The Photometric objects Around Cosmic webs (PAC) approach developed in Xu et al. has the advantage of making full use of spectroscopic and deeper photometric surveys. With the merits of PAC, the excess surface density n¯2wp of neighboring galaxies can be measured down to stellar mass 10^10.80 M _⊙ around quasars at redshift 0.8 < z _s < 1.0, with the data from the Sloan Digital Sky Survey IV extended Baryon Oscillation Spectroscopic Survey and the Dark Energy Spectroscopic Instrument Legacy Imaging Surveys. We find that n¯2wp generally increases quite steeply with the decrease of the separation. Using the subhalo abundance-matching method, we can accurately model the n¯2wp both on small and large scales. We show that the steep increase of  n¯2wp toward the quasars requires that a large fraction fsate=0.29−0.06+0.05 of quasars should be satellites in massive halos, and we find that this fraction measurement is insensitive to the assumptions of our modeling. This high satellite fraction indicates that the subhalos have nearly the same probability of hosting quasars as the halos for the same (infall) halo mass and that the large-scale environment has negligible effect on the quasar activity. We show that even with this high satellite fraction, each massive halo on average does not host more than one satellite quasar, due to the sparsity of quasars.

中文翻译：

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宇宙网 (PAC) 周围的光度测量物体。六．类星体的高卫星比例


Xu 等人开发了围绕宇宙网的光度物体 (PAC) 方法。具有充分利用光谱和更深入的光度测量的优势。借助 PAC 的优点，可以测量红移 0.8 < z _s M _⊙ /b2> < 1.0，数据来自斯隆数字巡天 IV 扩展重子振荡光谱巡天和暗能量光谱仪器传统成像巡天。我们发现 n2wp 通常随着间距的减小而急剧增加。使用 subhalo 丰度匹配方法，我们可以在小尺度和大尺度上准确地模拟 n−2wp。我们表明，n−2wp 向类星体的急剧增加要求类星体的很大一部分 fsate=0.29−0.06+0.05 应该是巨大光晕中的卫星，并且我们发现该部分测量对我们建模的假设不敏感。这种高卫星比例表明，对于相同的（落入）晕质量，子晕容纳类星体的概率几乎与晕相同，并且大尺度环境对类星体活动的影响可以忽略不计。我们表明，即使卫星比例如此高，由于类星体的稀疏性，每个巨大的光环平均也不会容纳超过一个卫星类星体。