Telescope may penetrate 'dark ages'

 

NETWORK:WE WILL soon be capable of seeing to the outer edges of the universe, searching for the first stars and galaxies that formed, with a powerful telescope that may be able to penetrate even further to the “dark ages” – a time without light before stars appeared.

The Square Kilometre Array (Ska) is a €1.85 billion project to build the largest radio telescope network yet assembled. These telescopes will not use mirrors and lenses to capture light; instead they use dishes and other devices that read incoming radio waves in order to “see” the stars.

Dr Michiel van Haarlem, interim director general of the Ska Organisation, discussed the project at the Euroscience Open Forum in Dublin, which came to a close yesterday.

It involves installing thousands of dishes and other receiving equipment across thousands of kilometres, with two main locations involved – South Africa and Australia. “They add up to a rather impressive array,” Dr van Haarlem said, with some understatement.

The Ska Organisation was established in 2011 with its headquarters in Manchester. It involves nine countries, with India expected to become a full member before the end of the year, he said.

The Ska will be 50 times more sensitive than existing radio telescopes and will be reading weak radio waves that flow towards us from all directions. These originate in stars and galaxies and from past cataclysmic events, such as stellar explosions.

The fact that the 6,500 dishes and receivers are spread out over such great distances is what will give the telescope its sensitivity, said Dr van Haarlem. It will be built in two phases, the first completed by 2020 and the second by 2024.

The scientific discoveries it could make are staggering, with several major goals, the first being to find the first stars and galaxies that formed after the Big Bang, said Dr van Haarlem. Related to this was a possible glimpse into the darkness before the first stars began to show, the so-called dark ages.

Another is looking for “gravitational radiation” by using pulsars and black holes. Dr van Haarlem included studies of massive magnetic fields identified around the fringes of galaxies. Scientists have no idea of how they form or why they are there.

The search for extra-terrestrial life is also included, he added. The massive telescope will be able to pick up signals from distant alien worlds, provided they exist.

Ireland is also trying to become involved in radio astronomy, not on the scale of the Ska but in a way that still delivers good science. Prof Peter Gallagher of Trinity College Dublin is heading an all-Ireland consortium attempting to build a world-class radio telescope in Birr, Co Offaly.

The project is called I-Lofar, the Irish Low Frequency Array. For an investment of €1.5 million we can install and run a radio telescope and at the same time join a wider European network of Lofar radio telescopes. This would be the largest international science project that Ireland has joined, said Prof Gallagher.

The Lofar arrays work at radio frequencies below the lowest that will be seen by the Ska. This means there is no duplication of effort and Lofar remains a valuable radio telescopic tool for studying the universe, said Dr van Haarlem.

Ireland could purchase an array for about €850,000, with additional costs for installation. Businessmen Dermot Desmond and Denis O’Brien have joined the project as founding donors, said Prof Gallagher.

Participation would help interest students in the sciences and help form links with universities running Lofar arrays.