Twenty of the world’s finest radio astronomers are meeting at the University of Malta in Valletta tomorrow to discuss how best to use the world’s current and future radio telescopes.
The scientists will be spending a week in Malta to discuss and design new techniques which will take advantage of the unprecedented scale and resolution that current radio interferometers — instruments which combine the signal of two or more telescopes — will provide.
The conference, titled Radio Imaging in the 21st Century, is being organised by the Institute for Space Sciences and Astronomy (ISSA), within the University of Malta.
“We have the finest brains in astronomy coming to Malta to discuss how to achieve more detailed images of the skies. Several radio telescopes can be combined together to provide resolution good enough to see the atmospheres around exoplanets, as well as image the black hole at the centre of our galaxy,” Prof. Kristian Zarb Adami, director of ISSA, said.
He explained how the Square Kilometre Array, an international project to build a radio telescope tens of times more sensitive and hundreds of times faster at mapping the sky than today’s best facilities, together with the Atacama Large Millimetre Array and the next generation Very Large Array are not your usual kind of telescopes.
“Firstly they observe the universe in different wavelengths to that of optical telescopes and secondly they use a technique called ‘aperture synthesis’ for which English radio astronomer Martin Ryle was awarded the Nobel prize in 1974,” Prof. Zarb Adami added.
Standard telescopes, be they in optical or radio frequencies, are limited in resolution only by the diameter of the lens. However, in interferometry, one edge of the lens can be placed several hundreds of kilometres away from the other edge.
By combining the signals from each side of the lens very carefully, scientists can then synthesise a lens that is hundreds of kilometres in diameter leading to unprecedented clarity of the skies.
“We are working on this process, which is extremely complicated and involves many complex steps to ensure that the reconstructed image is a faithful reproduction of the night sky,” Prof. Zarb Adami said.