South Africa's new radio telescope reveals giant outbursts from binary star system

May 16, 2013
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.

(Phys.org) —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 prestigious international 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 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 .

Circinus X-1 is an X-ray binary (or two-star system) where one of the companion stars is a high-density, compact neutron star (a neutron star is an extremely dense and compact remnant of an exploded star and only 20km in diameter.) The two stars orbit each other every 16.5 days in an . When the two stars are at their closest the gravity of the dense neutron star pulls material from the . A powerful jet of material then blasts out from the system.

During the time astronomers, including a team from the University of Southampton, observed Circinus X-1 (13 December 2011 to 16 January 2012) the system flared twice at levels among the highest observed in recent years. KAT-7 was able to catch both of these flares and follow them as they progressed. This is the first time that the system has been observed in such detail during the full flare cycle.

Circinus X-1: The bright region in the middle of this KAT-7 radio image, observed at 1 822 MHz (with 256 MHz bandwidth), shows Circinus X-1 during the flare.

"One way of explaining what is happening is that the compact neutron star gobbles up parts of its companion star and then fires much of this matter back out again," explains Dr Richard Armstrong, an SKA SA Fellow at the University of Cape Town and lead author of the paper. "The dramatic radio flares happen when the matter Circinus X-1 has violently ejected slows down as it smashes into the surrounding medium."

Professor Rob Fender, Head of the Astronomy Research Group at the University of Southampton, says: "Circinus X-1 continues to reveal new aspects of its behaviour, and is arguably the best laboratory for relativistic jet astrophysics in the southern hemisphere. It is furthermore an excellent control to the large population of jets associated with accreting black holes."

Dr Armstrong adds: "These types of observations are crucial for understanding the processes of both accretion of matter onto extremely dense systems, such as and black holes of both about the sun's mass, and also the so-called supermassive variety we now know to be at the centre of most galaxies."

This video is not supported by your browser at this time.
A video by Professor Rob Fender, explaining his research on black holes

KAT-7 is the world's first radio telescope array consisting of composite antenna structures. It is the test array for MeerKAT, a much larger radio array, which is itself in turn a precursor for the dish-based component of the SKA.

The MNRAS study was carried out as part of the development for the ThunderKAT project on MeerKAT, which will find many more of these types of systems in the galaxy and search for new types of radio systems that change rapidly with time.

Professor Fender, who is co-leader of the MeerKAT project, adds: "This project will test the extremes of physics, density, temperature, pressure, velocity, gravitational and magnetic fields, and are beyond anything achievable in any laboratory on Earth. It provides a unique glimpse of the laws of physics operating in extraordinary regimes. Nearly all such events are associated with transient radio emission. By studying radio bursts from these phenomena, we can pinpoint the sources of explosive events, probe relativistic accretion and understand the budget of kinetic feedback by such events in the ambient medium."

Explore further: Smallest known galaxy with a supermassive black hole found

More information: The paper that will appear in the Monthly Notices of the Royal Astronomical Society; "A return to strong radio flaring by Circinus X-1 observed with the Karoo Array Telescope test array KAT-7 (Armstrong et al, 2013)" On Arxiv: arxiv.org/abs/1305.3399

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cantdrive85
1 / 5 (7) May 16, 2013
What exact gravitational mechanism causes the jets? We know it must be gravitation that causes this because there is no other mechanism which can effect anything on such scales. The wonders of gravity are astounding.
radek
1 / 5 (4) May 16, 2013
time when we figure out the jets from neutron stars and black holes can be produced even without accretion is short
Fleetfoot
5 / 5 (1) May 17, 2013
We know it must be gravitation that causes this because there is no other mechanism which can [a]ffect anything on such scales. The wonders of gravity are astounding.


Correct, the jets move at relativistic speeds so have very high kinetic energy and since there is no fusion or other power source in the disc to produce that energy, it must come from the gravitational energy released by the infalling material.
cantdrive85
1 / 5 (8) May 17, 2013
That's according to a failing theory, too bad there is no mechanism which can explain it. These jets are expected with interacting plasma as shown by Anthony Peratt's particle in cell simulations, but to accept such a notion astrophysicists would have to commit career suicide and relegate themselves to a Mickey D's cash register.
Fleetfoot
5 / 5 (4) May 17, 2013
Correct, the jets move at relativistic speeds so have very high kinetic energy and since there is no fusion or other power source in the disc to produce that energy, it must come from the gravitational energy released by the infalling material.


That's according to a failing theory, ...


That's according to the conservation of energy which doesn't fail except in the crank "electric universe" . This is what Peratt says about that:

"The Plasma Universe and Plasma Cosmology have no ties to the anti-science blogsites of the holoscience 'electric universe'."

And this is what the "electric universe" site says about Peratt's site's comment about their site:

"Links

The Plasma Universe

Website of Anthony Peratt, author of Physics of the Plasma Universe. [N.B. The disclaimer is merely Political (in)Correctness.]

http://plasmauniverse.info
"

From:

http://www.holosc...p/links/

Fascinating to see Ralph Sansbury credited at the bottom, I know that crank of old ;-)
cantdrive85
1 / 5 (6) May 17, 2013
The conservation of energy doesn't explain the mechanism of jets, just the NEED for the jets. There is a distinct difference between the EUT and Peratt's Plasma Cosmology. The EUT uses a holistic approach to arrive at a multidisciplinary theory that includes explanations of a wide range of phenomenon, from mythology to cosmology. Peratt's PC is more based upon DIRECT measurements and observations of laboratory plasma then applied to a variety of astrophysical plasmas, theoretical assumptions take a back seat unlike mainstream theories.
The fallacy that the EUT team is anti-science is nonsense, much of the basis of the theory is derived from the same info Peratt uses, however, the EUT is definitely anti-establishment science, that which depends upon untestable theoretical dogmas, i.e. GR, SR, etc... Peratt worked at LANL, so he does have to keep up appearances, the irony is ha has produced a number of papers with members of the EUT team.
Fleetfoot
5 / 5 (5) May 17, 2013
The conservation of energy doesn't explain the mechanism of jets, just the NEED for the jets.


