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de Vaucouleurs' law (also called the de Vaucouleurs profile) describes how the surface brightness of an elliptical galaxy varies as a function of apparent distance from the center:〔( Recherches sur les Nebuleuses Extragalactiques )〕 : By defining ''Re'' as the radius of the isophote containing half the luminosity (i.e., the radius of the inner disk contributing half the brightness of the galaxy), de Vaucouleurs' law may be written: : or : where ''Ie'' is the surface brightness at ''Re''. This can be confirmed by noting : de Vaucouleurs' law is a special case of Sersic's law, with Sersic index n=4. A number of density laws that approximately reproduce de Vaucouleurs' law after projection onto the plane of the sky include Jaffe's model and Dehnen's model. == References == 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「De Vaucouleurs' law」の詳細全文を読む スポンサード リンク
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