Properties of Black Holes

Properties of black holes

  • Accretion disk – structure (often a circumstellar disk) formed by diffused material in orbital motion around a massive central body, typically a star. Accretion disks of black holes radiate in the X-ray part of the spectrum.
  • Black hole thermodynamics – area of study that seeks to reconcile the laws of thermodynamics with the existence of black hole event horizons.
  • Schwarzschild radius – distance from the center of an object such that, if all the mass of the object were compressed within that sphere, the escape speed from the surface would equal the speed of light.
  • M-sigma relation – empirical correlation between the stellar velocity dispersion \sigma of a galaxy bulge and the mass M of the supermassive black hole at
  • Event horizon – boundary in spacetime beyond which events cannot affect an outside observer.
  • Quasi-periodic oscillation – manner in which the X-ray light from an astronomical object flickers about certain frequencies.
  • Photon sphere – spherical region of space where gravity is strong enough that photons are forced to travel in orbits.
  • Ergosphere – region located outside a rotating black hole.
  • Hawking radiation – black body radiation that is predicted to be emitted by black holes, due to quantum effects near the event horizon.
  • Penrose process – process theorised by Roger Penrose wherein energy can be extracted from a rotating black hole.
  • Bondi accretion – spherical accretion onto an object.
  • Spaghettification – vertical stretching and horizontal compression of objects into long thin shapes in a very strong gravitational field, and is caused by extreme tidal forces.
  • Gravitational lens – distribution of matter between a distant source and an observer, that is capable of bending the light from the source, as it travels towards the observer.

By Trinh Manh Do

%d bloggers like this: