2005A&A...433...31T

We have constructed self-consistent light and mass distribution models for four disk galaxies at redshifts z=0.48, 0.58, 0.81 and 0.88, using the HST archive WFPC2 observations (HDF-S, MDS, Groth Strip survey) and rotation curves measured by Vogt et al. (1996ApJ...465L..15V) and Rigopoulou et al. (2002ApJ...580..789R). The models consist of three components: a bulge, a disk and a dark matter halo. Similarly to the sample studied in Paper I (Tamm & Tenjes, 2003A&A...403..529T), light distribution of the galaxies in the outer parts is clearly steeper than a simple exponential disk. After applying k-corrections, calculated mass-to-light ratios for galactic disks within the maximum disk assumption are M/L_B=0.9, 7.4, 4.3 and 1.4, respectively. Together with the galaxies from Paper I, the mean <M/L_B≥2.5 at <z≥∼0.9, indicating no significant evolution of M/L_B with redshift. Central densities of dark matter halos for an isothermal model are 0.008, 0.035, 0.013, and 0.022 in units M_☉/pc³, respectively. Together with the galaxies from Paper I, the DM central density of the four galaxies at mean readshift <z≥∼0.9 is ρ(0)=(0.012-0.028) M_☉/pc³, also showing no significant evolution with redshift. We have also constructed mass distribution models without assuming flat rotation curves and without a dark matter component. Due to the limited extent of the observed rotation, the models without a dark halo nearly fit the observations. In this case, mass-to-light ratios for the galactic disks are 1.8, 9.7, 12. and 1.9, respectively.