SKA South Africa: MeerKAT telescope foundations complete

The 64th and final foundation for the MeerKAT telescope antenna was poured yesterday (Tuesday, February 11th, 2014) at South Africa's SKA site in the Karoo. 

Close to 5 000 m³ of concrete and more than 570 tons of steel were used to construct the foundations over the last nine months.

MeerKAT is the South African precursor to the Square Kilometre Array (SKA) telescope, to be built in Africa and in Australia.

The SKA Project is an international enterprise to build the largest radio telescope in the world.

"The completion of the foundations and the soon-to-be completed first antenna represents a major milestone on building of the MeerKAT which will become an integral part of the SKA project," says Derek Hanekom, South Africa's Minister of Science and Technology.

"I am very pleased with the progress and the quality of the work that our scientists and engineers are delivering on this challenging assignment and wish them well with the enormous task ahead of meeting the tight schedule in the next two years."

"The foundations were constructed to stringent specifications to ensure that the antennas will be exceptionally stable," said Tracy Cheetham, general manager for infrastructure and site operations at SKA South Africa.

"Even at wind gusts of up to 69 km/h scientists must be able to point the dishes at distant celestial objects in an exact manner, and the antennas must be able to survive wind speeds of up to 144 km/h".

To meet these stability requirements, each foundation consists of eight steel-reinforced concrete piles at depths of between 5 to 10 m, depending on the local soil conditions.

A square slab of concrete (5.2 m x 5.2 m, and 1.25 m thick) rests on top of the piles to add further stability.

The 32 "holding down" bolts are pre-assembled in a circle to form a steel ring cage, or so-called "bird's nest", into which the concrete is cast.

All other MeerKAT infrastructure should be complete by the end of March this year. "We are on the last leg now," said Cheetham, adding that finishing touches are underway in the Karoo Array Processing Building (KAPB) and the power facility.

The KABP, a specialised underground bunker protected from radio frequency interference, will house all the data processing racks and the power and back-up equipment required for MeerKAT.

The primary focus for the next two months will be on verifying that all infrastructure functions according to the required specifications.

Testing involves cold and hot commissioning - Cheetham explains: "During cold commissioning the power is connected without switching on the equipment. During hot commissioning the machines are turned on and tested for a period of time."

Cheetham also said the ducting for the fibre optic cable has been completed, so all that is left now is for the fibre optic contractor, Plessey, to pull through and connect the cable.

MeerKAT facts & figures:

• Each MeerKAT antenna will be 19.5 m high.
• Each reflector (or dish) will be 13.5 x 16 m.
• Each complete antenna (base, pedestal and dish) will weigh 42 tons.
• The configuration (placement) of the anntennas is determined by the science objectives of the telescope:
• 48 foundations are in the core area which is approximately 1 km in diameter;
• The longest distance between any two antennas (the so-called baseline) is 8 km.
• MeerKAT will be the most sensitive radio telescope in the southern hemisphere until the SKA comes online. 
• Once all 64 antennas are operational, the instrument will be sensitive enough to pick up a cell phone signal from Saturn!
• Leading radio astronomy teams around the globe have already signed up to use the instrument as soon as it is ready. 
• The 64 MeerKAT antennas will later also become part of the much larger SKA telescope which is co-hosted between South Africa and Australia.

South Africa's New Radio Telescope SKA Reveals Giant Outbursts from Binary Star System

An artist's impression of the Circinus X-1 system showing the binary (double) star system. 

Two stars orbit each other every 16.5 days in an elliptical orbit. 

The small white sphere is the neutron star - an extremely dense and compact remnant of an exploded star, only about 20 km in diameter. 

The red sphere is an ordinary star - the companion star in this system. 

When the two stars are at their closest, the neutron star pulls material from its companion star. 

An accretion disk (the blue disk) forms around the neutron star, containing the matter that is sucked from the ordinary star. 

Powerful jets of material (the orange rays) then blast out from the neutron star at close to the speed of light, causing powerful flares in radio frequencies. 

Credit: Image courtesy of University of Southampton /SKA South Africa

An international team of astronomers have reported the first scientific results from the Karoo Array Telescope (KAT-7) in South Africa, the pathfinder radio telescope for the $3 billion global Square Kilometre Array (SKA) project.

