New telescopes peer back to birth of first stars

New telescopes peer back to birth of first stars - A new network of telescopes will allow astronomers to peer deeper into space than ever before, enabling them to see the first stars and galaxies in the universe being born.

Using a new type of telescope, which detects low-frequency radio signals coming from outer space, scientists claim they will be able to see deeper into space, and so view events that occurred further into the universe's past due to the time it takes for the radio waves to reach Earth, than has previously been possible.

A network of 77 of these new telescopes is being built across Europe and will be combined with two other radio telescopes in the southern hemisphere to give an unprecedented view of the heavens.


http://i.telegraph.co.uk/telegraph/multimedia/archive/01795/galaxy_1795430c.jpg
This image show the immense Andromeda galaxy
Photo: AP/NASA


Astronomers hope to find clues that will help them unravel how the first stars and galaxies formed from the cloud of cool gas that made up the universe after the Big Bang.

The telescopes will also allow astronomers to sweep large sections of the sky in single nights and so increase the chances of spotting previously unseen objects in space.

Professor Rob Fender, an astronomer at the University of Southampton who is leading the project, said: "Detecting low-frequency radio waves means we can look deeper into space than has ever been possible before and means will be able to conduct the first studies of a time known as the epoch of re-ionisation.

"This was when the universe moved out of its so-called dark ages in the first billion years after the Big Bang and the first stars and galaxies began to form.

"By looking this far back we can hopefully find out more about what caused this to happen and what these early parts of the universe looked like.

"Low-frequency radio waves allow us to see through the inter-stellar gas that obscures much of the most distant parts of the universe, so we will be able to detect the most distant galaxies."

According to the present theories about the early universe, the Big Bang created a soup of primordial matter that gradually cooled over a million of years, leaving the universe dark and cold.

After several hundred million years, the first atoms began to form and gave birth to the first stars and black holes. The light from these created energy that resulted in a chain reaction of creation through the universe.

Radio waves are created by large, violent events in space such as exploding stars and black holes, which fling out huge amounts of energy.

By looking for this energy from deep in space, astronomers hope they will be able to see some of the first stars and galaxies being formed.

Radio telescopes are already used to detect high-frequency radio waves that come from space and enabled the discovery of pulsars and quasars.

Low-frequency radio waves, however, can travel much further through space than those currently detected by the array of radio dishes used by astronomers, so the new network of detectors, called Lofar (or low-frequency array) will allow astronomers to see some of the most distant objects in the universe.

Construction on the first Lofar telescope in the UK has just been completed in Chilbolton, Oxfordshire, while there are plans to build another four in Edinburgh, Cambridge, and at Jodrell Bank outside Manchester.

There are another 48 already built or near-completion elsewhere in Europe.

The low-frequency telescopes consist of a series aerials set up in fields across Europe, with the first having being built in the Netherlands.

Computer software helps to filter out background radio signals from televisions and terrestrial radio broadcasts while also allowing astronomers to focus the telescopes onto areas of the sky.

When complete, data from 15,000 aerials across Europe, including from the UK, Italy, France, Germany and Sweden, will then be fed to a central hub in the northern Netherlands before being analysed by astrophyscists.

Another radio telescope being built in the Northern Cape of South Africa, called MeerKat, will also allow the astronomers to monitor the sky in the southern hemisphere along with a further radio telescope called Aakap in Western Australia.

These two telescopes will operate at higher frequencies and provide astronomers the option of looking in more detail at objects found using Lofar.

Professor Fender, who has received £3 million of funding from the European Research Council to co-ordinate the collaborative project, which has been named 4Pi Sky, said: "Low-frequency radio surveys also allow us to cover large amounts of the sky at any one time.

"Rather than taking months to sweep the whole sky, we will be able to do it in a matter of days.

"As we will be looking in frequencies that have not been explored before, there is also the chance we will make some unexpected discoveries. This has happened in the past when people started using X-ray and microwave detectors."

Dr Robert Massey, from the Royal Astronomical Society, said: "This is a fantastic example of a project where international collaboration is needed to see truly distant objects far more sharply than could have been possible before.

"It should help answer some very important questions about what happened after the Big Bang to result in the stars and galaxies we have around us today."

Lord Martin Rees, the astronomer Royal and a professor of cosmology at the University of Cambridge, added: "Lofar is the first of these next generation telescopes and a pre-cursor to the Square Kilometre Array, which will spread have a huge collecting area.

"Telescopes like this can help to produce a three-dimensional map of the ionised and unionised hydrogen in the universe, which is a rich source of information about what happened during these early stages of the universe when the cosmic dark ages ended and the first stars formed to light the universe up again." ( telegraph.co.uk )

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