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Powerful camera seeks snapshots of dark energy

posted 8 Nov 2012, 09:07 by Mpelembe   [ updated 8 Nov 2012, 09:08 ]

The most powerful sky-mapping camera ever built is to be officially dedicated in a ceremony on Friday (November 9) at the Cerro Tolo Inter-American Observatory innorthern Chile. The camera is designed to probe deep into the universe as scientists try to solve the the mystery of so-called dark energy and its impact on the accelerating expansion of our universe.

CERRO TOLOLO, LA SERENA, CHILE  (REUTERS) -  High in the rarified air of the northern Chile's Andean region, one of astronomy's newest and most sophisticated toys has begun to probe mysteries of our universe.

This is the Dark Energy Camera, the most powerful sky-mapping machine ever created. And from its perch at the Cerro Tololo Inter-American Observatory (CTIO), the camera is starting to probe some eight billion light years into space.

Astronomer David James says the camera, as the name indicates, is out to reveal and explain the hypothetical dark matter, which scientists believe is influencing the expansion of the universe.

"This is the largest optical imager in the world, the largest camera, it has five hundred and seventeen million pixels, and it's able to survey about six times the area of the full moon in one exposure. And we're specifically looking for signatures of dark energy, that's to say, the differential expansion of the universe, the acceleration of the universe," James said.

The 570-megapixel camera, the world's powerful digital lens, was designed and built over eight years by scientists, engineers and technicians from three continents.

About the size of a telephone booth, the camera was built at the US Department of Energy's Fermi National Accelerator Laboratory in Illinois before being brought to Chileand mounted on a telescope here.

Chris Smith, the astronomy director at the Cerro Tololo observatory, showed some of the first pictures taken by the camera, test images captured in September.

"The significance is this camera that we've built and that we've recently installed and turned on the CTIO 4-m telescope will allow us to go much deeper and to understand the aspects of the universe with much more precision than we were able to do in between 1998 and today, and that should allow us to probe and to understand this mystery of the universe which in reality makes up for 70% of our known universe, so it's a huge part of the universe which we don't understand and that we're trying to get a handle on, with starting surveys, starting projects using this camera," Smith said.

The first images from the camera show the Formax galaxy cluster, which sits some 60 million light years from earth.

James says the camera not only allows a deeper view into space, but also a wide field of vision. This will allow astronomers to compare larger images over the years and hopefully gain knowledge of how our universe is changing.

"So, the camera is revolutionary in the sense that it can survey large areas of the sky in one exposure, but also can go to great depths, but great optical depths, we can image a very great distance in the universe, but also in measuring this thing called dark energy which is a very difficult thing to explain and what Einstein have in his original general relativity equations, and so this really is fundamental astrophysics, but It's not like the old days where you go to the telescope and take an image, and move to take another image and you have to survey the sky very very slowly, now we're able to take images of large parts of the sky, and repeat those observations many times over many years, so that we can build a very complicated but detailed picture of the universe," James said.

From the images captured in September, astronomers showed they can take larger pictures of the Formax cluster and then pan in on a galaxy. The galaxy seen here is NGC 1365, part of the Formax cluster.

The issue of dark matter and its possible role in the expansion of the universe is among astronomy's biggest mysteries.

Because of this, Smith says, the Dark Energy Camera has generated a buzz in the scientific community.

"When we discovered it in '98, and since then there's been a great interest in what this mysterious force could be, both scientific and public, and so people had been following the reports and following our studies, our investigations of this effect, and so the interest that has been generated around turning on this camera, and installing and starting a new phase in the investigation of this, really shows that that interest, that fascination with our community's still there and continues to tap a fundamental, a core question that all of us have: 'what is the universe made of?' and 'what is the destiny of the universe?'. Those are the questions that we're investigating with this camera and with are trying to understand our energy," the astronomer said.

After taking some more test images, the camera is expected to carry out a five-year study -- the Dark Energy Survey -- starting in December.

Astronomers hope this study yields colour images of one-eighth of the sky and plan on discovering and measuring some 300 million galaxies and 4,000 supernovae.