Quasars: The Universe's Brightest Objects
Quasars are small, distant galaxies that have been identified as the most luminous objects in the universe, releasing vast amounts of electromagnetic energy, from radio frequencies to the visible spectrum. In the late 1980s, the nature of Quasars was discovered to be that of small, compact galaxies surrounding a supermassive black hole.
When quasars were first studied, they were noted for having a very high redshift, meaning that such galaxies are old and very far away from earth. It has been observed that these objects are usually close to the size of our solar system, but that they can emit energy many times that of entire galaxies. In the center of each quasar lies a supermassive black hole that exerts a huge amount of force on the relatively small ‘disc’ of matter surrounding it, which is held in place by the constant inward pull, and the fact that objects being pulled towards some central point collide on a regular basis.
The force of gravity accelerating objects towards the black hole causes an immense release of energy when these objects come close together, and is responsible for creating one of the brightest effects in the known universe. In order to maintain this constant emission of energy, black holes in the centers of Quasars need to consume the equivalent of 600 times the mass of earth every minute, which makes them relatively short-lived for a solar body.
Observation of quasars has shown that the emissions of energy vary by year, month or even week, as the amount of energy emitted by the force of gravity depends on where the matter is falling from, and how much matter is interfering with the paths of large objects in the quasar’s disc. This fact was used to show that quasars are small objects, since larger objects can only shift in their emissions on a much slower schedule.
The formation of quasars has not been well-understood, but it is theorized that they can be formed from galaxies with disproportionately large central black holes or the collision of two large galaxies. There is also a high likelihood of a formation of a quasar occurring when the Andromeda galaxy collides with the Milky Way a few billion years from now. This would be considered a rare astronomical event, since all observable quasars are several billion years old. The study of these strange stellar objects continues to prove to be fruitful to the scientific community, as it is believed that the answers to several modern problems in relativity and quantum theory can be solved by examining the behavior of high-energy quasars.