The Distribution of Satellite Galaxies in the IllustrisTNG100 Simulation
The Distribution of Satellite Galaxies in the IllustrisTNG100 Simulation
复制标题
DOI：
10.3847/1538-4357/ac752d
复制
发表时间：
2022-05
期刊：
影响因子：
--
通讯作者：
B. McDonough;T. Brainerd
中科院分区：
文献类型：
--
作者：
B. McDonough;T. Brainerd
我们在IllustrisTNG100模拟中研究了孤立宿主星系卫星的空间分布。与之前对Illustris-1模拟的类似分析一致，卫星通常是较差的平均宿主质量密度示踪器。与Illustris-1卫星不同，这里完整卫星样本的空间分布与NFW剖面很好地拟合；然而，浓度比平均宿主质量密度低约2倍。卫星中最亮的50%和最暗的50%的空间分布也很好地符合NFW剖面，但浓度相差约2倍。当样本按宿主颜色和亮度细分时，蓝色卫星的数量密度分布通常低于平均宿主质量密度分布，而红色卫星的数量密度分布通常高于平均宿主质量密度分布。这些相反的、系统的偏移结合在一起，在最亮的蓝色宿主的平均质量密度剖面和它们的卫星相应的数量密度剖面之间产生了比较好的一致性。最后，我们根据它们加入宿主时的红移对卫星进行细分。由此，我们发现无论是最老的三分之一卫星还是最年轻的三分之一卫星都不能忠实地追踪平均宿主质量密度。
We investigate the spatial distribution of the satellites of isolated host galaxies in the IllustrisTNG100 simulation. In agreement with a previous, similar analysis of the Illustris-1 simulation, the satellites are typically poor tracers of the mean host mass density. Unlike the Illustris-1 satellites, here the spatial distribution of the complete satellite sample is well fitted by an NFW profile; however, the concentration is a factor of ∼2 lower than that of the mean host mass density. The spatial distributions of the brightest 50% and faintest 50% of the satellites are also well fitted by NFW profiles, but the concentrations differ by a factor of ∼2. When the sample is subdivided by host color and luminosity, the number density profiles for blue satellites generally fall below the mean host mass density profiles, while the number density profiles for red satellites generally rise above the mean host mass density profiles. These opposite, systematic offsets combine to yield a moderately good agreement between the mean mass density profile of the brightest blue hosts and the corresponding number density profile of their satellites. Lastly, we subdivide the satellites according to the redshifts at which they joined their hosts. From this, we find that neither the oldest one-third of the satellites nor the youngest one-third of the satellites faithfully trace the mean host mass density.