We present the first results of a narrow-band photometric study of the massive galaxy cluster XMMU J2235.3-2557 at z=1.39. We obtained deep H narrow-band imaging with the Near InfraRed Imager and Spectrometer on Gemini North, corresponding to H{alpha} emission at the cluster's redshift. Our sample consists of 82 galaxies within a radius of ~500kpc, 10 of which are spectroscopically confirmed cluster members. 16 galaxies are identified as excess line-emitters.
Cone search capability for table J/MNRAS/411/2009/table1 (Properties of all objects detected in the H-narrow image of the central ~500kpc of the massive galaxy cluster XMMU J2235.3-2557 at z=1.39)