The large-scale effect of environment on galactic conformity
The large-scale effect of environment on galactic conformity
复制标题
环境对银河整合的大规模影响
DOI：
10.1093/mnras/sty832
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发表时间：
2018
影响因子：
4.8
通讯作者：
盘军
中科院分区：
文献类型：
--
作者：
孙双鹏;郭琦;王岚;Cedric Lacey;王杰;高亮;盘军
我们使用来自斯隆数字巡天数据版本7的一个体积有限的星系样本来探索银河系整合对大尺度环境的依赖，这是在∼4 MPC尺度上测量的。我们发现，邻近星系的恒星形成活动更强烈地依赖于环境，而不是其主星系的活动。在密度过低的区域，大多数邻近星系往往是活跃的，而在密度过高的区域，无论其主要星系的活动如何，邻近星系大多是被动的。在给定的恒星质量下，被动主星系位于比主动型主星系密度更高的区域，这导致了明显强烈的整合信号。邻近星系的活动对环境的依赖性可以用卫星星系所占比例的相应依赖性来解释。对于半解析模型中的星系也发现了类似的结果，这表明不需要新的物理学来解释观察到的大规模整合。
We use a volume-limited galaxy sample from the Sloan Digital Sky Survey Data Release 7 to explore the dependence of galactic conformity on the large-scale environment, measured on ∼4 Mpc scales. We find that the star formation activity of neighbour galaxies depends more strongly on the environment than on the activity of their primary galaxies. In underdense regions most neighbour galaxies tend to be active, while in overdense regions neighbour galaxies are mostly passive, regardless of the activity of their primary galaxies. At a given stellar mass, passive primary galaxies reside in higher density regions than active primary galaxies, leading to the apparently strong conformity signal. The dependence of the activity of neighbour galaxies on environment can be explained by the corresponding dependence of the fraction of satellite galaxies. Similar results are found for galaxies in a semi-analytical model, suggesting that no new physics is required to explain the observed large-scale conformity.