1.65‐μm ( H ‐band) surface photometry of galaxies – VIII. The near‐IR κ space at z =0

We present the distribution of a statistical sample of nearby galaxies in the κ ‐space ( κ 1 ∝log  M , κ 2 ∝log  I e 3 M / L , κ 3 ∝log  M / L ) . Our study is based on near‐IR ( H ‐band: λ =1.65 μm) observations, for the first time comprising early‐ and late‐type systems. Our data confirm that the mean effective dynamical mass‐to‐light ratio M / L of the E+S0+S0a galaxies increases with increasing effective dynamical mass M , as expected from the existence of the Fundamental Plane relation. Conversely, spiral and Im/BCD galaxies show a broad distribution in M / L with no detected trend of M / L with M , the former galaxies having M / L values about twice larger than the latter, on average. For all the late‐type galaxies, the M / L increases with decreasing effective surface intensity I e , consistent with the existence of the Tully–Fisher relation. These results are discussed on the basis of the assumptions behind the construction of the κ ‐space and their limitations. Our study is complementary to a previous investigation in the optical ( B ‐band: λ =0.44 μm) and allows us to study wavelength dependences of the galaxy distribution in the κ ‐space. As a first result, we find that the galaxy distribution in the κ 1 – κ 2 plane reproduces the transition from bulgeless to bulge‐dominated systems in galaxies of increasing dynamical mass. Conversely, it appears that the M / L of late‐types is higher (lower) than that of early‐types with the same M in the near‐IR (optical). The origins of this behaviour are discussed in terms of dust attenuation and star formation history.