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

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 2 Search : torus
obscuring torus
  چنبر ِ تیره‌ساز   
canbar-e tiresâz

Fr.: tore obscurcissant   

A structure of dust and gas postulated to surround the central → black hole in an → active galactic nucleus (AGN). The presence of an obscuring torus allows the unification of the two main types of AGNs containing a → broad-line region (Type I) and a → narrow-line region (Type II), respectively. In this unified model, the two types represent the same sort of object, the appearance of which depends on the viewer's → line of sight. The best evidence for this model comes from spectropolarimetry observations of some type II AGNs in which broad → emission lines are seen in → polarized light, as would happen if the broad-line region truly were hidden, and the light were being reflected off the torus and into the viewer's line of sight.

obscure; → torus.

torus
  چنبر   
cambar (#)

Fr.: tore   

A surface produced by the revolution of a conic section (such as a circle) around a line lying in its plane, but not cutting the conic. The solid enclosed by such a surface.

From L. torus "a round, swelling protuberance."

Cambar "torus," originally "hoop, circle," from Mid.Pers. cambar "hoop; a ring-shaped headdress," cambar vâcik "playing tambourine."