The results appear in the latest issue of the international astronomical journal Monthly Notices of the Royal Astronomical Society (MNRAS).

Using the seven-dish KAT-7 telescope and the 26 m radio telescope at the Hartebeesthoek Radio Astronomy Observatory (HartRAO), astronomers have observed a neutron star system known as Circinus X-1 as it fires energetic matter from its core into the surrounding system in extensive, compact `jets' that flare brightly, details of which are visible only in radio waves.

Journal Reference: 
R. P. Armstrong, R.P. Fender, G.D. Nicolson, S. Ratcliffe, M. Linares, J.Horrell, L. Richter, M. P. E. Schurch, M. Coriat, P. Woudt, J. Jonas, R. Booth, B. Fanaroff. A return to strong radio flaring by Circinus X-1 observed with the Karoo Array Telescope test array KAT-7. Monthly Notices of the Royal Astronomical Society, 2013

Square Kilometer Array (SKA): Organisation opts for dual site solution

After a tense few months that has had many in Australia and South Africa anxiously awaiting word on whether their particular site will be chosen to host the world’s largest and most sensitive radio telescope, the Square Kilometer Array (SKA) Organisation has finally made its decision.

It’s good news for both bids, with the organization opting for a dual-site solution that will see the SKA telescope shared between Australia and South Africa.

The joint Australia/New Zealand bid and a South African- led bid were left competing after sites in Argentina and Chile were ruled out in 2006.

However, hopes in the Australian camp were dealt a blow earlier this year when it was reported that a confidential report from the SKA Site Advisory Committee favored the South African-led bid.

While an official announcement was expected on April 4, 2012, the SKA Organization instead decided to postpone the announcement while a working group was set up to examine the two sites further, along with the option of a dual site solution.

Noting that both sites had their own advantages and disadvantages, and wishing to be inclusive, the SKA Organisation has now revealed it has agreed on a dual-site solution that will allow the project to take advantage of investments already made by the bidding nations.

The decision will see two of the three SKA receiver components built in Africa, with the third to be constructed in Australia.

The MeerKAT radio telescope, which is currently under construction in the Northern Cape Province of South Africa and will consist of 64 dishes measuring 13.5 m (44 ft) in diameter, will be used to supplement the SKA Phase I dish array, providing the majority of the collection area for the SKA telescope.

The majority of SKA dishes in Phase I will be built in Southern Africa, as will all the dishes and mid frequency aperture arrays for Phase II of the SKA.

Meanwhile, in Australia, SKA dishes will be combined with the 36 dishes of the almost completed Australian SKA Pathfinder (ASKAP) array in Western Australia. All of the low frequency aperture array antennas for Phase I and II will also be built in Australia and New Zealand.

When completed, the SKA will have a total collecting area of approximately one square kilometer (0.38 square miles), with thousands of receptors extending to distances of up to 3,000 km (1,864 miles) from its center.

It will also generate astronomical amounts of data – with each dish transmitting around 160 Gigabits of data per second to a central processor – posing some pretty intensive computing demands to be addressed by the DOME project.

Boasting 50 times the sensitivity and 10,000 times the survey speed of the best current-day telescopes, the SKA will extend the range of the observable universe, while addressing questions in the fields of astrophysics, fundamental physics, cosmology and particle astrophysics.

Construction of Phase I of the SKA is due to start in 2016, with initial observations set for 2019 and full operation scheduled by 2024.

Source: SKA Organisation

Square Kilometre Array (SKA): South Africa wins science panel's backing

A scientific panel has narrowly recommended South Africa over Australia as the best site for the proposed Square Kilometre Array (SKA), an enormous radio telescope.

But the project's member states have yet to make a final decision on where the telescope will go.

A source familiar with the site selection process confirmed that the panel had indeed made a decision, but added that it was a close call. "This is not an enormous preference for one over the other," he says.

The US$2.1 billion SKA radio telescope will be made up of some 3,000 dishes, each 15 metres in diameter.

It will try to answer big questions about the early universe: how the first elements heavier than helium formed, for example, and how the first galaxies coalesced.

