The Hawaii+Anglo‐Australian Observatory K ‐Band Galaxy Redshift Survey. I. The Local K ‐Band Luminosity Function

Abstract

We present the K-band local luminosity function derived from a sample of 1056 bright (K<15) K-selected galaxies from the Hawaii+Anglo-Australian Observatory (AAO) K-band redshift survey. The Hawaii+AAO K-band redshift survey covers four equatorial fields with a total area of 8.22 deg2. We derive both the nonparametric and Schechter luminosity function from our data and determine M*(K)=-23.70+/-0.08+5log10(h), α=-1.37+/-0.10, and φ*=0.013+/-0.003h3Mpc-3 for a universe with Ωm=0.3 and ΩΛ=0.7. We also measure the K-band luminosity function for the early- and later type galaxies from our morphologically classified subsample. It appears that later type galaxies have a fainter M* and a steep slope, while early-type galaxies have a much brighter M* and a quite flat slope in their K-band luminosity functions. This is consistent with what has been found in optical-type dependent luminosity function. The K-band luminosity density derived using our luminosity function is now measured at a similar redshift depth to optical luminosity densities in the Sloan Digital Sky Survey redshift survey. It is 2 times higher than the previous measurement from the shallower 2MASS sample and resolves the previously reported discrepancies between optical and near-infrared luminosity densities.