Newtonian acceleration scales in spiral galaxies




We revisit the issue of the constancy of the dark matter (DM) and baryonic Newtonian acceleration scales within the DM scale radius by considering a large sample of late-type galaxies. We rely on a Markov Chain Monte Carlo method to estimate the parameters of the halo model and the stellar mass-to-light ratio and then propagate the uncertainties from the rotation curve data to the estimate of the acceleration scales. This procedure allows us to compile a catalogue of 58 objects with estimated values of the B-band absolute magnitude MB, the virial mass Mvir, and the DM and baryonic Newtonian accelerations (denoted as gDM(r0) and gbar(r0), respectively) within the scale radius r0 which we use to investigate whether it is possible to define a universal acceleration scale. We find a weak but statistically meaningful correlation with Mvir thus making us argue against the universality of the acceleration scales. However, the results somewhat depend on the sample adopted so that a careful analysis of selection effects should be carried out before any definitive conclusion can be drawn.