The radial tully-fisher relations in dwarf spiral galaxies

Abstract

We present the radial Tully-Fisher relations (hereafter TFR) for a set of 36 dwarf spirals. The Tully-Fisher relation has been widely studied in the past for normal spirals, we here investigate it for galaxies which are very dim and dark matter dominated. We find that the magnitudes in K band are not good priors of the mass of these objects and that the slope of the TFR is increasing with respect to the radius. Substituting the magnitude by the dynamical stellar disc mass and then adding another parameter, the compactness helps us to reduce the scatter of the TFR. All the relations that we found are a suitable approach to probe dark matter in these dark matter dominated objects and it confirms the Universal Rotation Curve paradigm for dwarf discs pioneered by Karukes & Salucci(2016).