标题： 红移 z=2.363 的星系团 CARLA J0950+2743 以及红移 z=2.243 的 CARLA-Ser J0950+2743 的光谱确认 显示英文标题

标题： Spectroscopic confirmation of the galaxy clusters CARLA J0950+2743 at z=2.363, and CARLA-Ser J0950+2743 at z=2.243

摘要： 星系团是宇宙中最大的引力束缚结构，是研究不同历史时期质量聚集的强大工具。在 z =$>$时，它们不仅为暗物质晕的增长提供了严格的限制条件，还为宇宙年轻时（小于 3.3 Gyr）星系淬灭和形态转变的机制提供了独特的机会。然而，目前确认的$z>2$星系团样本仍然非常有限。 我们展示了星系团 CARLA J0950+2743 在$z=2.363\pm0.005$的光谱确认以及在同一区域偶然发现的新星系团 CARLA-Ser J0950+2743 在$z=2.243\pm0.008$的情况。通过检测 [OII]、[OIII] 和$H\alpha$发射线，我们在第一个星系团中确认了八个恒星形成星系，在第二个星系团中确认了五个。 通过对钱德拉对该区域的意外 X 射线观测分析，发现了一个总亮度为$L_{0.5-5 keV} = 2.9\pm0.6\times10^{45}$erg s$^{-1}$的对应物。鉴于 X 射线观测的深度有限，我们无法从点扩散函数模型中区分源的 1-D 轮廓，但我们的二维轮廓统计分析更倾向于一个扩展组件，这可能与星团际介质（ICM）的热贡献有关。 如果这种弥散的X射线发射是由于炽热的ICM（星系团际介质）引起的，那么这两个星系团的总暗物质质量将是$M_{200}=3.30 ^{+0.23}_{-0.26 (\mathrm{stat})}$ $^{+1.28}_{-0.96 (\mathrm{sys})} \times10^{14} M_{\odot}$。 这使我们的两个星系团成为宇宙学背景下结构增长研究的有趣目标。 然而，未来的研究需要更深入的高分辨率X射线和光谱观测。 显示英文摘要

摘要： Galaxy clusters, being the largest gravitationally bound structures in the Universe, are a powerful tool to study mass assembly at different epochs. At z$>$2 they give an unique opportunity to put solid constraints not only on dark matter halo growth, but also on the mechanisms of galaxy quenching and morphological transformation when the Universe was younger than 3.3 Gyr. However, the currently available sample of confirmed $z>2$ clusters remains very limited. We present the spectroscopic confirmation of the galaxy cluster CARLA J0950+2743 at $z=2.363\pm0.005$ and a new serendipitously discovered cluster, CARLA-Ser J0950+2743 at $z=2.243\pm0.008$ in the same region. We confirm eight star-forming galaxies in the first cluster, and five in the second by detecting [OII], [OIII] and $H\alpha$ emission lines. The analysis of a serendipitous X-ray observation of this field from Chandra reveals a counterpart with a total luminosity of $L_{0.5-5 keV} = 2.9\pm0.6\times10^{45}$ erg s$^{-1}$. Given the limited depth of the X-ray observations, we cannot distinguish the 1-D profile of the source from a PSF model, however, our statistical analysis of the 2-D profile favors an extended component that could be associated to a thermal contribution from the intra-cluster medium (ICM). If the extended X-ray emission is due to the hot ICM, the total dark matter mass for the two clusters would be $M_{200}=3.30 ^{+0.23}_{-0.26 (\mathrm{stat})}$ $^{+1.28}_{-0.96 (\mathrm{sys})} \times10^{14} M_{\odot}$. This makes our two clusters interesting targets for studies of the structure growth in the cosmological context. However, future investigations would require deeper high-resolution X-ray and spectroscopic observations.