Program: GN-2008B-Q-37

It has become clear over the past few years that at least some massive galaxies formed very early in the history of the universe. However, at least at z > 2, these galaxies look quite different from local massive galaxies: they tend to be quite compact, and, when they are extended enough to allow the determination of a radial profile, they tend to look like disks rather than spheroids. However, our sample is still quite small. We propose to continue our program of identification and characterization of spectral-energy distributions of these galaxies. We request 6 hours of Gemini N NIRI time for near-IR imaging of the 2 remaining fields of ultra-steep-spectrum 4C radio sources with 2.8 < z < 3.6, which bridge the range between our z ~ 2.5 sample and our z ~ 3.8 sample. These observations support current NSF and Spitzer programs.