Dark Matter Map in Galaxy Cluster Abell 1689

This is the Hubble Space Telescope image of the inner region of Abell 1689, an immense cluster of galaxies located 2.2 billion light-years away. Dark matter in the cluster is mapped by plotting the plethora of arcs produced by the light from background galaxies that is warped by the foreground cluster's gravitational field. Dark matter cannot be photographed, but its distribution is shown in the blue overlay. The dark matter concentration and distribution is then used to better understand the nature of dark energy, a pressure that is accelerating the expansion of the universe. The imaging data used in the natural-color photo was taken in 2002 with Hubble's Advanced Camera for Surveys.

About the colours

This image is a composite of separate exposures acquired by the ACS instrument on the Hubble Space Telescope (HST). Several filters were used to sample broad wavelength ranges. The color results from assigning different hues (colors) to each monochromatic (grayscale) image associated with an individual filter. In this case, the assigned colors are: Blue: Dark Matter Map + F475W (g) Green: F775W (i) Red: F850LP (z)

About the data

ACS/WFC data of Abell 1689 were observed with the HST proposal 9289 : H. Ford and N. Benitez (Johns Hopkins University), and T. Broadhurst (Tel Aviv University).

The science team for this release includes: E. Jullo (Jet Propulsion Laboratory), P. Natarajan (Yale University), J.-P. Kneib (Laboratoire d'Astrophysique de Marseille, CNRS, France), A. D'Aloisio (Yale University), M. Limousin (Laboratoire d'Astrophysique de Marseille and University of Copenhagen, Denmark), J. Richard (Durham University, U.K.), and C. Schimd (Laboratoire d'Astrophysique de Marseille, CNRS, France).