论文标题
中央星系与环境的对齐
Alignment of the central galaxies with the environment
论文作者
论文摘要
在这项工作中，我们将Sloan Digital Sky Server Data Release 16（SDSS DR16）的椭圆度和主要轴位置角度测量与Rodriguez \＆Merchán的小组查找器算法相结合，以确定中央星系与周围的结构和卫星星系的一致性。我们使用两种独立的方法：两点互相关函数的修改版本以及中央星系方向与卫星星系相对位置之间的角度。第一种方法使我们能够研究群集的内部和外部区域，而第二种方法则提供了光环中的信息。我们的结果表明，中央星系在相关函数中呈现AnySotropy，最高$ \ sim 10 H^{ - 1} mpc $，它变成$ \ sim $ 10 \％\％\％\％fortive the最亮的人（$^{0.1} m_ {r} <-21.5 $）。当我们按颜色拆分星系样品时，我们发现红色中央星系是该各向异性的主要贡献者。我们还表明，这种行为不取决于群质量或中央星系椭圆度。最后，我们的结果与以前的发现一致，这表明两点互相关函数是使用所有星系，不仅是其属于的组的互联网对齐的良好示踪剂。此外，此功能使我们能够在较大尺度上探索对齐的行为。
In this work, we combine ellipticity and major axis position angle measurements from the Sloan Digital Sky Server Data Release 16 (SDSS DR16) with the group finder algorithm of Rodriguez \& Merchán to determine the alignment of the central galaxies with the surrounding structures and satellite galaxies lying in their group. We use two independent methods: A modified version of the two-point cross-correlation function and the angle between the central galaxy orientation and the satellite galaxies relative position. The first method allows us to study the inner and outer regions of the cluster, while the second method provides information within the halos. Our results show that central galaxies present anysotropy in the correlation function up to $\sim 10 h^{-1}Mpc$, which becomes $\sim$10\% stronger for the brightest ones ($^{0.1}M_{r}<-21.5$). When we split the galaxy sample by colour, we find that red central galaxies are the main contributors to this anisotropy. We also show that this behaviour does not depend on the group mass or central galaxy ellipticity. Finally, our results are in agreement with previous findings, showing that the two-point cross-correlation function is a good tracer of the galaxy alignments using all galaxies and not only those of the group to which it belongs. In addition, this feature allows us to explore the behaviour of the alignment on larger scales.