The telescope is so sensitive that it could even pick up television signals from distant worlds, something that might aid in the search for extraterrestrial intelligence.

Background
Since 2006, South Africa has competed against a joint bid from Australia and New Zealand to host the project.

The South African site has some compelling advantages: construction costs are lower, and it sits at higher altitude. But the Australian site would be cheaper to insure, and is less likely to be encroached on by future development. The margin in favour of the winner was extremely narrow, the source says.

Final Bid process
Members of SKA's board will meet on 19 March in Manchester, UK, to discuss the scientific panel's recommendations.

The closed meeting will also provide the two bidders with the opportunity to contest any of the panel's recommendations. After the meeting, SKA's board write a commentary to accompany the recommendation, which will inform the final decision.

According to the source, because the two sites are so close in merit, both are still in contention. China, Italy, the United Kingdom and the Netherlands, the SKA's voting board members, could yet decide either way.

It is even possible that the array could be shared between both nations, though this would likely increase the construction costs.

A final site decision could come as soon as 4 April, when a meeting of the board is tentatively scheduled in Amsterdam.

Nature ref: doi:10.1038/nature.2012.10205

ENVISAT Image: Western Cape of South Africa

This Envisat radar image captures the Western Cape Province in South Africa, host of the 2010 World Cup. Cape Town, a World Cup host city and the capital of the province, is seen in white and pink on the northern end of Cape Peninsula, which juts into the Atlantic Ocean. Cape Point and the Cape of Good Hope are located on the peninsula’s southern end.

The majority of the area seen in this image is a botanical wonderland – the Cape floral kingdom. There are only five other floral kingdoms on Earth: the Antarctic, Australasian, Boreal, Neotropic and Palaeotropic. According to the World Wildlife Fund, this unique plant kingdom is more diverse botanically than the richest tropical rainforests, including the Amazon in South America.

The area covers slightly less than 90 000 sq km (roughly the size of Portugal) of the Cape’s total area of 129 370 sq km (roughly the size of Greece). The fynbos biome (bright purple, teal green and baby blue areas) comprises the majority of the kingdom.

Many fynbos – a collection of plants dominated by evergreen, hard-leaved and flowering shrubs – depend on a cycle of fires for their survival, as the heat germinates their seeds and prevents them from degenerating. The fynbos currently faces threats from agriculture, invasive alien plants, urbanisation and climate change.

Robben Island, where Nobel Laureate and former South African President Nelson Mandela was incarcerated for decades, is visible off the coast of Cape Town. The Western Cape is the meeting point of the cold Atlantic Ocean, to the west, and the warm Indian Ocean, to the south.

This image was created by combining three Envisat Advanced Synthetic Aperture Radar acquisitions (3 June 2010, 29 April 2010 and 25 March 2010) taken over the same area. The colours in the image result from changes in the surface that occurred between acquisitions.

H1N1: 'First' Official Swine-flu death in African Continent

South Africa has confirmed its first death from swine flu, believed to be the first officially documented fatality from the virus in sub-Saharan Africa.

Health officials said a 22-year-old student had died on 28 July, and tests had confirmed the cause of death as the onset of Pneumonia following the initial infection by the H1N1 influenza virus.

150 Confirmed Cases

The country has had at least 150 confirmed swine flu cases, the highest officially reported rate in sub-Saharan Africa. This may be due to more stringent testing and reporting methods carried out by the South Africans.

Cases Unreported

The illness has caused hundreds of deaths in North and South America. Dozens more have died in Asia and Europe. Africa was thought to be one of the last continents to be hit by the virus and so far the number of officially reported cases are low.

ECDPC report

South Africa confirmed its first case of the disease on 18 June 2009 and has had 151 cases in total, according to the European Centre for Disease Prevention and Control. The SA health ministry called the student's death "unfortunate and deeply regretted".

Pneumonia

A statement from the ministry said he had been ill for about a week before going to a Western Cape hospital, where he was treated with antibiotics for the onset of pneumonia, often the final stage of the disease. Unfortunately the treatment was unsuccesful and he died two days later.

Mild Cases

The ministry's statement added: "We are encouraged by the fact that the majority of cases in South Africa have so far been mild and we hope that this will remain so, despite this unfortunate death."