Mass models of 171 galaxies

The rotation curves (RCs) are calculated from the total baryonic matter based on the 3.6{mu}m-band surface photometry, the observed distribution of neutral hydrogen, and the dark halo, in which the three adjustable parameters are the stellar mass-to-light ratio, halo concentration, and virial mass.

Although accounting for a NFW dark halo profile can explain RC observations, the implied c-M_vir_ relation from RC analysis strongly disagrees with that resulting from different cosmological simulations. Also, the M/L-colour correlation of the studied galaxies is inconsistent with that expected from stellar population synthesis models with different stellar initial mass functions. Moreover, we show that the best-fitting stellar M/L ratios of 51 galaxies (30 per cent of our sample) have unphysically negative values in the framework of the {Lambda}CDM theory.