Galaxies in Turmoil: The Sources of Power in The Depths of Space

Galaxies in Turmoil: The Sources of Power in the Depths of Space

By Mr Ghaz, March 4, 2011

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Galaxies in Turmoil: The Sources of Power in the Depths of Space

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In recent years astronomers have realized that some of the billions of galaxies scattered through space-a few in every hundred-are in violent turmoil at their cores. Huge quantities of light, heat radiation, radio waves, and X-rays pour out from the centers of these active galaxies.

One of the scenes of violent activity is a source of radio waves: Cygnus A. When the galaxy was first pinpointed in 1953, astronomers believed that its huge energy output was the result of the collision of two galaxies. But recent research indicates that Cygnus A, three times as wide as our own galaxy, with a thousand times more mass, is flanked by huge “lobes” of invisible matter that emit radio waves. These radio waves are a million times stronger than those emitted by our own galaxy.

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What creates such activity in Cygnus A? Astronomers believe that two jets of electrically charged particles-two gigantic electric currents-are being fired out of the core of the galaxy in opposite directions. When the jets collide with intergalactic gas, they heat it up and create magnetic fields. The magnetic fields, in turn, force the particles into spiraling paths that emit radiation.

Power Packs of the Universe

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What is responsible for the jets is a quasar. Through an optical telescope, quasars look like ordinary stars. But they pour out far more energy-actually more than many a galaxy, from an area no larger than the solar system. Quasar 3C 273, for example, is 20 times brighter than the galaxy in which it is embedded.

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Some astronomers have suggested that a quasar is a young galaxy with a black hole at its center. Black holes are areas of intense gravitational strength in space that draw all surrounding matter into them; a black hole with the mass of the sun would be so dense it would be no larger than a baseball. As the massive gravitational pull draws matter into the black hole, intense amounts of energy are emitted. The jets consist of incandescent matter blown outward from the quasar and focused into beams by its magnetic field.

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Another enormously powerful quasar lies in M87, a galaxy at the heart of the thickly populated Virgo cluster of galaxies. Astronomers believe that the stars of M87 are under the gravitational control of a black hole with the mass of 5 billion suns.

But there is another opinion. H.C. Arp of the Hale Observatories in Los Angeles claims to have detected “bridges of matter” that connect quasars with galaxies that are relatively close to earth.

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If his theory is correct, quasars are nowhere near as distant as originally believed, and therefore are not us powerful. According to Arp and a growing number of supporters, quasars are large amounts of matter ejected from explosions at the heart of young, active galaxies.

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Whatever quasars are, we could be seeing what happens when a galaxy is born. If, on the other hand, quasars are distant-the farthest may lie more than 15 billion light-years away-what we are observing today happened 15 billion years ago, which could offer important clues about the origin of the universe.

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