Galaxy Cluster XMMU J2235.3-2557
The distant, massive galaxy cluster as it existed when the Universe was less than 5 billion years old or 1/3 its present age. This is a colour composite image of an XMM-Newton X-ray image (orange channel, blinking) and ESO-VLT optical/near-infrared images (red, green, and blue channels).
Old cluster galaxies are the small red objects and the diffuse, hot gas is revealed by the X-ray emission. The field-of-view is 2.8' x 2.8', corresponding to 1.4 Mpc x 1.4 Mpc at the cluster redshift.
Orange channel: XMM-Newton soft X-ray image (0.5-2.0 keV, 45ks).
Red channel: VLT-ISAAC Ks-band image (3600s); the green channel: VLT-FORS2 z-band image (480s); the blue channel: VLT-FORS2 R-band image (1140s).