopes in the world ... It will allow us to push the limits in terms of what we can observe. At this point, the possibilities feel endless.”
Schirm’s project was part of a second round of proposals for ALMA, in which 1,133 were submitted and 196 were awarded research time.
The Canadians will be part of what Wilson calls the first “world observatory,” with scientists from North America, Europe, some parts of Asia and host country Chile using the facility for cutting-edge astronomy research.
Overall, the project cost more than $1 billion. Canada contributed more than $30 million through the National Research Council (NRC)
On Wednesday, Chilean president Sebastian Piñera and hundreds of international guests, including at least two Canadians from the NRC’s Herzberg Institute of Astrophysics, were on site to celebrate the opening.
The Atacama Desert is already home to many well-known astronomy observatories as its viewing conditions, along with those in Hawaii, are considered the best in the world for scientific study.
To the naked eye, the desert sits under a wide-open night sky, one free of light pollution and littered with a thousand stars.
“It’s just simply that it’s very high and extremely dry. And it also happens to have a very flat bit,” says Wilson, who visited the site 12 years ago with the international ALMA Science Advisory Committee when there was “almost nothing” there.
She was invited to the opening this week, but had to remain in Hamilton to teach.
However, while on a research leave later this year, she will return to Chile and spend several months to help perfect the technical aspects of ALMA — making sure data received is turned into images scientists can use.
ALMA has been receiving data from some of the telescopes already on site since 2011. Wednesday’s ceremony marked the near completion of the project.
Wilson says already some of the most remarkable images have come out of the data, including one of a dying star with a spinning spiral around it.
It was the first time a telescope has detected the material within a star’s outer shell, she says, meaning the star’s process of shedding its layers was ongoing.
“I just think it’s visually very cool,” Wilson adds.
An extremely large transporter moves the many telescopes around on site and much of the research can be done remotely, as is often the case with new, large telescopes.
“[Astronomy] is always exciting,” Wilson says, “but I have to say the last five or six years have been particularly exciting. And the next decade promises to continue that.”
In addition to the inauguration of the ALMA, the Very Large Array observatory in New Mexico was recently upgraded, and several record-breaking, large projects are in the works: the European Extremely Large Telescope, set for northern Chile, the Thirty Metre Telescope, planned for Hawaii, and the James Webb Space Telescope, the eventual successor to the Hubble Space Telescope.

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