Abstract
We present multi-wavelength observations of a forming cluster around the z=2.16 radio galaxy MRC 1138-262. We study the populations of Ly alpha and H alpha emitters, extremely red objects and X-ray sources. The field of the radio source MRC 1138-262 has been observed at several wavelengths, including deep imaging through narrow band filters corresponding to Ly alpha and H alpha at z ~ 2.16 (with FORS and ISAAC respectively), several optical and near-IR broad bands (B, R, I, J, H and K), and finally radio and X-ray emission.
