Comparing Optical and Near Infrared Luminosity Functions

The Sloan Digital Sky Survey [SDSS] has measured an optical luminosity function for galaxies in 5 bands, finding 1.5 to 2.1 times more luminosity density than previous work. This note compares the SDSS luminosity density to two recent determinations of the near infrared luminosity function based on 2MASS data, and finds that an extrapolation of the SDSS results gives a 2.3 times greater near infrared luminosity density.