标题： ROSAT活动星系核光度函数的演化 显示英文标题

标题： Evolution of the ROSAT AGN Luminosity Function

摘要： 我们展示了来自各种ROSAT调查的0.5-2 keV光度函数的结果和参数化，这些调查从ROSAT全天空调查（RASS）的ROSAT明亮调查到Lockman洞的超深调查。一个光度依赖密度演化模型，其中密度演化速率在低光度时下降，提供了对覆盖广泛红移和光度范围的整体XLF的出色参数描述。我们样本中高光度AGN的数量密度演化表现出与光学和射电调查相似的行为，只是我们没有发现z>2.7时数量密度快速下降的证据。这种差异略有显著性，包括更多深空调查结果将有助于更准确地确定该行为。 显示英文摘要

摘要： We present the results and parameterization of the 0.5-2 keV Luminosity Function of AGNs from various ROSAT Surveys, ranging from the ROSAT bright Survey from the ROSAT All-Sky Survey (RASS) to the Ultra-Deep survey on the Lockman hole. A Luminosity-dependent density evolution model, where the density evolution rate drops at low luminosities, gives an excellent parametric description of the overall XLF covering wide ranges of redshift and luminosity. The number density evolution of high-luminosity AGNs in our sample shows a similar behavior to optical and radio surveys, except that we do not find evidence for the rapid decrease of the number density at z>2.7. The discrepancy is marginally significant and including more deep survey results would make better determination of the behavior.