'Dark energy' camera captures first images of the universe
Share
-
Globular star cluster 47 Tucanae, which lies about 17,000 light years from Earth.Dark Energy Survey Collaboration
A giant astronomical camera designed to help scientists study ‘dark energy’ has captured its first images of the universe.
The telephone-box-size 570-megapixel Dark Energy Camera, built with the help of UK scientists at a mountaintop observatory in Chile, can capture light from more than 100,000 galaxies up to eight billion light-years away in each shot.
An international team of researchers plans to use the camera to study the layout of galaxies in order to better understand a mysterious phenomenon known as ‘dark energy’, which is thought to explain why the expansion of the universe is speeding up.
Prof Ofer Lahav from University College London (UCL), who heads the UK consortium for the Dark Energy Survey (DES), said in a statement: ‘The achievement of first light through the Dark Energy Camera brings us a step closer to understanding dark energy, one of the biggest mysteries in the whole of physics.
‘The deep observations with the DES camera will tell us why the universe is speeding up and if a major shift is required in our understanding of the universe.’
The camera, whose construction was supported by the UK Science and Technology Facilities Council (STFC), uses an array of 62 charged-coupled devices that are highly sensitive to red light, together with the 13ft light-gathering mirror at the Cerro Tololo Inter-American Observatory, to make detailed images of the night sky.
It will enable the survey team, which is led by the US government’s particle physics centre Fermilab, to study galaxy clusters, supernovae, the large-scale clumping of galaxies, and weak gravitational lensing (the way gravity bends light) — the first time these four phenomena have been examined in one experiment.
Dark energy is a hypothetical form of energy thought to make up around 75 per cent of all the matter and energy in the universe. Because it is impossible to see directly, scientists hope to be able to learn more about it by studying how it affects other phenomena.
Plymouth University’s Prof Will Percival, who co-coordinates the galaxy clustering of DES, said: ‘This will be the largest galaxy survey of its kind, and the galaxy shapes and positions will tell us a great deal about the nature of the physical process that we call dark energy, but do not currently understand.’
Cambridge University’s Prof Richard McMahon, another researcher in the UK team, said: ‘The construction of a three-dimensional map of the galaxies just based on their positions and optical colours is extremely challenging and will require sophisticated computational and statistical techniques.
‘The addition of galaxy near-infrared colours from another UK-led sky-mapping survey — the VISTA Hemisphere Survey — will greatly improve the accuracy of the map.’
The survey is expected to begin in December once the camera is fully tested. Over five years, it will create detailed colour images of one-eighth of the sky — or 5,000 square degrees — to discover and measure 300 million galaxies, 100,000 galaxy clusters, and 4,000 supernovae.
In addition to STFC’s contribution, DES is supported by funding from the US Department of Energy, the National Science Foundation, and funding agencies in Spain, Brazil, Germany and Switzerland, as well as the participating DES institutions.
Readers' comments (8)
Ron Saunders | 18 Sep 2012 2:26 pm
I'm confused.
Didn't Einstein theorise that time slowed down near the speed of light?
I'm not a physicist but it occurs to me that if time slows down near the speed of light as these distant objects are, then won't they just appear to be going faster even though they're not?
If this is the case then there is no need for the dark energy theory.
It seems that time has already slowed down anyway. At the start of the universe everything happened at once but now clearly it doesn't. If time continues to slow down then won't it stop at some point in the future? If time stops then won't everything happen at once again?
Will somebody please enlighten me, a simple office manager?
Unsuitable or offensive? Report this comment
Editor's comments | 18 Sep 2012 2:26 pm
Einstein said that time slows down *for the observer* as they travel near the speed of light.
JohnK | 18 Sep 2012 3:38 pm
I've often wondered ... Let us take as a stated fact that 'The farther an object is from earth the older it is'. So, If we go back 13.something billion years we arrive at the singularity that was the Big Bang. If so, then surely the farther we look back in time, the more such objects must be contained in a smaller and smaller sphere of matter nearer that singulartity point so that we should, in effect, be looking in only one direction for all these really old items, but all the articles seem to say the universe is equidistant all around us at all times, including the distant past. (Is earth really the centre of the universe?). I understand that as part of the 'sphere of influence' started by the big bang, we are encompassed by and are part of 'our' universe, but way back toward the beginning, why should it still be so far away and all around. That's what makes me wonder.... and I must confess, a bit confused.
Unsuitable or offensive? Report this comment
Stephen Mosley | 18 Sep 2012 4:17 pm
I think you will find that it's all relative.
Unsuitable or offensive? Report this comment
Jorrie | 18 Sep 2012 10:02 pm
It was not that far away originally; that light we now see from the CMB originated only 42 million light-years away, all around us (or at least around here where we later 'surfaced'). Because of the expansion, it took 13.7 billion years to reach us.
And yes, we are indeed at the center of our observable universe ...
Unsuitable or offensive? Report this comment
CJS | 19 Sep 2012 2:59 am
JohnK. I too wondered about the exact same thing. The closest explanation I got is that, it is same as the earth. Any place you stand on the earth can be the center because if you look out into the horizon, and start walking, more opens in front of you. But your horizon remains approximately the same. Hence, the farthest distance you can go from any spot on the earth is roughly the same. So, from anywhere in the universe, the farthest light will be 13 odd billion years old.
Unsuitable or offensive? Report this comment
Mike Blamey | 20 Sep 2012 5:08 am
How splendid that our minds, as Engineers and even plain old simple 'office managers' (no offence intended) can be stretched by the concepts/ideas being discussed here. How wonderful that we have a forum for the uninhibited advance of our thinking and thence the ascent of mankind. We, who have the privilege of training and/or interest in matters technical and scientific, constantly look forward with inspiration: there are other groups, sadly (for us) they still hold pivotal power within our society yet spend most of their time looking backwards for precedent. At a time when I gather 70% of ALL those who have ever been scientifically (as opposed to artistically) trained are present and active upon our small planet, isn't it time we took centre stage!
Best
Mike B
Unsuitable or offensive? Report this comment
JohnK | 20 Sep 2012 1:25 pm
Mike B. I totally agree, but Engineers will firstly need to learn to sing and dance. Only this will attract sufficient attention in this relentlessly 'artistic' world to raise their profile.
Unsuitable or offensive? Report this comment
Jerry Karlin | 25 Sep 2012 2:33 pm
I agree with JohnK and MikeB in a suitably light-hearted way, but I feel i have to point out that in this particular context, complaining about looking backwards is er, far fetched! If anything we technocrats are looking for precedents billions of years further back than those Mike accuses! Let's face it (sic), inspiration can come from anywhere on our event horizons! :)
Unsuitable or offensive? Report this comment