Centaurus A


Also found in: Wikipedia.

Centaurus A

An intense radio and X-ray source in the southern constellation Centaurus and a source also of infrared radiation and gamma rays. It is identified with the galaxy NGC 5128 lying at a distance of only 5 megaparsecs from the Solar System, making it the nearest active galaxy. It is an elliptical galaxy, 100 kpc in diameter, cut across by broad belts of gas and dust. A complex elongated radio structure emerges from the center of the gas and dust belts, approximately along their axis of rotation and extending about 400 kpc in each direction. The radio structure consists broadly of two large lobes more or less symmetrically disposed about a central nucleus, from which a jet extends toward one of the lobes. The jet is broken up into a number of knots. This huge radio galaxy, stretching over 9° of the sky, has a flux density at 86 megahertz of 8700 jansky, believed to be synchrotron emission.

Centaurus A is also one of the brightest hard X-ray sources, its spectrum being measured to about 200 kiloelectronvolts. It is also variable on timescales down to a few days, suggesting that most of the X-ray emission arises in the nucleus. An Einstein Observatory image showed not only the bright nucleus but in addition a line of sources, i.e. an X-ray jet, significantly along the axis of the radio lobes. The X-ray emission follows closely the radio jet but extends beyond it into the radio lobe.

Centaurus A

[sen′tȯr·əs ′ā]
(astronomy)
A strong, discrete radio source in the constellation Centaurus, associated with the peculiar galaxy NGC 5128.
References in periodicals archive ?
One explanation for the ring is that it formed in the tumultuous aftermath of the collision in which Centaurus A snared the smaller galaxy.
58-meter New Technology Telescope (NTT), are seeing through the opaque dust lanes of the giant cannibal galaxy Centaurus A, unveiling its "last meal" in unprecedented detail - a smaller spiral galaxy, currently twisted and warped.
A huge jet of high-energy particles shoots out from a supermassive black hole at the core of nearby galaxy Centaurus A.
According to a report by ABC News, the map of Centaurus A, a galaxy in the Centaurus constellation, covers a segment of sky 200 times the area of the full moon.
Powered by a central black hole that sucks in stars and gas, the giant, radio-emitting galaxy Centaurus A got a further jolt several hundred million years ago when it swallowed a disk-shaped galaxy.
The University of Rome detector recorded several rumbles then that coincided more or less with bursts of energetic neutrinos from Centaurus A recorded by a neutrino detector called LSD, located under Mont Blanc.
And when the galaxy is the nearest active galaxy to us, Centaurus A, which also happens to be one of the strongest and longest studied celestial sources of radio waves, the combination provides a rather unique excitement for astronomers.
It is a prominent member of a group of galaxies known as the Centaurus A/M83 Group, which also counts dusty Centaurus A and irregular NGC 5253 as members.
At a distance of around 12 million light years away, Centaurus A is the closest large elliptical galaxy to our own Milky Way.
It was found using NASA technology in the Centaurus A galaxy, which is more than 12 million light years away -
Welsh astronomers studying the galaxy say that Centaurus A appears to have swallowed a neighbouring, smaller galaxy, possibly billions of years ago, and is now belching out its remains from an enormous black hole at its centre.
Summary: TEHRAN (FNA)- An international team of scientists found a 'normal-size' black hole in the 12 million light year-distant galaxy Centaurus A.