Jets from Black-Hole Binaries and Galactic Nuclei.

Relativistic outflows are a common phenomenon in accreting black holes. Despite the enormous differences in scale, stellar-mass black holes in binaries and supermassive black holes in galactic nuclei produce jets with analogous properties. In both two types of relativistic outflows are observed: 1) steady compact jets with flat-spectrum, and 2) sporadic extended jets with steep-spectrum and apparent superluminal motions. Besides, the most common class of gamma-ray bursts are afterglows from ultra-relativistic jets associated to the formation of black holes at cosmological distances. [ABSTRACT FROM AUTHOR]