We present results from our multi-wavelength study of SG1120 , a super galaxy group at z = 0.37 that will merge to form a galaxy cluster comparable in mass to Coma .
We have spectroscopically confirmed 174 members in the four X-ray luminous groups that make up SG1120 , and these groups have velocity dispersions of \sigma _ { 1 D } = 303 - 580 km s ^ { -1 } .
We find that the supergroup has an excess of 24 \mu m members relative to CL 1358+62 , a rich galaxy cluster at z = 0.33 .
SG1120 also has an increasing fraction of 24 \mu m members with decreasing local galaxy density , i . e . an infrared-density relation , that is not observed in the rich cluster .
We detect nine of the group galaxies in VLA 1.4 Ghz imaging , and comparison of the radio to total infrared luminosities indicates that \sim 30 % of these radio-detected members have AGN .
The radio map also reveals that one of the brightest group galaxies has radio jets .
We are currently analysing the 1.4 Ghz observations to determine if AGN can significantly heat the intrahalo medium and if AGN are related to the excess of 24 \mu m members .