Quasars Help (page 3)

By — McGraw-Hill Professional
Updated on Sep 18, 2011

Anatomy Of Quasars

The internal anatomy of quasars is still largely a mystery. It seems that the quasars are very distant and also very powerful sources of energy. Suppose that we accept this hypothesis without further question. If we are willing to do this, then certain things can be deduced about quasars.

The quasars are much farther away than all the nearby galaxies. (In this sense, nearby means within several hundred million light-years.) Quasars are not only distant, but they are extremely distant. Without exception, they show large red shifts in their spectral lines. In the Cosmos, distance is time; when we look at something 2 billion light-years away, we are looking 2 billion years into the past. Whenever we look at a quasar, we gaze into a past so remote that the Earth itself was much different than we know it today. Suppose that the quasars are—or were—a common phenomenon of the Universe in its younger age? This is a tempting proposition.

The present estimate of the age of our Universe is on the order of 12 billion to 15 billion years. Some of the quasars, at distances approaching 10 billion light-years, are thus images of the Universe at less than half its present age. Many stars have lifespans of much less than 10 billion years. Suppose that the quasars are young galaxies?

Observations of quasars and radio galaxies often reveal striking similarities, so some astronomers believe that quasars and radio galaxies are in fact the same sort of object. The nuclei of radio galaxies have diameters much less than that of a typical galaxy, but they put out vast amounts of energy. They share this characteristic with quasars. When we look at the most distant known radio galaxies with visual apparatus, we see only the brilliant nuclei; the peripheral glow is washed out by the light from the core.

When large amounts of matter are concentrated into a small volume of space, the gravitation can have profound effects. Do dense congregations of stars, such as exist in the centers of spiral galaxies, gravitationally seal themselves off from the rest of the Universe? That is, do they become black holes? The stars near the periphery of the congregation will, in this case, orbit the central region at great speeds before being pulled forever into the mass. Their high velocity and the accompanying magnetic fields would produce large amounts of EM energy at visible and radio wavelengths. Are quasars active black holes, like cosmic tornadoes?

Yet another theory concerning the origin and anatomy of the quasars suggests that they are points in space through which new matter is entering from some other space-time continuum. Such objects, in the vernacular of the cosmologist, are called white holes . As matter bursts into our space-time continuum, having been pulled from another Universe by overwhelming gravitational forces, the flash of radiant energy would outshine any typical galaxy. Direct evidence to support this theory is lacking, but it is one of the most fascinating in all cosmology. It implies that there exist other universes with space-time singularities connecting them with ours.

Practice problems of this concept can be found at: Galaxies and Quasars Practice Problems

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