Artist's rendering of ULAS J1120+0641, a very distant quasar powered by a black hole with a mass two billion times that of the Sun. Credit: ESO/M. Kornmesser

The Chandra X-ray image is of the quasar PKS 1127-145, a highly luminous source of X-rays and visible light about 10 billion light years from Earth. An enormous X-ray jet extends at least a million light years from the quasar. Image is 60 arcsec on a side. RA 11h 30m 7.10s Dec -14° 49' 27" in Crater. Observation date: May 28, 2000. Instrument: ACIS.

Gravitationally lensed quasar HE 1104-1805.

Quasars or quasi-stellar radio sources are the most energetic and distant active galactic nuclei (AGN).

They are quite small in comparison with the energy they put out. Quasars are not much larger than the Solar System. The mechanism of brightness changes probably involves relativistic beaming of jets pointed nearly directly toward us. The highest redshift quasar known (as of June 2011^[update]) has a redshift of 7.085, which means it is about 29 billion light-years from Earth. This estimate is made using the concept of comoving distance.