Composite near-infrared and X-ray image of the galaxy cluster CL J1449+0856
This image shows the X-ray emission (in purple) coming from the diffuse intra-cluster medium of the galaxy cluster CL J1449+0856 as detected by XMM-Newton.
The X-ray signal is superimposed onto a composite image of very long exposures taken at near-infrared wavelengths with ESO's Very Large Telescope in Chile and the Subaru telescope on Hawaii. Most of the objects visible in the field are very faint and distant galaxies: the galaxy cluster is visible as a clump of faint, red objects near the centre.
Located at a redshift z~2, CL J1449+0856 is the most distant mature cluster ever detected.
The cluster luminosity (L) is approximately
The region depicted above is about 100 arc minutes on a side.