标题： FRII射电源群体的宇宙学演化 显示英文标题

标题： On the cosmological evolution of the FRII radio source population

摘要： 我们提出一个解析模型，用于研究FRII源群体的宇宙演化。 基于这些物体的固有射电光度-线性尺寸演化的一个早期模型，我们构建了理论源样本。 然后将这些样本在射电功率-线性尺寸平面上的源分布与一个观测到的流量限制样本进行比较。 我们发现，决定FRII物体射电光度的源参数不能彼此独立。 最佳拟合模型预测喷流功率要么与源的寿命相关，要么与源环境密度分布的形状相关。 后一种情况与高红移最明亮射电源比低红移对应物位于更丰富和更扩展环境中的观测趋势一致。 我们还发现了FRII源的一个明显不同于主要群体的类别。 这些源非常古老和/或位于非常稀疏的环境中。 从模型得出的FRII源的光度函数与高光度源的先前结果良好一致。 由于所用比较样本的高流量限制，射电光度函数的明显光度演化未被再现。 发现FRII源的中位线性尺寸的宇宙演化是温和的。 显示英文摘要

摘要： We present an analytical model for the cosmological evolution of the FRII source population. Based on an earlier model for the intrinsic radio luminosity - linear size evolution of these objects, we construct theoretical source samples. The source distributions in the radio power - linear size plane of these samples are then compared with that of an observed flux-limited sample. We find that the source parameters determining the radio luminosity of FRII objects can not be independent of each other. The best-fitting models predict the jet power to be correlated either with the life time of the source or with the shape of the density distribution of the source environment. The latter case is consistent with the observed tendency of the most luminous radio sources at high redshift to be located in richer and more extended environments than their low redshift counterparts. We also find evidence for a class of FRII sources distinctly different from the main population. These sources are extremely old and/or are located in very underdense environments. The luminosity function of FRII sources resulting from the model is in good agreement with previous results for high luminosity sources. The apparent luminosity evolution of the radio luminosity function is not reproduced because of the high flux limit of the used comparison sample. The cosmological evolution of the median linear size of FRII sources is found to be mild.