Deep Near-Infrared Imaginmg of Galaxies at z > 2 with Subaru: Color and   Magnitude Distribution in HDF-N and the 53W002 Field
  We present the results of the deep NIR imaging observations using the Subaru telescope. At the Hubble Deep Field North, we obtained the new and deepest K'-band image (10 hours) to study the rest-frame optical morphology of galaxies at z > 3 and the stellar mass distribution of galaxies at 2 < z < 4.5. We also study the rest-frame optical properties of the 'building blocks' in the field of 53W002 and overall color distribution there. We then combined these data to compare the color and magnitude distribution in these two fields. The opt-NIR color-magnitude distributions in the two fields looks very similar and we report the conspicuous color change below K_AB =22 and discuss the cause of the feature. 
Toru Yamada, Masaru Kajisawa (National Astronomical Observatory of   Japan)