81 articles
PKS 1510-089
PKS 1510-089 is a flat-spectrum radio quasar, a blazar whose jet points almost at Earth, about 6 billion light-years away and known for dramatic variability.
PKS 2155-304
PKS 2155-304 is a bright high-frequency-peaked BL Lac object at redshift 0.116, detected at TeV energies by H.E.S.S. and famous for its extreme 2006 gamma-ray outburst.
QSO B0420-0127
QSO B0420-0127, also known as PKS 0420-014 and 4FGL J0423.3-0120, is a blazar in Orion at redshift 0.916, a flat-spectrum radio quasar whose superluminal jet has been monitored across the spectrum since 1969.
QSO B1730-130
QSO B1730-130, also known as NRAO 530 or PKS 1730-130, is a blazar at redshift 0.90 and the most distant object imaged by the Event Horizon Telescope.
QSO J0529−4351
QSO J0529−4351 (SMSS J052915.80−435152.0) is a quasar in the constellation Pictor identified in 2024 as the most luminous quasar known, powered by a 17-billion-solar-mass black hole.
QSO J0738+1742
QSO J0738+1742, also known as PKS 0735+178, is a BL Lacertae object, a blazar whose relativistic jet points nearly at Earth; in 2021 it became a candidate source of an IceCube neutrino.
QSO J1512-0906
QSO J1512-0906, better known in the literature as PKS 1510-089, is a flat-spectrum radio quasar at redshift 0.361 with a jet pointed almost directly at Earth.
Quasar clustering
Quasar clustering is the statistical excess of quasar pairs at given separations, measured to show how these active supermassive black holes trace the large-scale structure of the universe.
Quasar luminosity function
The quasar luminosity function is the comoving number density of quasars per unit luminosity, whose evolution with redshift traces the history of accretion onto supermassive black holes.
Quasar quartet
The quasar quartet is the first known system of four quasars in close proximity, discovered in 2015 with the Keck I Telescope in Hawaii and announced in Science.
Radio mode feedback
Radio mode feedback is a mode of active galactic nucleus feedback in which the mechanical energy of radio jets heats gas in massive elliptical galaxies and suppresses cooling and star formation.
Radio-loud quasar
A radio-loud quasar is a quasar whose radio emission, powered by relativistic jets from its central black hole, is strong compared with its optical emission.
Radio-loudness parameter
The radio-loudness parameter R is the ratio of a quasar's radio to optical flux, classically 5 GHz to 4400 Å, dividing quasars into radio-loud and radio-quiet classes.
S5 0014+81
S5 0014+81 is a distant blazar quasar in Cepheus, one of the most luminous known, with a black hole of about 40 billion solar masses.
S5 0716+714
S5 0716+714 is a BL Lacertae object, a blazar whose jet pointed nearly at Earth produces a highly variable, featureless continuum. It was discovered in 1979.
TON 618
TON 618, short for Tonantzintla 618, is a hyperluminous, radio-loud quasar near the border of Canes Venatici and Coma Berenices hosting one of the most massive black holes known.
Triple quasar
A triple quasar is a system of three quasars, each powered by a supermassive black hole, observed close together and physically associated rather than aligned by chance.
UHZ1
UHZ1, also cataloged as UNCOVER-26185, is a galaxy at redshift z = 10.073, lensed by the cluster Abell 2744 and seen about 470 million years after the Big Bang.
UM 287
UM 287 is a distant quasar around which a giant gas nebula was discovered in 2014, seen as a possible direct image of a cosmic web filament.
Z 184-50
Z 184-50, also known as Markarian 421, is a bright nearby blazar in Ursa Major that the Whipple Observatory detected in 1992 as the first TeV blazar.
Z 225-7
Z 225-7 is a catalog designation of Markarian 501, a nearby blazar in Hercules and one of the brightest very-high-energy gamma-ray sources in the sky.