Radio galaxy — Radio galaxies and their relatives, radio loud quasars and blazars, are types of active galaxy that are very luminous at radio wavelengths (up to 1038 W between 10 MHz and 100 GHz). The radio emission is due to the synchrotron process. The… … Wikipedia
Radio astronomy — is a subfield of astronomy that studies celestial objects at radio frequencies. The field originated from the discovery that many astronomical objects emit radiation in the radio wavelengths as well as optical ones. The great advances in radio… … Wikipedia
Radio halo — Radio halos are large scale areas of radio emission found in clusters of galaxies. They do not have an obvious galaxy counterpart, as opposed, for example, to radio galaxies which have AGN counterparts. Their cause is still debated, but they may… … Wikipedia
radio source — Astron. a cosmic object or phenomenon, as a galaxy, pulsar, quasar, or the remnant of a supernova or of a galactic collision, that emits radio waves. [1945 50] * * * ▪ astronomy in astronomy, any of various objects in the universe that emit … Universalium
radio and radar astronomy — Study of celestial bodies by measuring the energy they emit or reflect at radio wavelengths. It began in 1931 with Karl Jansky s discovery of radio waves from an extraterrestrial source. After 1945, huge dish antennas, improved receivers and data … Universalium
GALAXIES — L’observation à l’œil nu d’un ciel constellé d’étoiles montre que celles ci ne sont pas réparties au hasard: elles tendent à se regrouper en une longue écharpe laiteuse qui parcourt la voûte céleste d’un bord à l’autre de l’horizon, et que nos… … Encyclopédie Universelle
Galaxies in fiction — Galaxies other than the Milky Way are popular settings for creators of science fiction, particularly those working with broad scale space opera settings. Among the most common settings are the Andromeda Galaxy, the Magellanic Clouds, and the… … Wikipedia
Radio telescope — A radio telescope is a form of directional radio antenna used in radio astronomy and in tracking and collecting data from satellites and space probes. In their astronomical role they differ from optical telescopes in that they operate in the… … Wikipedia
radio star — noun : a radio source of very small dimensions and relatively strong radiation and sometimes identified with certain small nebulosities and galaxies * * * Astron. Now Rare. a radio source. [1945 50] * * * radio star noun A discrete source of… … Useful english dictionary
Radio-télescope — Radiotélescope Le Radiotélescope Very Large Array en configuration D … Wikipédia en Français
