Subaru Deep Survey III. Evolution of Rest-Frame Luminosity Functions Based on the Photometric Redshifts for A K'-band Selected Galaxy Sample

Abstract

We have constructed a very deep K&#39;-selected multicolor BVRIz&#39;JK&#39; sample of 439 field galaxies. Photometric redshifts for sample galaxies were estimated. The overall redshift distribution N(z) for the K&#39;<21.0 sample is consistent with previous observations, and for the first time we derive the N(z) down to K&#39;=24.0. After taking account of the dust extinction and selection effects of the sample, the observed N(z) distribution is well described with the PLE model, while the hierarchical galaxy formation model shows an apparent deficiency of galaxies especially at z>2. The photometric redshift and the best-fit SED model evaluations allow the derivation of the rest-frame K&#39;, B, and UV(2000A) luminosity functions (LFs) and their evolutions. The rest-K&#39; LF shows almost no evolution up to z=3, while the rest B LF shows mild luminosity evolution, and the rest UV LF shows strong luminosity evolution. This trend corresponds to the evolution of the rest UV-K&#39; color, which gets bluer with increasing redshift. We also found that more massive galaxies are redder in this rest-frame color in every epoch. The rest-UV LF of our K&#39;-selected galaxies shows a much shallower faint end slope at z=3 than that of previous estimations for rest-UV selected Lyman break galaxies. As a consequence, the contribution to the global star formation rate of our K&#39;-selected galaxies is about 42% of that derived from the integration of LF of Lyman break galaxies at z=3. This result suggests that a large fraction of the star formation rate density at z>1.5 comes from the contribution from the faint (M_2000A>-20) blue galaxy population at high redshift universe that have not yet obviously been identified. (abridged)