Investigating the formation and evolution of the most massive galaxies and galaxy clusters in the Universe

椭圆星系是我们今天在宇宙中观察到的最大质量的星系，它们被认为是在宇宙不到20亿年的时候，通过一次巨大的尘埃形成的恒星爆发而形成的。椭圆星系通常位于星系团的核心，这表明这些星系的形成与星系团的形成之间有着密切的联系。要探测椭圆星系和星系团的形成过程，需要在远红外到亚毫米和毫米波长进行观测，以便“看到”新生恒星发出的尘埃再处理的星光。卡迪夫大学(CU)在尘埃宇宙的研究中走在了前列。在过去的几十年里，我们的物理和天文学学院为赫歇尔空间天文台和Scuba-2相机等仪器的建设和数据开发做出了关键贡献，这些仪器一起提供了迄今为止最大的尘埃遮挡星系样本。即将建立的新设施，如墨西哥大毫米望远镜(LMT)上的毫米相机Muscat和Toltec(CU是Toltec财团的一部分)，以及智利的西蒙斯天文台(So)(CU是So合作研究所)，这将使我们能够将正在形成的椭圆体(其中几个将被引力透镜)和尘埃原星团的探测扩展到最高的红移，并表征现有的和新的来源。在这个项目中，学生将通过对现有和新数据的分析和解释，研究大质量椭圆形的形成和演化，以及它们所居住的星系团核心的形成和演化。他/她将测量统计特性(数量计数、光度函数、红移分布等)。并使用我们的意大利合作者开发的物理半解析模型来解释结果。学生将通过在N-Body模拟中填充与模型方程的输出一致的暗物质晕来改进模型，以便生成原始椭圆体和原始星系团的大范围分布的逼真地图。然后，他/她将把这些地图与观测结果进行比较，以进一步约束模型，并将它们用于预测未来仪器/天文台的研究。在项目期间，学生还将撰写后续建议，以描述利用马斯喀特/托尔特克等探测到的有趣来源，如尘埃原星团和引力透镜尘埃遮挡的星系。

Elliptical galaxies are the most massive galaxies we observe in the Universe today and they are believed to have formed via a giant dust-obscured burst of star formation when the Universe was less than 2 billion years old. Elliptical galaxies are usually found in the core of galaxy clusters, suggesting a close link between the formation of those galaxies and that of galaxy clusters.Detecting elliptical galaxies and galaxy clusters in their forming process requires observations at far-infrared to sub-millimetre and millimetre wavelengths in order to "see" the dust-reprocessed starlight from the new born stars. Cardiff University (CU) is at the forefront in the study of the dusty Universe. Over the past decades our School of Physics and Astronomy has provided a key contribution to both the construction and the data exploitation of instruments like the Herschel space observatory and the SCUBA-2 camera, which, together, have delivered the largest samples of dust-obscured galaxies to date.New upcoming facilities, like the millimetre cameras MUSCAT (built at CU) and TolTEC (CU is part of the TolTEC consortium) on the Large Millimetre Telescope (LMT) in Mexico, and the Simons Observatory (SO) in Chile (CU is an SO partner Institute), just to cite a few, will allow us to extend the detection of forming ellipticals (several of which will be gravitationally lensed) and of dusty proto-clusters out to the highest redshifts and to characterize both existing and new sources. In this project, the student will investigate the formation and evolution of massive ellipticals, and of the cluster core they inhabit, by contributing to the analysis and interpretation of both existing and new data. He/she will measure the statistical properties (number counts, luminosity functions, redshift distributions etc.) of dust-obscured galaxies and interpret the results using a physical semi-analytic model developed by our Italian collaborators. The student will contribute to improving the model, by populating dark matter halos in N-body simulations consistently with the output of the equations of the model in order to generate realistic maps of the large scale distribution of proto-ellipticals and proto-clusters. He/she will then compare such maps with observations to further constrain the model and will use them to make forecasts for studies with future instruments/observatories.During the project the student will also contribute to the writing of follow-up proposals to characterise interesting sources detected with MUSCAT/TolTEC and SO, such as dusty proto-clusters and gravitationally lensed dust-obscured galaxies.