Alignment of the central galaxies with the environment
Alignment of the central galaxies with the environment
复制标题
中央星系与环境的对齐
DOI：
10.1093/mnras/stac1428
复制
发表时间：
2022
影响因子：
4.8
通讯作者：
M. Artale
中科院分区：
文献类型：
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作者：
F. Rodriguez;M. Merchán;M. Artale
在这项工作中，我们将来自斯隆数字天空服务器数据发布16(SDSS DR16)的椭圆度和长轴位置角测量与Rodriguez&Merchán的群探测器算法相结合，以确定中心星系与周围结构和位于其群中的卫星星系的排列。我们使用了两种独立的方法：两点互相关函数的修正版本和中心星系方向与卫星星系相对位置之间的夹角。第一种方法使我们能够研究星系团的内部和外部区域，而第二种方法提供了光晕内的信息。我们的结果表明，在∼10 h−1∼之前，中心星系在相关函数上呈现各向异性，对于最亮的星系(0.1MR<；−21.5)，它变得比Mpc强10%。当我们按颜色分割星系样本时，我们发现红色中心星系是造成这种各向异性的主要因素。我们还表明，这种行为不依赖于星系群质量或中心星系的椭圆度。最后，我们的结果与以前的发现一致，表明两点互相关函数是使用所有星系而不仅仅是它所属的星系组的星系排列的很好的示踪剂。此外，此功能允许我们在更大的比例上探索对齐的行为。
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 haloes. Our results show that central galaxies present anysotropy in the correlation function up to ∼10 h−1 Mpc, which becomes ∼10 per cent stronger for the brightest ones (0.1Mr < −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.