Wrong way round, the existence of the jets which remove energy plus the conservation of energy means there must be an input. That is provided from gravitational potential as the material falls in. Magnetic fields and gravitational frame dragging as well as the pressure caused by intense frictional heating are probably involved in the ejection mechanism but it is a highly turbulent regime so difficult to model.

Peratt worked at LANL, so he does have to keep up appearances, the irony is ha has produced a number of papers with members of the EUT team.


No irony there, many cranks have a serious previous track record. The irony is that he writes that his EU stuff is pseudoscience on his own page that disclaims his own disclaimer on the EU site. It makes him one of the few cranks to publicly admit he is a crank.
cantdrive85
1 / 5 (7) May 17, 2013
Magnetic fields and gravitational frame dragging as well as the pressure caused by intense frictional heating are probably involved in the ejection mechanism but it is a highly turbulent regime so difficult to model.

Blah, blah, probably involved? It's not "difficult" to model, THERE IS NO MODEL according to the standard theory.

As previously stated, Peratt has shown both the morphology and emissions of interacting plasmas has shown a better approximation of galactic phenomenon than any standard model by a long shot.
http://www.plasma...lsen.pdf

Simply placing a plasmoid at the center of a galaxy and all of it's effects plainly and concisely describe ALL of the galactic phenomenon, including jets, bars, spirals, ellipticals, irregulars, as well as the related emissions. Being that galaxies are almost entirely composed of plasma, to believe it will not behave as plasma should seems incredibly arrogant and ignorant.
Fleetfoot
5 / 5 (6) May 17, 2013
Being that galaxies are almost entirely composed of plasma, to believe it will not behave as plasma should seems incredibly arrogant and ignorant.


Being that the vast majority of that mass of plasma is in the form of the thin, x-ray emitting ISM and plays no part in the objects we are discussing, your comments seems either incredibly ignorant or a deliberate misdirection of a style beloved by net cranks.

The fact is that what I said was that the magnetic effects probably DO play a part as they do in some plasmas so try to pay attention instead of just bleating out your usual mantra.
cantdrive85
1 / 5 (6) May 17, 2013
Being that the vast majority of that mass of plasma is in the form of the thin, x-ray emitting ISM and plays no part in the objects we are discussing,

A vast majority of the material in and around the galaxy core is also plasma, the temp and presence of the magnetic fields supports this notion. The jets are plasma, the torus is a plasma torus, all of that "hot gas" is plasma. And all that plasma behaves just as it does in labs and computer simulations on Earth, it is mind boggling that such an obvious notion is ignored. The common thread in regards to all the phenomenon that produces these jets (galaxies, stars, quasars, etc..) is that all those objects are almost entirely plasma. To claim otherwise is "either incredibly ignorant or a deliberate misdirection", the M.O. of pseudo-skeptics. The use of "cranks" and "crackpots" also secures your place of having such title. You mention magnetism, but once again provide no mechanism as to the origin of such fields, nor the jets.
Fleetfoot
5 / 5 (4) May 18, 2013
And all that plasma behaves just as it does in labs and computer simulations on Earth,


Nowhere in any lab on Earth have masses greater then the Solar System been exposed to magnetic fields weaker than the Earths. That's where cranks often go wrong, you think you can analyze such structures qualitatively but once you put the numbers in, reality is very different.

To claim otherwise is "either incredibly ignorant or a deliberate misdirection", the M.O. of pseudo-skeptics.


I paraphrased your own words as was appropriate.

The use of "cranks" and "crackpots" also secures your place of having such title.


Check Peratt's own web site, I gave you the link.

You mention magnetism, but once again provide no mechanism as to the origin of such fields


An accretion disc containing a large mass whose structure is dominated by gravity which is also partly ionized forms a closed loop current (a single-turn transformer in effect) which can create a magnetic field.
cantdrive85
1 / 5 (7) May 19, 2013
Nowhere in any lab on Earth have masses greater then the Solar System been exposed to magnetic fields weaker than the Earths. That's where cranks often go wrong, you think you can analyze such structures qualitatively but once you put the numbers in, reality is very different.


You fail to grasp the scalability of plasma phenomenon, Alfven suggested nearly 30 orders of magnitude, others over 40 orders. The complexity of plasma phenomenon will make any attempt at qualitative analysis somewhat inelegant, that however may be how reality is.

An accretion disc containing a large mass whose structure is dominated by gravity which is also partly ionized forms a closed loop current (a single-turn transformer in effect) which can create a magnetic field.


That sounds an awful lot like a plasma torus, but that would pose a number of issues to your theory. Namely the lack of energy to sustain such a torus w/o an external input.
Fleetfoot
5 / 5 (1) May 20, 2013
An accretion disc containing a large mass whose structure is dominated by gravity which is also partly ionized forms a closed loop current (a single-turn transformer in effect) which can create a magnetic field.


That sounds an awful lot like a plasma torus, but that would pose a number of issues to your theory. Namely the lack of energy to sustain such a torus w/o an external input.


As I said before, plasma effects do play a part in astrophysics, the cranks are the ones that deny that anything other than plasma effects exist.

The energy input, again as I said before, is the gravitational potential energy liberated as the material falls into the potential well.

Think of an electric motor. It relies on magnetic effects for its operation but it still needs a source of power to operate.