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...
...
Space-like singularities are a feature of non-rotating uncharged black-holes, while time-like singularities are those that occur in charged or rotating black hole exact solutions. Both of them have the following property:
geodesic incompleteness: Some light-paths or particle-paths cannot be extended beyond a certain proper-time or affine-parameter (affine parameter is the null analog of proper time).
It is still an open question whether time-like singularities ever occur in the interior of real charged or rotating black holes, or whether they are artifacts of high symmetry and turn into spacelike singularities when realistic perturbations are added.
Rotating black holes are described by the Kerr metric...The event horizon is rotating as though it were a solid body, so can be characterized by an angular velocity or rotation rate in RPM. For a 10 solar mass black hole rotating at the maximal rate, it is rotating at about 10^4 radians/second or about 10^5 RPM. Larger black holes will rotate at lower RPM rates, but at the maximal rotation rate, a point on the equator of the event horizon is always rotating at 1/2 the speed of light.
A black hole is a region of space where the gravitational pull is so strong that nothing, not even light, can escape from it. It is formed when a massive star collapses under its own weight, creating a singularity at its center.
Black holes are real objects that have been observed and studied by scientists. However, their existence was first predicted by Albert Einstein's theory of general relativity, and their properties are still being studied and understood by scientists.
Black holes are formed when a massive star runs out of nuclear fuel and its core collapses under its own gravity. The collapse creates a singularity, surrounded by an event horizon, which marks the point of no return for anything that enters the black hole.
Magnetic poles and jets are phenomena that are observed in some black holes. The magnetic poles are regions of intense magnetic fields near the event horizon, while jets are powerful streams of particles that are ejected from the black hole's poles at high speeds.
Black holes themselves are invisible, as they do not emit or reflect any light. However, we can observe the effects of black holes on their surroundings, such as the distortion of light and the movement of stars and gas, which help us to confirm their existence and study their properties.