Optical Observations of the ACT Sky Region

University Of Pittsburgh, Pittsburgh PA

Investigators

Abstract

AST-0546035 Kosowsky This project is part of a larger effort to reduce and analyze the data from a drift scan survey in four bands using the new Southern African Large Telescope (SALT), in an area chosen to cover the same sky region as the forthcoming Atacama Cosmology Telescope (ACT) microwave background maps. By making a galaxy catalog from these scans, it will be possible to determine photometric redshifts, and to choose cluster members for spectroscopic follow-up, both of which will add considerable value to the ACT observations of galaxy clusters via the Sunyaev-Zel'dovich distortion. Galaxy clusters can provide strong constraints on the growth of structure, including the neutrino mass and the dark energy equation of state, and this research helps to provide the optical data necessary to exploit the ACT clusters fully for cosmology, and constrain the recent expansion history of the Universe. This will be a high-visibility project for the SALT telescope, raising the profile of SALT in particular and science in Africa in general, and leading to expanded collaborative and scientific opportunities for African students and researchers. It also involves student researchers, and connects to ACT efforts in Chile.