QUASARS Meaning and
Definition
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Quasars, short for quasi-stellar radio sources, are extremely luminous celestial objects that reside in the furthest reaches of the universe. They are considered to be the most energetic and distant members of a class of active galactic nuclei (AGN). These AGNs are compact regions located at the centers of galaxies, believed to contain supermassive black holes surrounded by a swirling disk of gas and dust.
Quasars emit huge amounts of energy across the electromagnetic spectrum, with their brightest emissions occurring in the radio, optical, ultraviolet, and X-ray wavelengths. The energy output of quasars surpasses that of entire galaxies, making them the most radiant objects in the known universe. They can emit thousands of times more energy than the entirety of the Milky Way galaxy.
Initially mistaken for stars due to their point-like appearance in early observations, quasars were later identified as distinct objects due to their extreme redshifts, corresponding to vast distances from Earth. Their redshifts result from their motion away from us, caused by the expansion of the universe.
The powerhouses of quasars are believed to derive from the gravitational energy released as matter falls into the supermassive black holes at their cores. This infalling matter forms an accretion disk, which generates immense heat and emits intense radiation. The study of quasars provides valuable insight into the early universe, the formation and evolution of galaxies, and the nature of supermassive black holes.
Common Misspellings for QUASARS
Etymology of QUASARS
The word "quasar" is an abbreviation of "quasi-stellar radio source". It was originally coined in 1964 by Chinese-born astrophysicist Hong-Yee Chiu, who used the term to describe a new class of extremely bright astronomical objects. These objects were initially identified as radio sources due to their strong radio emissions. However, they had characteristics that were very different from typical stars, leading to the "quasi-stellar" part of the term.
Later, astronomers discovered that these objects were actually extremely distant and energetic celestial bodies, emitting large amounts of light across the electromagnetic spectrum, including radio waves. Since their discovery, the term "quasar" has been widely used to describe these energetic and distant astronomical objects.
The etymology of "quasar" itself is a combination of "quasi-" (meaning "resembling" or "almost") and "stellar" (relating to stars).
Similar spelling word for QUASARS
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