论文标题
SDSS DR7和Elucid模拟的星系组（HALO）对齐
Galaxy-group (halo) alignments from SDSS DR7 and the ELUCID simulation
论文作者
论文摘要
基于来自Sloan数字天空调查（SDSS）的星系（SDSS）和Subhalos在相应的重建区域中的旧模拟模拟中，我们研究了中心星系相对于组目录中的宿主组的对齐，以及相对于Elucid模拟中相应的Subhalos的对齐。观察中的星系使用新型的邻里丰度匹配方法将观测中的星系与厄卢克斯模拟中的暗物质苏巴洛斯匹配。在观察中，发现星系的主要轴优先与宿主组的主要轴线排列。星系组比对的颜色依赖性是，红色中心沿其宿主群的主要轴比蓝色中心具有更强的比对。将星系组合在厄一切模拟中的观测和Subhalos中，我们还发现，中央星系具有其主要轴，可以使其与寿司模拟中相应Subhalos的主要轴对齐。我们发现，在更大的光环中的星系中，星系组和星系 - subhalo对准信号更强。我们发现，在模拟中，主Subhalos与SDSS匹配的SUBHALO系统之间的比对比观测中的星系组比对略强。
Based on galaxies from the Sloan Digital Sky Survey (SDSS) and subhalos in the corresponding reconstructed region from the constrained simulation of ELUCID, we study the alignment of central galaxies relative to their host groups in the group catalog, as well as the alignment relative to the corresponding subhalos in the ELUCID simulation. Galaxies in observation are matched to dark matter subhalos in the ELUCID simulation using a novel neighborhood abundance matching method. In observation, the major axes of galaxies are found to be preferentially aligned to the major axes of their host groups. There is a color dependence of galaxy-group alignment that red centrals have a stronger alignment along the major axes of their host groups than blue centrals. Combining galaxies in observation and subhalos in the ELUCID simulation, we also find that central galaxies have their major axes to be aligned to the major axes of their corresponding subhalos in the ELUCID simulation. We find that the galaxy-group and galaxy-subhalo alignment signals are stronger for galaxies in more massive halos. We find that the alignments between main subhalos and the SDSS matched subhalo systems in simulation are slightly stronger than the galaxy-group alignments in observation.
