2013AJ....146..121H

In this first paper, we combine a structural analysis of the near-IR surface brightness profiles and [N II] rotation curves for the galaxies in the pair NGC 5953/5954 to model the mass distribution in each member by using two independent axisymmetric analytical mass models: (1) a standard model given by the sum of a spherical bulge with the Sérsic law, a stellar exponential disk, and a cold dark matter halo represented by the improved fitting formula of Navarro et al.; and (2) a simple model given by the sum of a spherical bulge, a finite oblate spheroid representing the disk, and a spherical dark halo, all three mass components with simple density laws. In our surface brightness fits, a central luminous source is considered in both galaxies. We obtained K-band M/L ratios, Υ_D, Υ_B, for the disks and bulges, and total masses for each mass component in both galaxies. With the standard model we find in NGC 5953, (Υ_D,Υ_B) = (0.29_–0.29⁺¹, 0.37±0.03) M_☉/L_☉, and in NGC 5954, (Υ_ D_,ΥB_) = (0.88±0.18, 0.21±0.09) M_☉/L_☉. Corresponding values found with the simple model are (Υ_D,Υ_ B_) = (1.41±0.15, 0.29±0.04) M_☉/L_☉ and (Υ_ D_,ΥB_) = (0.51±0.05, 0.52_–0.12^+0.23) M_☉/L_☉. Our M/L estimates are compared with predictions from other methods in the literature, finding reasonable agreement. The dark halos estimated using the simple model have a small mass, of the order of 10⁷ M_☉, within the maximum distance in the rotation velocity data.