HI Studies of the Sculptor Group Galaxies. I. Membership and M/L of the Group

We examine the controversy over the Sculptor group membership. It is shown that a study of the dynamical properties of the group enables us to eliminate nonmember galaxies and to get a better estimate for the mass of this system. The inferred mass gives a mass-to-light ratio of (M/L_B_)_dyn_, = 83 +/- 10 M_sun_/L_sun_, which is consistent with the mean msss-to-light ratio estimated for other groups. The present analysis disfavors previous determinations as high as (M/L_B_)_dyn_, ~500 for the Sculptor group.