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的星系，它们被认为是在宇宙年龄不到20亿年时通过巨大的尘埃遮蔽的星星形成爆发形成的。椭圆星系通常位于星系团的核心，显示这些星系的形成与星系团的形成有密切的联系，要探测椭圆星系和星系团的形成过程，必须进行远红外至亚毫米和毫米波长的观测，才能“看见”新生恒星经尘埃再处理后发出的星光。卡迪夫大学（CU）是在尘埃宇宙研究的前沿。在过去的几十年里，我们的物理和天文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，这些仪器共同提供了迄今为止最大的尘埃遮蔽星系样本。比如毫米相机麝香（在CU建造）和TolTEC（CU是TolTEC联盟的一部分）在墨西哥的大型毫米望远镜（LMT）上，西蒙斯天文台（Simons Observatory，SO）（CU是SO合作伙伴研究所），仅举几例，将使我们能够扩展对椭圆星系形成的探测（其中几个将引力透镜）和尘埃原星系团的最高红移，并描述现有的和新的来源。在这个项目中，学生将通过对现有和新数据的分析和解释来研究大规模椭圆星系的形成和演化，以及它们所居住的星系团核心。他/她将测量统计特性（计数，光度函数，红移分布等）。的尘埃遮蔽星系和解释的结果，使用物理半分析模型由我们的意大利合作者开发。学生将有助于改进模型，通过在N体模拟中填充暗物质晕与模型方程的输出一致，以生成原椭圆星系和原星系团的大尺度分布的逼真地图。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，并将它们用于未来仪器/天文台的研究预测。在项目期间，学生还将参与编写后续提案，以确定麝香/TolTEC和SO探测到的有趣来源，例如尘埃原星系团和引力透镜尘埃遮蔽星系。

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.