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

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

   Homepage   
   


A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Number of Results: 3 Search : bump
2175 A bump
  قوز ِ 2175 آنگستروم   
quz-e 2175 Å

Fr.: bosse à 2175 Å   

The strongest spectral feature in the interstellar → extinction curve occurring in the → ultraviolet and centered at about 2175 Å. The feature is a strong function of the → metallicity of the gas. It appears slightly weaker in the → LMC extinction curve (metallicity about 50% solar), but essentially absent in the → SMC extinction curve (metallicity about 10% solar). Small → interstellar  → graphite  → dust grains or a mixture of graphite and → polycyclic aromatic hydrocarbons (PAHs) grains have been proposed in → dust models to explain the bump. However, at present the → carrier of the 2175 Å feature is basically unidentified.

angstrom; → bump.

big blue bump
  قوز ِ آبی ِ بزرگ   
quz-e âbi-ye bozorg

Fr.: grande bosse bleue   

The broad continuum feature dominating the optical-ultraviolet spectra of AGNs. Most current models attribute the big blue bump to thermal emission from an optically thick accretion disk.

big; → blue; bump, → bump Cepheid.

bump Cepheid
  کِفِیءوسی ِ قوزدار، ~ زوکدار   
Kefeusi-ye quzâr, ~ zokdâr

Fr.: céphéide à bosse   

A subtype of classical → Cepheid variable stars that show a bump on the descending branch of their → light curve.

Bump "a relatively abrupt convexity or bulge on a surface," probably imitative of the sound of a blow; → Cepheid.

Quzdâr, from quz "hump," variant of kuž, → convex, + -dâr "possessing," from dâštan "to have, possess." Zokdâr, from Lori zok "a raised spot, a bulge," cf. Northern Fârs Âbâdé dialect lok " swellimg, knob;" Kefeusi, → Cepheid.