Far Infrared Luminosity Function of Local Star-forming Galaxies in the AKARI Deep Field South

TL;DR

This paper derives the local universe's far-infrared galaxy luminosity function using AKARI data, spectroscopic redshifts, and optical identifications, distinguishing star-forming and AGN galaxies, and compares results with previous surveys and models.

Contribution

It provides a new far-infrared luminosity function for local galaxies based on AKARI data, including separation by galaxy activity type, and compares with prior surveys and models.

Findings

Luminosity function agrees with previous ISO survey results.

Separates star-forming and AGN galaxy contributions.

Consistent with IRAS-based evolution models.

Abstract

We present a far-infrared galaxy luminosity function for the local universe. We have obtained 389 spectroscopic redshifts for galaxies observed at 90 microns in the AKARI Deep Field South, using the AAOmega fibre spectrograph via optical identifications in the digitized sky survey and 4m-class optical imaging. For the luminosity function presented in this paper, we have used those galaxies which have redshifts 0<z<0.25, have optical magnitudes and are not part of a newly discovered cluster of galaxies (giving a total of 130 sources). Infrared and optical completeness functions were estimated using earlier Spitzer data and APM B-band optical data respectively, and the luminosity function has been prepared using the 1/Vmax method. We also separate the luminosity function between galaxies which show evidence of predominantly star-forming activity and predominantly active galactic nucleus (AGN) activity in their optical spectra. Our luminosity function is in good agreement with the previous 90 micron luminosity function from the European Large Area ISO Survey, and we also present a luminosity function with combined AKARI and ISO data. The result is in reasonable agreement with predictions based on the earlier IRAS 60 micron PSC-z catalogue, and with a recent backward evolution model.