The Quasars they are distant objects that emit large amounts of energy, with radiations similar to those of the stars.
Quasars are hundreds of billions of times brighter than stars. Possibly, they are black holes that emit intense radiation when they capture stars or interstellar gas.
The light we perceive occupies a very narrow range in the electromagnetic spectrum and not all cosmic bodies emit most of their radiation in the form of visible light. With the study of radio waves, radio astronomers began to locate very powerful radio sources that did not always correspond to visible objects.
The word Quasar It is an acronym for quasi stellar radio source.
They were identified in the 1950s. Later they were shown to show a larger redshift than any other known object. The cause was the Dopler effect, which moves the spectrum towards red when objects move away.
The first Quasar studied, 3C 273 is 1.5 billion light years from Earth. Since 1980, thousands of quasars have been identified. Some move away from us at speeds of 90% of that of light.
Quasars have been discovered 12,000 million light years from Earth. This is approximately the age of the Universe. Despite the enormous distances, the energy that arrives in some cases is very large. As an example, the s50014 + 81 is about 60,000 times brighter than the entire Milky Way.
The most spectacular of the quasars is not their remoteness, but that they may be visible. A quasar must be as bright as 1,000 galaxies together so that it can appear as a weak star, if it is several billion light years away. But even more surprising is the fact that this enormous energy comes from a region whose size does not exceed a light year (less than one hundred thousandth of the size of a normal galaxy). The brightness of the quasars oscillates with periods of a few months, therefore, their size must be less than the distance that the light travels in that time.
At first, astronomers did not see any relationship between quasars and galaxies, but the gap between these two types of cosmic objects has gradually filled up when galaxies were discovered whose nuclei have similarities to a quasar. Today, quasars are thought to be the nuclei of very young galaxies, and that the activity in the nucleus of a galaxy decreases over time, although it does not disappear altogether.
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