Nearby Galaxies in the 2micron All Sky Survey I. K-band Luminosity
  Functions
  Differential K-band luminosity functions (LFs) are presented for a complete
sample of 1613 nearby bright galaxies segregated by visible morphology. The LF
for late-type spirals follows a power law that rises towards low luminosities
whereas the LFs for ellipticals, lenticulars and bulge-dominated spirals are
peaked and decline toward both higher and lower luminosities. Each
morphological type (E, S0, S0/a-Sab, Sb-Sbc, Sc-Scd) contributes approximately
equally to the overall K-band luminosity density of galaxies in the local
universe. Type averaged bulge/disk ratios are used to subtract the disk
component leading to the prediction that the K-band LF for bulges is bimodal
with ellipticals dominating the high luminosity peak, comprising 60% of the
bulge luminosity density in the local universe with the remaining 40%
contributed by lenticulars and the bulges of spirals. Overall, bulges
contribute 30% of the galaxy luminosity density at K in the local universe with
spiral disks making up the remainder. If bulge luminosities indicate central
black hole masses, then our results predict that the black hole mass function
is also bimodal.
