Staff Writer
THE Square Kilometre Array (SKA) telescope in the Northern Cape will enable scientists to make enormous 3D maps of the universe which will survey it across cosmic time.
Scientists say it will be like making a movie of the development of the universe from its infancy to where it is today.
The SKA Organisation, which includes scientists from 11 countries, is bringing up to date the science case for the telescope, and South African scientists are playing a leading role in many of the working groups.
The SKA Cosmology Working Group is chaired by Roy Maartens, of the University of the Western Cape.
Maartens and Mario Santos, also from UWC, have played a leading role with other South African scientists in setting out the SKA science.
Researchers said yesterday they had devised a way of using the SKA, the world’s largest telescope, in new ways that would help shape the future of cosmology.
Santos said usually a map of the universe was made by using galaxies as tiny beacons of the large-scale structure of the universe.
“This is quite demanding as it requires the mapping of large numbers of galaxies across the sky. The survey we are proposing will measure the emitted radiation from all the hydrogen atoms spread across the universe without actually detecting galaxies.
“This will make it easier to survey all of the sky across cosmic times, allowing the phase one of the SKA to become an extremely competitive cosmology machine,” Santos said.
He explained that by making use of 3D maps of the universe, scientists would be able to test the limits of the general relativity theory, and may find some signature of new physics that could shed lights on the true nature of dark energy.
“Moreover, we can look for imprints of what happened at the very beginning of the universe.”
Santos said an experiment of this nature, using intensity mapping, had never been done before. The largest 3D maps of the large-scale structure of the universe had been done using optical telescopes. The current project would be 50 times larger.
Other experiments, such as the Euclids satellite, would be able to probe a large part of the universe, but none would match the SKA in terms of size and depth.
“It will be like making a movie of the universe from a young age when it was only about 2 billion years old until today, when it is about 14 billion years old. The movie will be low-resolution, but enough to test the fundamentals of cosmology,” said Maartens.
He described the SKA telescope as a physics lab, allowing many different experiments to be pursued at the same time. They will allow scientists to push the limits of current knowledge about the universe.