Black Hole Accretion Disc Energies

A black hole is a massive object whose gravitational field is so intense that nothing - not even light (electromagnetic radiation) — can escape from within its so-called event horizon. Accretion disks of hot material encircle many black holes, and this material emits X-rays and other forms of energy. Gas closer to the black hole is hotter and emits more energetic radiation. Gas at the innermost stable orbit tells astronomers whether the black hole is spinning because a rotating black hole can host material in stable orbits much closer to its event horizon. Oppositely directed jets of gas often form in the innermost zone of black hole accretion disks.