This multi-colored haze is actually two colliding galaxy clusters that are forming a single object known as MACS J0416.1-2403 (or MACS J0416 for short). It’s located about 4.3 billion light-years from Earth. This image combines data from three different telescopes: the Hubble Space Telescope (showing the galaxies and stars), the Chandra X-ray Observatory (diffuse emission in blue), and the NRAO Very Large Array (diffuse emission in pink). Each telescope shows a different element of the cluster.
As with all galaxy clusters, MACS J0416 contains a significant amount of dark matter which leaves a detectable imprint in visible light by distorting the images of background galaxies. In this image the dark matter appears to align well with the blue-hued hot gas, suggesting that the two clusters have not yet collided. If the clusters had already merged, the dark matter and gas would have separated.
Image credit: NASA / ESA / CXC / NRAO-AUI-NSF /STScI / G. Ogrean (Stanford University)