Research Gallery

Image of the gravitational lens RXJ1131−1231, taken with the Advanced Camera for Surveys on the Hubble Space Telescope. The lensed AGN images of the spiral source galaxy are marked by A, B, C, and D, and the star forming regions of the spiral galaxy form the spectacular lensed structures. The primary and satellite lens galaxies are indicated by G and S, respectively. The cosmological time-delay distance to the lens, which is primarily sensitive to the Hubble constant, can be measured by obtaining the time delays between the multiple images and modeling the mass distributions of the lens galaxies and line-of-sight structures.