An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

A member of a small subset of quasars consisting of bright radio galaxies whose flux of visible light output can vary by as much as 50% in a single day.

→ optically; → violent; → variable; → quasar.

Intense in force, effect; severe; extreme.
See also: → optically violent variable (OVV) quasar, → violent galaxy, → violent interstellar environment, → violent relaxation, → violent star formation.

M.E., from O.fr. violent, from L. violentus "vehement, forcible."

Surâ, from Av. sūra- "strong, powerful, mighty;" cf. Skt. śūra- "strong, powerful, valiant."

A type of galaxy that releases a tremendous amount of energy, on the average 10⁵⁸ ergs, compared with a supernova release of 10⁴⁹ ergs. Violent galaxies include quasars and exploding galaxies. About 1 percent of the galaxies are classified as violent. The nearest violent galaxy is Cen A.

→ violent; → galaxy.

A description of the interstellar medium justified by the presence of supersonic shock waves, massive star winds, turbulence, supernova explosions, etc.

→ violent; → interstellar; → environment.

A process in which a dynamical system made up of many objects (star cluster, galaxy cluster) rapidly relaxes from a chaotic initial state to a quasi-equilibrium.

→ violent; → relaxation.

The concept of star formation pertaining to a variety of systems (OB associations, giant H II regions, H II galaxies, massive star clusters, etc.) that are believed to have formed large numbers of stars in a very short time.

→ violent; → star formation.