论文标题
老化光环：幅度差距对大量光环的恒星和气体性质的条件统计的影响
Aging Halos: Implications of the Magnitude Gap on Conditional Statistics of Stellar and Gas Properties of Massive Halos
论文作者
论文摘要
冷暗物质模型预测，大规模结构在层次上生长。小型暗物质光环首先形成。然后，它们通过连续合并和积聚逐渐生长。这些光环以热气和冷恒星相的形式拥有宇宙中的大多数男性物质。确定重生子如何分配到这些阶段，需要对星系形成及其组装历史的详细建模。据推测，同一质量光环的形成时间可能与其重子含量相关。为了评估这一假设，我们采用质量的光环高于$ 10^{14} \，m _ {\ odot} $由tng300 tng300解决方案实现的。地层时间不是直接观察的。因此，我们依赖于最亮的最亮的光环星系成员之间的幅度差距，这表明轨迹的形成时间是宿主光环的时间。我们计算出阳极晕恒星和气体含量的条件统计，以其总质量和幅度间隙为条件。我们发现幅度间隙与气体质量，BCG恒星质量和卫星星系恒星质量之间存在很强的相关性，但没有光晕的总恒星质量。在幅度差距上的调节可以减少围绕光环属性的散射 - 直到质量关系，并对条件协方差产生重大影响。散射的减少可能高达30％，这意味着更准确的光晕质量预测。结合幅度差距具有使用光环丰度改善宇宙学约束的潜力，并使我们能够深入了解这些系统内的巴里昂演化。
Cold dark matter model predicts that the large-scale structure grows hierarchically. Small dark matter halos form first. Then, they grow gradually via continuous merger and accretion. These halos host the majority of baryonic matter in the Universe in the form of hot gas and cold stellar phase. Determining how baryons are partitioned into these phases requires detailed modeling of galaxy formation and their assembly history. It is speculated that formation time of the same mass halos might be correlated with their baryonic content. To evaluate this hypothesis, we employ halos of mass above $10^{14}\,M_{\odot}$ realized by TNG300 solution of the IllustrisTNG project. Formation time is not directly observable. Hence, we rely on the magnitude gap between the brightest and the fourth brightest halo galaxy member, which is shown that traces formation time of the host halo. We compute the conditional statistics of the stellar and gas content of halos conditioned on their total mass and magnitude gap. We find a strong correlation between magnitude gap and gas mass, BCG stellar mass, and satellite galaxies stellar mass, but not the total stellar mass of halo. Conditioning on the magnitude gap can reduce the scatter about halo property--halo mass relation and has a significant impact on the conditional covariance. Reduction in the scatter can be as significant as 30%, which implies more accurate halo mass prediction. Incorporating the magnitude gap has a potential to improve cosmological constraints using halo abundance and allows us to gain insight into the baryon evolution within these systems.
