千年星系表：B波段球和盘光的衰减以及隐含的宇宙尘埃和恒星质量密度
The Millennium Galaxy Catalogue: the B-band attenuation of bulge and disc light and the implied cosmic dust and stellar mass densities
摘要：
基于我们的样本的10095星系与膨胀盘分解，我们得出的经验B波段的内部衰减-倾斜关系星系盘及其相关的中央隆起。我们的结果与独立推导的凝灰岩等尘埃模型，导致对Tau_B^f = 3.8 +/-0.7的螺旋盘的平均不透明度的直接约束（中心面上的B带不透明度）。根据倾斜度的不同，B波段衰减校正值从0.2 - 1.1等变化为光盘和从0.8 - 2.6等的凸起。我们发现，总体而言，在附近宇宙的圆盘中产生的所有B波段光子中，有37%被尘埃吸收，这一数字上升到71%。内部尘埃消光的严重性是这样的，必须将内部尘埃校正在所有大型星系样本的光学研究。这对于光学HST比较进化研究特别相关，因为尘埃特性也将不断演变。我们使用新的结果来修改我们最近的估计的球体和光盘光度函数。根据我们最佳拟合的尘埃模型，我们得出红移为零的宇宙尘埃密度为rho_{dust} ~（5.3 +/- 1.7）x 10^5，h M_{odot} Mpc^-3。这意味着（0.0083 +/- 0.0027），宇宙中百分之h的重子以尘埃的形式存在，（11.9 +/-1.7），h %（Salpeter-'lite' IMF）是恒星的形式（约58%位于星系盘，约10%位于红色椭圆星系，约29%在经典星系凸起中，其余在低光度蓝色球体系统/组件中）。[摘要]
英文摘要：
Based on our sample of 10095 galaxies with bulge-disc decompositions we derive the empirical B-band internal attenuation--inclination relation for galaxy discs and their associated central bulges. Our results agree well with the independently derived dust models of Tuffs et al., leading to a direct constraint on the mean opacity of spiral discs of Tau_B^f = 3.8 +/- 0.7 (central face-on B-band opacity). Depending on inclination, the B-band attenuation correction varies from 0.2 -- 1.1 mag for discs and from 0.8 -- 2.6 mag for bulges. We find that, overall, 37 per cent of all B-band photons produced in discs in the nearby universe are absorbed by dust, a figure that rises to 71 per cent for bulge photons. The severity of internal dust extinction is such that one must incorporate internal dust corrections in all optical studies of large galaxy samples. This is particularly pertinent for optical HST comparative evolutionary studies as the dust properties will also be evolving. We use the new results to revise our recent estimates of the spheroid and disc luminosity functions. From our best fitting dust models we derive a redshift zero cosmic dust density of rho_{dust} ~ (5.3 +/- 1.7) x 10^5, h M_{odot} Mpc^-3. This implies that (0.0083 +/- 0.0027), h per cent of the baryons in the Universe are in the form of dust and (11.9 +/- 1.7), h per cent (Salpeter-`lite' IMF) are in the form of stars (~58 per cent reside in galaxy discs, ~10 per cent in red elliptical galaxies, ~29 per cent in classical galaxy bulges and the remainder in low luminosity blue spheroid systems/components). [Abridged]
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