Comparing Optical and Near-Infrared Luminosity Functions

The Sloan Digital Sky Survey (SDSS) has measured an optical luminosity function for galaxies in five bands, finding 1.5-2.1 times more luminosity density than previous work. This Letter compares the SDSS luminosity density with two recent determinations of the near-infrared luminosity function based on the 2 Micron All Sky Survey data and finds that an extrapolation of the SDSS results gives a 2.3 times greater near-infrared luminosity density.