Quiescent describes a state in which an astronomical object, such as a galaxy or black hole, is inactive or exhibits minimal activity. It contrasts with active states where significant energy emission and other dynamic phenomena occur.
congrats on reading the definition of quiescent. now let's actually learn it.
Quiescent galaxies are those that show very low levels of star formation compared to active galaxies.
A quiescent supermassive black hole emits little to no radiation, making it difficult to detect with conventional astronomy tools.
Quiescence in a galaxy can follow periods of intense activity, such as those seen in quasars or starburst events.
Understanding quiescent phases helps astronomers learn about the life cycles of galaxies and supermassive black holes.
Observations of quiescent objects often rely on indirect methods, such as studying the motions of nearby stars or gas clouds.
Review Questions
What distinguishes a quiescent supermassive black hole from an active one?
How does the state of being quiescent affect the detectability of a galaxy?
Why is studying quiescent galaxies important for understanding cosmic evolution?
Related terms
Active Galactic Nucleus (AGN): A region at the center of some galaxies that is extremely luminous due to energetic processes involving a supermassive black hole.
Quasar: An extremely bright and distant active galactic nucleus powered by a supermassive black hole.
Starburst Galaxy: A galaxy undergoing an exceptionally high rate of star formation compared to average galaxies.