翻訳と辞書 Words near each other ・ Ab Kuleh Sar-e Kuchak ・ Ab Kya Hoga ・ Ab Lami-ye Guzenan ・ AB Landsverk ・ AB language ・ Ab Laran ・ Ab Lashkar ・ Ab Lashkar-e Olya ・ Ab Lashkar-e Sofla ・ Ab Lashkar-e Vosta ・ Ab Laut Aa ・ Ab Lench ・ AB Liner ・ Ab Lishu ・ AB Logic ・ AB magnitude ・ Ab Mahi ・ Ab Mahi, Fars ・ Ab Mahi, Kohgiluyeh and Boyer-Ahmad ・ Ab Maik-e Golzari ・ Ab Mal ・ Ab Mal, Mashhad ・ Ab Mal, Sarakhs ・ Ab Malakh ・ Ab Malek ・ Ab Maru ・ AB Mauri ・ Ab Mazar ・ Ab McDonald ・ Ab Meri Baari Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク AB magnitude ： ウィキペディア英語版 AB magnitude The AB magnitude system is an astronomical magnitude system. Unlike many other magnitude systems, it is based on flux measurements that are calibrated in absolute units, namely spectral flux densities. == Definition == The ''monochromatic'' AB magnitude is defined as the logarithm of a spectral flux density with the usual scaling of astronomical magnitudes and a zero-point of 3631 Jansky, where 1 Jansky = 1 Jy = 10−26 W Hz−1 m−2 = 10−23 erg s−1 Hz−1 cm−2. If the spectral flux density is denoted ''fν'', the monochromatic AB magnitude is: :$m\_\backslash text\; =\; -\backslash frac\; \backslash log\_\; \backslash left(\backslash frac\}\backslash right),$ or :$m\_\backslash text\; =\; -\backslash frac\; \backslash log\_\; \backslash left(\backslash frac\}\backslash right)\; +\; 8.90.$ In cgs units of erg s−1 cm−2 Hz−1, it is: :$m\_\backslash text\; =\; -\backslash frac\; \backslash log\_\; f\_\; -\; 48.600.$ Actual measurements are always made across some continuous range of wavelengths. The ''bandpass'' AB magnitude is defined so that the zero point corresponds to a bandpass-averaged spectral flux density of 3631 Jansky: :$m\_\backslash text\; =\; -\backslash frac\; \backslash log\_\; \backslash left(\backslash frac\; e(\backslash nu)\; d\backslash nu\}\backslash right),$ where ''e(ν)'' is the "equal-energy" filter response function and the ''(hν)''−1 term assumes that the detector is a photon-counting device such as a CCD or photomultiplier. (Filter responses are sometimes expressed as quantum efficiencies, that is, in terms of their response per photon, rather than per unit energy. In those cases the ''(hν)''−1 term has been folded into the definition of e(ν) and should not be included.) The STMAG system is similarly defined, but for constant flux per unit wavelength interval instead. AB stands for "absolute" in the sense that no relative reference object is used (unlike using Vega as a baseline object). 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「AB magnitude」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.