What is an accretion disk?

Question

Quizplus · Accepted Answer

An accretion disk is a disk of hot gas that is swirling rapidly around a white dwarf, neutron star, or black hole. The gas in the disk can be accelerated to very high speeds, emitting large amounts of energy in the form of X-rays and other radiation. Accretion disks are thought to be the source of the intense radiation emitted by quasars and other active galactic nuclei. Option A is incorrect because not all flattened disks in space are accretion disks. Option B is incorrect because accretion disks can be found around more than just white dwarfs. Option D is incorrect because it describes a different phenomenon, namely mass transfer between binary stars.

What Is an Accretion Disk