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How are quasars connected to supermassive black holes?
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Galaxy
The Whirlpool Galaxy (left), also known as M51, an Sc galaxy accompanied by a small irregular companion galaxy, NGC 5195 (right).
Quasars are powered by the gravitational accretion of matter onto supermassive black holes located at the centers of large galaxies.12
The connection between these two phenomena is defined by the following process:
- Accretion Mechanism: As gas and matter fall toward a supermassive black hole, they possess sufficient angular momentum to form a rapidly rotating accretion disk.13
- Energy Production: Within this disk, turbulence and viscosity cause the matter to lose energy and spiral inward, heating the gas to incandescence. This process releases immense amounts of energy, allowing a compact region—often no larger than the solar system—to outshine an entire galaxy.314
- Episodic Activity: Quasar activity is considered an episodic phase in the life cycle of a galaxy, often triggered by events such as galactic mergers that provide a fresh supply of fuel to the central black hole.54
- Evolutionary Impact: During this active phase, the intense radiation and jets produced by the black hole can heat or expel the host galaxy's interstellar medium, eventually shutting down both star formation and the quasar's own fuel supply.5