The formation and evolution of high-redshift massive galaxies is a hotspot in extra-galactic astronomy. In the study of the growth of galaxies it is crucial to investigate both the evolution in the physical scale (i.e., morphology) as well as in stellar mass, with redshfit. A special and important class of high redshift galaxies has been found recently, characterised by high surface density of stellar mass, that is, massive compact galaxies. From observations, there are two different categories for high-redshift compact galaxies: compact star-forming galaxies (cSFGs, also called ‘blue nuggets’), and compact quiescent galaxies (cQGs, also called ‘red nuggets’). Unlike what found in the local universe, massive compact galaxies are ubiquitous during early epochs.

The aim of this thesis, carried out by the candidate at the University of Nanjing, is to understand how compact massive galaxies form and evolve, and what causes the redshift evolution of their number density.

The candidate, Ms. Shiying LU, will pass two years in Saclay funded by a CSC bourse to work at her PhD project in collaboration with E. Daddi's group in LCEG. In this framework she will extend her research with the participation to surveys using the soon-to-be-launched JWST observatory and also explore forming cluster environments.