A quasar is an extremely bright and distant point-like source visible to radio telescopes. The source is a so-called Active Galactic Nucleus, fueled by a supermassive black hole. Source: https://earthsky.org/astronomy-essentials/definition-what-is-a-quasar…
Tag: AGN
Microlensing measurement of a quasar’s accretion disk
An active galactic nucleus (AGN) is a supermassive black hole residing at the core of a galaxy that is accreting material. The accretion occurs in the vicinity of the hot torus around the nucleus, and it can generate rapidly moving jets of charged particles that emit bright, variable radiation as material ccelertes as it falls inward. Quasars are perhaps the best-known…
Galactic star formation and supermassive black hole masses
Astronomers studying how star formation evolved over cosmic time have discovered that quiescent galaxies (galaxies that are currently not making many new stars) frequently have active galactic nuclei. These AGN accrete material onto hot circumnuclear disks, and the resultant energy is released in bursts of radiation, or as jets of particles moving at close to the speed of light. The suspicion…
Why clouds form near black holes
Clouds in the greater universe are clumpy areas of greater density than their surroundings. Space telescopes have observed these cosmic clouds in the vicinity of supermassive black holes. Source: https://earthsky.org/space/cosmic-clouds-form-near-black-holes…