论文标题
微弱的类星体生活在与z〜4处的莱曼破裂星系相同的数量密度环境中
Faint Quasars Live in the Same Number Density Environments as Lyman Break Galaxies at z ~ 4
论文作者
论文摘要
表征High-Z类星体环境是了解类星体和周围星系的共同发展的关键。为了限制他们的全球情况，我们根据超级Suprime-CAM Subaru战略计划调查，统计地检查了Z〜4处570个微弱的类星体候选物的G-Dropout Galaxy过度分布。我们比较了类星体周围的G-Dropout星系的过度密度意义与G-Dropout星系周围的星系，并且它们的分布之间没有显着差异。 A total of 4 (22) out of the 570 faint quasars, 0.7_{-0.4}^{+0.4} (3.9_{-0.8}^{+0.8}) %, are found to be associated with the > 4 sigma overdense regions within an angular separation of 1.8 (3.0) arcmin, which is the typical size of protoclusters at this epoch.这类似于与> 4 Sigma过度密度区域相关的G-Dropout星系的比例。该结果与我们先前的工作一致，即1.3 _ { - 0.9}^{+0.9}％和2.0 _ { - 1.1}^{+1.1}％在Sloan Digital Sky调查中在1.8和3.0 Arcmin内的> 4 sigma undense sigma uneventions中检测到的发光数量。因此，我们建议类星体周围的星系数密度与它们的亮度无关，并且大多数类星体在Z〜4处的最富有的原始集群区域中并不优先出现。缺乏类星体和原始群体之间的明显正相关，而原始的原始速率则可能是：i）i）在含量较低的区域中，或者在protical较低的区域中，或者在proties secient中相对较低，或者是protieser的较低的较低的区域，或者是较低的较低的较低的景点，或者是较低的较低的较高的区域。 iii）在原始区域中存在一些尘埃刺激的类星体。
Characterizing high-z quasar environments is key to understanding the co-evolution of quasars and the surrounding galaxies. To restrict their global picture, we statistically examine the g-dropout galaxy overdensity distribution around 570 faint quasar candidates at z ~ 4, based on the Hyper Suprime-Cam Subaru Strategic Program survey. We compare the overdensity significances of g-dropout galaxies around the quasars with those around g-dropout galaxies, and find no significant difference between their distributions. A total of 4 (22) out of the 570 faint quasars, 0.7_{-0.4}^{+0.4} (3.9_{-0.8}^{+0.8}) %, are found to be associated with the > 4 sigma overdense regions within an angular separation of 1.8 (3.0) arcmin, which is the typical size of protoclusters at this epoch. This is similar to the fraction of g-dropout galaxies associated with the > 4 sigma overdense regions. This result is consistent with our previous work that 1.3_{-0.9}^{+0.9} % and 2.0_{-1.1}^{+1.1} % of luminous quasars detected in the Sloan Digital Sky Survey exist in the > 4 sigma overdense regions within 1.8 and 3.0 arcmin separations, respectively. Therefore, we suggest that the galaxy number densities around quasars are independent of their luminosity, and most quasars do not preferentially appear in the richest protocluster regions at z ~ 4. The lack of an apparent positive correlation between the quasars and the protoclusters implies that: i) the gas-rich major merger rate is relatively low in the protocluster regions, ii) most high-z quasars may appear through secular processes, or iii) some dust-obscured quasars exist in the protocluster regions.
