Estimating galaxy luminosity functions.
Estimating galaxy luminosity functions.
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DOI：
10.1086/118522
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发表时间：
1997-07
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影响因子：
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通讯作者：
C. Willmer
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文献类型：
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作者：
C. Willmer
本文利用蒙特-卡罗模拟方法对不同的星系光度函数进行了比较。模拟结果表明，Lynden-Bell（1971）的C方法和Sandage，Tammann & Yahil（1979）的STY方法是度量光度函数形状的最佳估计。模拟还表明，STY估计有一个偏见，这样的弱端斜率被低估了陡峭的倾斜的Schechter函数，这种偏见变得相当严重时，样本只包含几百个对象。总体而言，C-是最稳健的估计量，受Schechter参数化和样本大小的弱端斜率的不同值的影响较小。模拟也被用来比较不同的亮度函数归一化的估计。他们表明，大多数方法偏向恢复的平均密度值，这是约20%低于输入值。
In this work a comparison between different galaxy luminosity function estimators by means of Monte-Carlo simulations is presented. The simulations show that the C- method of Lynden-Bell (1971) and the STY method derived by Sandage, Tammann & Yahil (1979) are the best estimators to measure the shape of the luminosity function. The simulations also show that the STY estimator has a bias such that the faint-end slope is underestimated for steeper inclinations of the Schechter Function, and that this bias becomes quite severe when the sample contains only a few hundred objects. Overall, the C- is the most robust estimator, being less affected by different values of the faint end slope of the Schechter parameterization and sample size. The simulations are also used to compare different estimators of the luminosity function normalization. They demonstrate that most methods bias the recovered mean density towards values which are about 20% lower than the input value.