The Unity of Active Galaxies (Active Galaxies And Radio Galaxies)

Our Survey of active galaxies and quasars looks rather like a zoo of various cosmic beasts .In each compartment we have a type of galaxy ,frequently named for its discoverer (e.g. lacertid) ,or the technique of discovery (e.g. radio galaxy).What systematic trends emerge when we study these species collectively ?One… Read more“The Unity of Active Galaxies (Active Galaxies And Radio Galaxies)”

Quasi-Stellar Objects ( Active Galaxies And Radio Galaxies)

The remarkable properties of radio galaxies spurred astronomers on in their efforts to find the optical counterparts to radio sources. This stimulus was partially responsible for the discovery, in the early 1960s of quasi-stellar objects or QUASARS. These are extra-galactic radio sources that match up optically with objects that cannot… Read more“Quasi-Stellar Objects ( Active Galaxies And Radio Galaxies)”

Compact Galaxies ( Active Galaxies And Radio Galaxies)

While the Californian astronomer Fritz Zwicky was compiling a catalogue of clusters of galaxies, he found a number of COMPACT GALAXIES of high surface brightness that are barely distinguishable from stars. The red compact galaxies found by Zwicky are prob¬ably normal galaxies with an unusually high surface brightness, while the… Read more“Compact Galaxies ( Active Galaxies And Radio Galaxies)”