Observational Cosmology, Gravitational Lensing, and Astrophysics Group

The astrophysics and observational cosmology group is active in a variety of projects involving the study of galaxy clusters, individual galaxies, sheets and voids in the galaxy distribution, and large-scale structure in general. The fundamental links between all these lines of research are that they provide clues to the nature of the dark matter and energy as well as measuring the fundamental parameters of cosmology.


Our group is leading the Local Volume Complete Cluster Survey (LoVoCCS), a survey of the all the most massive galaxy clusters in the local Universe.  LoVoCCS is using the Dark Energy Camera on the Blanco 4-meter telescope on Cerro Tololo to measure the galaxy population and the dark matter structure (via weak gravitational lensing) in these clusters.  This will provide a census of the dark matter substructure and galaxy transformations that are taking place at the current day, and provide a stepping stone to the study of the evolution of these clusters in the more distant Universe with the Vera Rubin Observatory’s Large Survey of Space and Time (LSST) and the Nancy Grace Roman Space Telescope.

Rubin Observatory LSST DESC

Our group is central to the LSST Dark Energy Science Collaboration’s  (DESC) Galaxy Clusters Group.  Dell’Antonio served as lead of the group from 2012 until 2018.  Within DESC, our group is leading the effort to calibrate the lensing shear measurements in the Cluster environment, accounting for the difference between shear and distortion and effects of blending on shear and photometric redshifts.  Our group is also part of the DESC Blending, Clusters, and Low Surface Brightness (LSB) groups.  We are working towards the beginning of science operations in 2024.