论文标题
最亮星系星系及其宿主簇的共同进化
Co-evolution of the Brightest Cluster Galaxies and their Host Clusters in IllustrisTNG
论文作者
论文摘要
我们使用Illustristng模拟来探索大量簇与其中央星系（BCG）之间的动态缩放关系。我们使用的Illustris TNG300-1模拟包括280个大型群集，其中$ M_ {200}> 10^{14} $ M $ _ {\ odot} $启用可靠的统计分析。我们得出了BCGS恒星粒子（$σ_{*，BCG} $）的视线速度分散，类似于观察到的BCG恒星速度分散体。我们还计算了subhalo速度分散，以测量群集速度分散（$σ_{Cl} $）。 $σ_ {*，bcg} $和$σ_{cl} $都与群集光环质量成比例，但斜率略有不同。因此，就像观察到的关系一样，$σ_ {*，bcg} /σ_{cl} $会偏向于$σ_{cl} $的函数，但散点很大。我们探索$σ_{*，bcg} - σ_{cl} $缩放关系的红移演变，以$ z \ Lessim 1 $ 1 $的比例关系，可以直接与观察值进行比较。缩放关系在高红移时具有相似的斜率，但是由于$σ_ {*，bcg} $中的散布较大，散布会增加。模拟表明，高红移BCG在动态上比其低红移对应物更为复杂。
We use the IllustrisTNG simulations to explore the dynamic scaling relation between massive clusters and their central galaxies (BCGs). The Illustris TNG300-1 simulation we use includes 280 massive clusters with $M_{200} > 10^{14}$ M$_{\odot}$ enabling a robust statistical analysis. We derive the line-of-sight velocity dispersion of the stellar particles of the BCGs ($σ_{*, BCG}$), analogous to the observed BCG stellar velocity dispersion. We also compute the subhalo velocity dispersion to measure the cluster velocity dispersion ($σ_{cl}$). Both $σ_{*, BCG}$ and $σ_{cl}$ are proportional to the cluster halo mass, but the slopes differ slightly. Thus like the observed relation, $σ_{*, BCG} / σ_{cl}$ declines as a function of $σ_{cl}$, but the scatter is large. We explore the redshift evolution of $σ_{*, BCG} - σ_{cl}$ scaling relation for $z \lesssim 1$ in a way that can be compared directly with observations. The scaling relation has a similar slope at high redshift, but the scatter increases because of the large scatter in $σ_{*, BCG}$. The simulations imply that high redshift BCGs are dynamically more complex than their low redshift counterparts.
