The majority of the stellar mass in the Universe today resides in galaxies with two primary structural components (bulge and disk). In this work, we use the largest contiguous HST imaging region (COSMOS), the Deep Extragalactic VIsible Legacy Survey (DEVILS), and the galaxy structural fitting code {\sc ProFit}, to deconstruct ∼35,000 galaxies into their sub-structures. We use this sample to determine the stellar mass density (SMD) sub-divided by structural components and its evolution since z=1. We find that the majority of stellar mass at all epochs lies in disk-like structures. The SMD in the disk population increases in z=1−0.35 and stabilizes/decreases to z=0 (contributing ∼60% to the total SMD at z=1 and declining to ∼30%at z=0). This decline is countered by a rapid rise of the SMD in pseudo-bulge population and a consistent growth of spheroidal structures (classical bulges and ellipticals) with significant stellar mass growth in z=1−0.35 and a somewhat flattened trend to z=0. While the physical mechanisms for this are not obvious, the results are consistent with a transition from a Universe dominated by disk growth, to a Universe in which pseudo-bulges are emerging and spheroids are growing. Further study is required before this can be apportioned to internal secular processes, gas accretion, minor and major mergers. However, it is clear that since z=0.35 the processes mentioned above now dominate over quiescent disk growth as the cosmic star-formation history declines.
Deep Extragalactic VIsible Legacy Survey (DEVILS): The emergence of bulges and decline of disk growth since z=1, Abdolhosein Hashemizadeh, Simon P. Driver, Luke J. M. Davies, Aaron S. G. Robotham, Sabine Bellstedt, Rogier A. Windhorst, Matt Jarvis, Benne W. Holwerda, Malgorzata Siudek, Caroline Foster, Steven Phillipps, Jessica E. Thorne, Christian Wolf, arXiv:2203.00185