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

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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.