论文标题
TNG100模拟中卫星星系的分布
The Distribution of Satellite Galaxies in the TNG100 Simulation
论文作者
论文摘要
我们研究了TNG100模拟中分离的宿主星系的卫星的空间分布。与先前对Illustris-1模拟的类似分析一致，卫星通常是平均宿主质量密度的较差的示踪剂。与Illustris-1卫星不同，此处的NFW剖面非常适合完整的卫星样品的空间分布。但是，浓度比平均宿主质量密度的浓度低约2倍。 NFW剖面的最亮50％和最微弱的50％的卫星的空间分布也有充分的配置，但是浓度的差异约为2。当样品被主机的颜色和亮度细分时，蓝色卫星的数量密度曲线通常低于平均宿主质量密度曲线，而红色卫星的数量密度曲线通常高于平均宿主质量密度曲线。这些相反的系统偏移结合在一起，在最亮蓝主体的平均质量密度谱与卫星的相应数量密度曲线之间产生适度的一致性。最后，我们根据他们加入主人的红移对卫星进行了细分。由此，我们发现，卫星中最古老的三分之一也没有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 TNG100 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 distribution 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.
