kvázar

A quasar, short for quasi-stellar radio source, is an extremely luminous and distant active galactic nucleus. They are among the most energetic and distant objects known in the universe, and are believed to be powered by supermassive black holes at the centers of galaxies. Quasars emit enormous amounts of energy across the electromagnetic spectrum, from radio waves to X-rays, and are often referred to as the "lighthouses" of the universe due to their extreme brightness.

Quasars were first identified in the 1960s through their strong radio emissions. They are typically found at very high redshifts, indicating that they are located billions of light-years away. The energy emitted by quasars is thought to be generated by the accretion of matter onto the supermassive black hole at the galaxy's center, forming an accretion disk that heats up and emits radiation.

The study of quasars has provided valuable insights into the early universe and the formation of galaxies. They are believed to be the precursors of the massive elliptical galaxies that are common in the present-day universe. Quasars also play a crucial role in the reionization of the universe, as their intense radiation ionizes the surrounding intergalactic medium.

Despite their brightness, quasars are not visible to the naked eye due to their immense distance. They are typically observed using large telescopes and specialized instruments. The study of quasars continues to be an active area of research in astrophysics, with scientists using them to probe the nature of black holes, the evolution of galaxies, and the large-scale structure of the universe.