Collaborative Research: Evolution of Cosmic Structure and of the Galactic Spheroid Population

University Of California-Santa Cruz, Santa Cruz CA

Investigators

Abstract

AST-1010033/1009908 Primack/Klypin The majority of the stellar mass in the Universe lies in galactic spheroids, which also host supermassive black holes (SMBH). The origin of these key structures can be clarified through the interplay of new multi-wavelength survey observations and improved theory, essential for guiding and interpreting the observations. This research focuses on the growth of cosmic structure and on the two opposing effects of early, efficient star formation, and the quenching of this process in massive dark-matter halos, which together govern the formation of blue and red galaxies. This project should discriminate between galaxy spheroid buildup by cold gas inflows and disk instabilities and the alternative of major and minor mergers. The work should also identify the roles of nuclear activity versus virial shock heating in halos above a threshold mass, distinguish satellite from central quenching, and understand the cross-talk between the shutdown of star formation and the development of spheroidal stellar components and SMBHs. Detailed models of early-type galaxy formation will be compared with observations of mergers and other processes out to high redshifts, and also of nearby galaxies whose properties can be studied in detail. The work is supported by a large program of recently completed and planned follow-on computer simulations, using the most up-to-date cosmological parameters and having high mass and spatial resolution. Additional high-resolution hydrodynamic simulations will clarify galaxy formation processes and permit the calculation of kinematics, spectra and images, including dust scattering and absorption. It is crucial that simulations are 'observed' in ways that accurately mimic observations of real galaxies. The team will involve students from underrepresented groups in astrophysical theory research, including the ability to understand the implications of the latest observations. This work pushes the computational envelope, and all codes and outputs will be available to the astrophysical community. Planned computer visualizations will help to understand the simulations while simultaneously making the results accessible to other researchers and to the public.