Public data from the 2dF quasar survey and 2dF/Sloan Digital Sky Survey LRG and QSO, with their vast reservoirs of spectroscopically located and identified sources, afford us the chance to more accurately study their real-space correlations in the hopes of identifying the physical processes that trigger quasar activity. We have used these two public databases to measure the projected cross-correlation, ω p , between quasars and luminous red galaxies. We find the projected two-point correlation to have a fitted clustering radius of r 0 = 5.3 ± 0.6 and a slope γ = 1.83 ± 0.42 on scales from 0.7 to 27 h –1 Mpc. We attempt to understand this strong correlation by separating the LRG sample into two populations of blue and red galaxies. We measure at the cross-correlation with each population. We find that these quasars have a stronger correlation amplitude with the bluer, more recently star-forming population in our sample than the redder passively evolving population, which has a correlation that is much more noisy and seems to flatten on scales 5 h –1 Mpc. We compare this result to published work on hierarchical models. The stronger correlation of bright quasars with LRGs that have undergone a recent burst of star formation suggests that the physical mechanisms that produce both activities are related and that minor mergers or tidal effects may be important triggers of bright quasar activity and/or that bright quasars are less highly biased than faint quasars.
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机译：来自2dF类星体调查和2dF / Sloan Digital Sky Survey LRG和QSO的公共数据，以及大量位于光谱范围内并已确定来源的光谱库，为我们提供了更准确地研究其真实空间相关性的机会，以期识别物理过程触发类星体活动。我们已经使用这两个公共数据库来测量类星体和发光红色星系之间的投影互相关ωp。我们发现投影的两点相关系数的拟合聚类半径为r 0 = 5.3±0.6，斜率γ= 1.83±0.42，范围从0.7到27 h –1 Mpc。我们试图通过将LRG样本分为蓝色和红色星系两个种群来理解这种强相关性。我们测量与每个人口的相互关系。我们发现，这些类星体与我们的样本中更蓝的，最近形成恒星的种群相比，与更红的被动演化种群相比，具有更强的相关幅度，后者的相关性更嘈杂，并且似乎在<5 h –1的范围内趋于平坦Mpc。我们将此结果与有关分层模型的已发表工作进行了比较。明亮类星体与最近经历恒星爆发的LRG之间的相关性更强，这表明产生这两种活动的物理机制是相关的，较小的合并或潮汐效应可能是明亮类星体活动的重要诱因和/或明亮类星体是不如微弱的类星体那么偏重。
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