论文标题
在重力镜头群集SMACS j0723.3-7327 z = 0.39的第一个JWST图像中检测簇内球状簇的检测
Detection of Intracluster Globular Clusters in the First JWST Images of the Gravitational Lens Cluster SMACS J0723.3-7327 at z = 0.39
论文作者
论文摘要
我们根据早期发布的JWST/NIRCAM图像，对大型引力镜头群SMACS j0723.3-7327进行了对球状簇（GCS）的调查。在该点源的颜色磁性图中，我们发现大量的群内GC群传播在群集的广泛区域中。考虑到簇红移的年龄，年龄在9.5 Gyr中。这些GCS的F200W（AB）幅度为$ 26.5 <{F200W_0} <29.5 $ mag，对应于$ -15.2 <{M_ {M_ {F200W}} <-12.2 $ MAG，表明它们属于最明亮的GCS（包括超级典型的GCS（包括Ultraccompact dwarfs）。这些GC的空间分布显示出沿最亮星系星系的主要轴线拉长的巨型尺度结构。此外，它们显示了大量的子结构，其中一些与散布内光的地图中看到的子结构一致。通常，基于文献中强透镜分析，GC数密度图与暗物质质量密度图相一致。外部区域中GC的径向数密度谱比从镜头模型获得的暗物质质量谱陡峭。这些结果与Abell 2744的深HST图像中发现的GC（$ Z = 0.308 $）以及模拟的Galaxy簇中的GC相一致。这表明，群内GC是一个出色的独立工具，可以探测星系簇中的暗物质分布，并揭示JWST时代的集群组装历史。
We present a survey of globular clusters (GCs) in the massive gravitational lens cluster SMACS J0723.3-7327 at $z=0.39$ based on the early released JWST/NIRCam images. In the color-magnitude diagrams of the point sources we find clearly a rich population of intracluster GCs that spread in a wide area of the cluster. Their ages, considering the cluster redshift, are younger than 9.5 Gyr. The F200W (AB) magnitudes of these GCs, $26.5<{F200W_0} <29.5$ mag, correspond to $-15.2<{M_{F200W}} <-12.2$ mag, showing that they belong to the brightest GCs (including ultracompact dwarfs). The spatial distributions of these GCs show a megaparsec-scale structure elongated along the major axis of the brightest cluster galaxy. In addition, they show a large number of substructures, some of which are consistent with the substructures seen in the map of diffuse intracluster light. The GC number density map is, in general, consistent with the dark matter mass density map based on the strong lensing analysis in the literature. The radial number density profile of the GCs in the outer region is steeper than the dark matter mass profile obtained from lensing models. These results are consistent with those for the GCs found in the deep HST images of Abell 2744, another massive cluster at $z=0.308$, and in simulated galaxy clusters. This shows that the intracluster GCs are an excellent independent tool to probe the dark matter distribution in galaxy clusters as well as to reveal the cluster assembly history in the JWST era.
