标题： 基于HBQS及其他完整QSO巡天得到的类星体演化 显示英文标题

标题： The QSO evolution derived from the HBQS and other complete QSO surveys

摘要： 一个致力于均匀亮致密类星体巡天（HBQS）的ESO重点研究计划已经完成。在555平方度的范围内，选出了327个类星体（M_B<-23, 0.3<z<2.2），光度范围为15<B<18.75。对于B<16.4，类星体的面密度比PG巡天所测得的高出2.2倍，相当于0.013±0.006 deg^{-2}的面密度。如果加上爱丁堡类星体巡天，观测到的超密度因子为2.5，对应密度为0.016±0.005 deg^{-2}。为了推导类星体光学亮度函数（LF），我们使用了蒙特卡洛模拟，考虑了选择标准、测光误差和类星体光谱斜率分布。对于q_0=0.5和q_0=0.1，LF可以用两个幂律的纯亮度演化（L(z)\propto (1+z)^k）来表示。对于q_0=0.5，k=3.26，比Boyle（1992年）估算的k=3.45慢。LF明亮部分的斜率β=-3.72也需要更平缓。明亮类星体的观测超密度集中在z<0.6。结果表明，在0.3<z<0.6的红移范围内，亮度函数比在更高红移处观测到的更平坦。在这个红移范围内，对于M_B<-25，观测到32个类星体，而我们的最佳拟合PLE模型预测只有19个。为了在整个0.3<z<2.2区间内满意地表示数据，需要亮度相关的亮度演化。 显示英文摘要

摘要： An ESO Key programme dedicated to an Homogeneous Bright QSO Survey (HBQS) has been completed. 327 QSOs (Mb<-23, 0.3<z<2.2) have been selected over 555 deg^2 with 15<B<18.75. For B<16.4 the QSO surface density turns out to be a factor 2.2 higher than what measured by the PG survey, corresponding to a surface density of 0.013+/-.006 deg^{-2}. If the Edinburgh QSO Survey is included, an overdensity of a factor 2.5 is observed, corresponding to a density of 0.016+/-0.005 deg^{-2}. In order to derive the QSO optical luminosity function (LF) we used Monte Carlo simulations that take into account of the selection criteria, photometric errors and QSO spectral slope distribution. The LF can be represented with a Pure Luminosity Evolution (L(z)\propto(1+z)^k) of a two power law both for q_0=0.5 and q_0=0.1. For q_0=0.5 k=3.26, slower than the previous Boyle's (1992) estimations of k=3.45. A flatter slope beta=-3.72 of the bright part of the LF is also required. The observed overdensity of bright QSOs is concentrated at z<0.6. It results that in the range 0.3<z<0.6 the luminosity function is flatter than observed at higher redshifts. In this redshift range, for Mb<-25, 32 QSOs are observed instead of 19 expected from our best-fit PLE model. This feature requires a luminosity dependent luminosity evolution in order to satisfactorily represent the data in the whole 0.3<z<2.2 interval.