The Morphological Type Dependence of K-band Luminosity Functions

TL;DR

This study presents K-band luminosity functions for nearby galaxies, revealing how different morphological types contribute differently to the luminosity density, with implications for understanding stellar mass distribution.

Contribution

It provides the first detailed K-band luminosity functions segregated by galaxy morphology for a complete local sample.

Findings

Late-type spirals follow a power-law luminosity function.

Ellipticals and bulge-dominated galaxies have peaked luminosity functions.

All morphological types contribute roughly equally to local luminosity density.

Abstract

Differential 2.2um (K-band) luminosity functions are presented for a complete sample of 1570 nearby Vgsr < 3000 km/s, where Vgsr is the velocity measured with respect to the Galactic standard of rest), bright (K < 10 mag), galaxies segregated by visible morphology. The K-band luminosity function for late-type spirals follows a power law that rises towards low luminosities whereas the K-band luminosity functions for ellipticals, lenticulars and bulge-dominated spirals are peaked with a fall off at both high and low luminosities. However, each morphological type (E, S0, S0/a-Sab, Sb-Sbc, Sc-Scd) contributes approximately equally to the overall K-band luminosity density in the local universe, and by inference, the stellar mass density as well.