K-band Luminosity Functions of IllustrisTNG300-1 Galaxies

Abstract

This Research Note summarizes preliminary results, presented at the 238th AAS meeting, for the K-band luminosity functions (LFs) of IllustrisTNG300-1 galaxies. For MK ≥ −22, the simulation reproduces both the shape and amplitude of the LF for observed field galaxies. However, it significantly overproduces field galaxies with MK < −22. For MK ≤ −22, the simulation reproduces the shape of the LF for observed cluster galaxies, however at fainter magnitudes the LF falls below a simple extrapolation of recent observations. For MK ≤ −22, the shapes of the LFs for red cluster galaxies and blue cluster galaxies agree reasonably well with observations, but neither is well-fitted by a Schechter function at fainter magnitudes. In addition, the faint-end slope of the LF in the inner regions of the clusters is significantly flatter than it is in the outer regions.