Atacama Cosmology Telescope Shadows and Optical Telescope Images (image) Rutgers University Share Print E-Mail Caption Four Atacama Cosmology Telescope (ACT) images of cosmic background radiation, top row, with dark blue colors indicating "shadows" cast by galaxy clusters. Below, four optical images of the galaxy clusters, with white contour lines corresponding to the cosmic background radiation intensity levels in the ACT images. Credit top row: Tobias Marriage, Johns Hopkins University, Princeton University. Bottom matrix: Felipe Menanteau, Rutgers University Usage Restrictions Permission is granted to reproduce the image in connection with news coverage of this story. All other rights are reserved. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.