The quasar luminosity function (QLF) shows the active galactic nucleus (AGN) demography as a result of the combination of the growth and the evolution of black holes, galaxies, and dark matter halos along the cosmic time. The recent wide and deep surveys have improved the census of high-redshift quasars, making it possible to construct reliable ultraviolet (UV) QLFs at 2 ≲ z ≲ 6 down to M ₁₄₅₀ = − 23 mag. By parameterizing these up-to-date observed UV QLFs that are the most extensive in both luminosity and survey area coverage at a given redshift, we show that the UV QLF has a universal shape and its evolution can be approximated by a pure density evolution (PDE). In order to explain the observed QLF, we construct a model QLF employing the halo mass function, a number of empirical scaling relations, and the Eddington ratio distribution. We also include the outshining of AGN over its host galaxy, which made it possible to reproduce a moderately flat shape of the faint end of the observed QLF (slope of ∼ − 1.1). This model successfully explains the observed PDE behavior of UV QLF at z > 2, meaning that the QLF evolution at high redshift can be understood under the framework of halo mass function evolution. The importance of the outshining effect in our model also implies that there could be a hidden population of faint AGNs (M ₁₄₅₀ ≳ − 24 mag), which are buried under their host galaxy light.

类星体光度函数 (QLF) 显示了活动星系核 (AGN) 人口统计，这是黑洞、星系和暗物质晕沿宇宙时间的增长和演化相结合的结果。最近广泛而深入的调查改进了对高红移类星体的普查，使得在 2 ≲ z ≲ 6 低至M ₁₄₅₀处构建可靠的紫外 (UV) QLF 成为可能= - 23 mag。通过参数化这些最新观测到的在给定红移的光度和勘测区域覆盖范围内最广泛的 UV QLF，我们表明 UV QLF 具有通用形状，其演化可以通过纯密度演化来近似。 PDE）。为了解释观察到的 QLF，我们构建了一个 QLF 模型，该模型采用了光晕质量函数、一些经验缩放关系和爱丁顿比率分布。我们还包括 AGN 在其宿主星系上的亮度，这使得可以再现观察到的 QLF 暗端的适度平坦形状（斜率为 ~ - 1.1）。该模型成功地解释了在z处观察到的 UV QLF 的 PDE 行为> 2，意味着可以在晕质量函数演化的框架下理解高红移的QLF演化。在我们的模型中，超越效应的重要性还意味着可能隐藏着一群暗淡的 AGN（M ₁₄₅₀ ≳ − 24 mag），它们被掩埋在它们的宿主星系光下。