The radiation we receive from quasars and microquasars comes not from the black holes themselves, but instead originates in the accretion disks which surround them
(see Figure 1). In these accretion disks, angular momentum is gradually removed by some presumably (although not necessarily [48]) dissipative process, causing matter to spiral down into the black hole, converting its gravitational energy into heat, and then, by various processes, radiating this energy.7 The radiation subsequently leaks through the disk, escapes from its surface, and travels along trajectories curved (in space) by the strong gravity of the black hole, eventually reaching our telescopes...However, the theoretical
understanding of disks and jets has largely proceeded separately and the physical link between the two still remains uncertain...
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