SA telescope to test Einstein

Over 43 000 hours of observing time, adding up to about five years, has been allocated to radio astronomers from around the world for SA's MeerKAT telescope.

The design and construction of the MeerKAT, an operational demonstrator telescope, is a core component of the country's bid to host the Square Kilometre Arrray (SKA) telescope, says the Department of Science and Technology.

The MeerKAT will be one of the largest scientific research facilities in the world and will consolidate Africa as a major global hub for astronomy.

The interest in the SKA's precursor telescope comes five years before the MeerKAT actually becomes operational. Astronomers have applied for the time to do research with the instrument, says the SKA SA Project.

SKA SA says an invitation in October last year to the world's radio astronomers to apply for telescope time to perform large survey projects saw 21 proposals, involving more than 500 astronomers from around the world, with 59 from Africa.

“A Time Allocation Committee made up of local and international experts rated the proposals on the basis of scientific merit, technical and operational feasibility, the extent to which MeerKAT has a unique role for the proposed observations or is an essential component in a larger campaign, and the resources each group was prepared to bring to the project.

“Surveys of radio pulsars and hydrogen gas in the deep universe came out on top in the first round of allocating MeerKAT's observing time.”

The project adds that nearly 8 000 hours of observing time were allocated to a proposal to test Einstein's theory of gravity and investigate the physics of enigmatic neutron stars (radio pulsar timing survey), while 5 000 hours were dedicated jointly to two proposals to survey the distant universe with the MeerKAT.

“These science objectives also happen to be the prime science drivers for the first phase of the SKA telescope itself, confirming MeerKAT's designation as an SKA precursor instrument.”

“In addition, there is a strong case for MeerKAT to participate in the worldwide VLBI (very long baseline interferometry) observations, which use telescopes all around the world, working together, and we will ensure that MeerKAT becomes affiliated to international VLBI networks and will commit time to these observations,” explains Bernie Fanaroff, director of SKA SA.

“We would also like to explore the potential for SETI (search for extraterrestrial intelligence) and for collaboration with NASA on downloading information from their space probes sent to other planets.”

The teams who have submitted the successful proposals will be invited to work with the MeerKAT team throughout the design phase of the telescope, and to become involved in the project's human capacity building programme.

MeerKAT will consist of 64 dishes, each 13.5m in diameter. It will be built in the radio astronomy reserve near Carnarvon, in the Northern Cape, over the next five years. An engineering test bed of seven dishes is already complete.

The final decision regarding the successful host country for mega telescope SKA is expected in 2012, with work due to start in 2013. Operations will start in 2015, provided a significant portion of the array has been commissioned.

The SKA is about 100 times more sensitive than the biggest existing radio telescope. It will consist of approximately 3 000 dish-shaped antennae and other hybrid receiving technologies, with a core of about 2 000 antennae and outlying stations of 30 to 40 antennae each, spiralling out of the core. These stations will be spread over a vast area of up to 3 000km.

The DST says research areas will include observational radio astronomy, radio astronomy instrumentation, digital signal processing, distributed data processing and RF broadband feeds, receivers and cryogenic packages.

SA has spent R258 million on its bid to secure the project. The DST says R23 million was spent on universities, while R155 million had been spent building roads to the site. Another R11.5 million was spent on building accommodation.