Galaxy morphology: how the growth of their bulge shapes the evolution of galaxies —

Almost a century after the publication of the Hubble sequence (Hubble 1926), that classifies galaxies according to their shapes and features, galaxy morphology remains a topical issue. Indeed, the structure of galaxies provide insight on how they acquire their mass, grow their stellar populations, and eventually cease their star formation. After presenting how galaxy images can be analysed to characterize their morphologies, I will describe how the properties of bulges and disks vary along the Hubble sequence, and how galaxies of diverse morphologies are distributed across the colour-mass diagram, as well as across various key scaling relations. This will highlight how morphological transformations, and especially the growth of the bulge, can be connected to their star-forming history. Then, I will discuss how the capabilities of ESA’s latest space telescope Euclid, launched in July 2023, can be leveraged to retrace the history of the Hubble sequence, and I will present the first strides made in that avenue of research, through the build-up of an unprecedented morphological catalogue, and the first analyses of galaxy morphology across cosmic times and along the Cosmic Web.