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

CSIRO's 64-m Parkes: Detects Enormous Outflow of Energy

Enormous outflows of charged particles from the centre of our Galaxy, stretching more than halfway across the sky and moving at supersonic speeds, have been detected and mapped with CSIRO's 64-m Parkes radio telescope.

Corresponding to the "Fermi Bubbles" found in 2010, the recent observations of the phenomenon were made by a team of astronomers from Australia, the USA, Italy and The Netherlands, with the findings reported in Nature.

"There is an incredible amount of energy in the outflows," said co-author Professor Lister-Staveley-Smith from The University of Western Australia node of the International Centre for Radio Astronomy Research in Perth and Deputy Director of the ARC Centre of Excellence for All-sky Astrophysics (CAASTRO).

"The source of the energy has been somewhat of a mystery, but we know there is a lot there, about a million times as much energy as a supernova explosion (a dying star)."

CSIRO's 64-m Parkes radio telescope

From top to bottom the outflows extend 50,000 light-years [five hundred thousand million million kilometres] out of the Galactic Plane. That's equal to half the diameter of our Galaxy (which is 100,000 light-years-a million million million kilometres-across).

"Our Solar System is located approximately 30,000 light-years from the centre of the Milky Way Galaxy, but we're perfectly safe as the jets are moving in a different direction to us," said Professor Staveley-Smith.

Seen from Earth, but invisible to the human eye, the outflows stretch about two-thirds across the sky from horizon to horizon.

They match previously identified regions of gamma-ray emission detected with NASA's Fermi Space Telescope (then-called "Fermi Bubbles") and the "haze" of microwave emission spotted by the Wilkinson Microwave Anisotropy Probe (WMAP) and Planck Space Telescope.

"Adding observations by the ground-based Parkes radio telescope to those made in the past by space telescopes finally allows us to understand how these enormous outflows are powered," said Professor Staveley-Smith.

Previously it was unclear whether it was quasar-like activity of our Galaxy's central super-massive black hole or star formation that kept injecting energy into the outflows.

The recent findings, reported in Nature today, show that the phenomenon is driven by many generations of stars forming and exploding in the Galactic Centre over the last hundred million years.

Australia Square Kilometre Array Pathfinder (ASKAP): Fastest Radio Telescope on Earth

Australia is now home to the world's fastest radio telescope with the launch Friday of the $152 million Australia Square Kilometre Array Pathfinder (ASKAP), which experts said would allow a more expansive survey of the universe - both known and what remains for scientists to discover s.

The new scientific research site is located in the Shire of Murchison, a sparsely populated area in Western Australia that astronomers have picked out because of the virtual absence of man-made radio signals.

The location is ideal because it is 'radio quiet', or lacks man-made radio signals that would interfere with the antennas picking up astronomical radio signals.

The ASKAP telescope is projected to improve on the previous achievements of similar facilities, giving researchers and scientists more universe space to cover with less time required.

Putting into perspective the speed and efficiency that comes with the ASKAP, scientists said only five minutes will be spent to fully observe Milky Way's neighbouring galaxy, Centaurus A.

Earlier works on the Centaurus A were achieved after two years of careful observations that were aided by thousands of hours of computer analysis and the poring over of hundreds of images, the news agency added.

Now with use of phased array feeds coming from 36 antennas spread over an area of about 50,000 square kilometres, future scientific researchers and observations have become more specific and accurate, scientists said.

Australia will host both the low frequency component of the SKA – which will image the birth of the first stars in the universe - and a world leading survey facility based on CSIRO’s revolutionary Phased Array Feed technology.

Both of these components of the telescope are right at the cutting-edge of radio astronomy technology and data management and will attract some of the best technological brains in the world to Australia.

These well-coordinated radio waves will provide clear snap shots of what man aims to discover out there to better comprehend the universe, National Scientific Research Organisation (NSRO) project director Brian Boyle said in a news briefing held earlier this week.

"Radio waves tell us unique things about the cosmos, about the gas from which stars were formed, and about exotic objects, pulsars and quasars, that really push the boundaries of our knowledge of the physical laws in the universe," Mr Boyle said.

What the new facility has delivered is for astronomers to better understand our own universe and the 'others' on its outer realms, he added.

Over the next few years, the NSRO is gunning to gain more information on the force that led to the creation of Milky Way and its constant expansion, decode the mystery-laden black holes and investigate further on pulsars.

It could be that the new ASKAP telescope would eventually prove that 'man is not alone' after all, Mr Boyle suggested.