Multiple quasar

When two quasars are so nearly in the same direction as seen from Earth that they appear to be a single quasar but may be separated by the use of telescopes, they are referred to as a 'double quasar'. These are two different quasars, and not the same quasar that is gravitationally lensed. This configuration is similar to the optical double star.

Two quasars, a 'quasar pair', may be closely related in time and space, and be gravitationally bound to one another. These may take the form of two quasars in the same galaxy cluster. This configuration is similar to two prominent stars in a star cluster. A 'binary quasar', may be closely linked gravitationally and form a pair of interacting galaxies. This configuration is similar to that of a binary star system.

See also

• Einstein ring
• List of multiply imaged quasars
• Multiply imaged quasar

References