论文标题
关于星系组和簇中群内光的质量分布
On the Mass Distribution of the Intra-Cluster Light in Galaxy Groups and Clusters
论文作者
论文摘要
我们利用了一个半分析模型，它具有最先进的群体内光（ICL）的形成，以研究不同红移在星系组和簇中ICL的质量分布。我们假设ICL遵循不同浓度的NFW配置文件，通过关系$ c_ {icl} =γc_{dm} $链接到暗物质，其中参数$γ$设置为重现最明亮的集群Galaxy（BCG）和ICL中观察到的观测的关系（$ m^*_ {100} -m_ {500} $），$ z = 0 $。然后，该模型对几个理论和观察结果进行测试，从当前时间到$ z \ sim1.5 $。我们的分析表明，最内向的100 kpc内BCG和ICL中恒星质量的比例是红移，参数$γ$的越来越多的功能，以及晕halo质量的减小功能。匹配观察到的$ m^*_ {100} -m_ {500} $是$γ= 3 $ at $ z = 0 $所需的$γ$的值，但有暗示它可能是红速和光晕质量的函数。该结果表明，ICL的分布比暗物质浓缩更集中，但比其他研究先前发现的浓缩少。我们建议NFW的修改版本是对分组和簇中弥漫光的分布的很好描述，这使ICL成为暗物质的可靠示踪剂，与最近的观察结果一致。
We take advantage of a semi-analytic model with a state-of-art implementation of the formation of the intra-cluster light (ICL) to study the mass distribution of the ICL in galaxy groups and clusters, at different redshifts. We assume the ICL to follow a NFW profile with a different concentration, linked to that of the dark matter by the relation $c_{ICL}=γc_{DM}$, where the parameter $γ$ is set to reproduce the observed relation between the stellar mass in the brightest cluster galaxy (BCG) and ICL in the innermost 100 kpc and the halo mass ($M^*_{100}-M_{500}$), at $z=0$. The model is then tested against several theoretical and observational results, from the present time to $z\sim1.5$. Our analysis shows that the fraction of stellar mass in the BCG and ICL within the innermost 100 kpc is an increasing function of redshift, parameter $γ$, and a decreasing function of the halo mass. The value of $γ$ required to match the observed $M^*_{100}-M_{500}$ is $γ=3$ at $z=0$, but there are hints that it might be a function of redshift and halo mass. This result indicates that the distribution of the ICL is more concentrated than the dark matter one, but less concentrated than previously found by other studies. We suggest that a modified version of the NFW is a good description of the distribution of the diffuse light in groups and clusters, which makes the ICL a reliable tracer of the dark matter, in good agreement with recent observational findings.
