Dark matter in early-type spiral galaxies: the case of NGC 2179 and of NGC2775

We present the stellar and ionized-gas velocity curves and velocity-dispers ion profiles along the major axis for six early-type spiral galaxies. Two of these galaxies, namely NGC 2179 and NGC 2775, are particularly suite d for the study of dark matter halos. Using their luminosity profiles and m odeling their stellar and gaseous kinematics, we derive the mass contributi ons of the luminous and the dark matter to the total potential. In NGC 2179 we find that the data (measured out to about the optical radius R-opt) una mbiguously require the presence of a massive dark halo. For the brighter an d bigger object NGC 2775, we can rule out a significant halo contribution a t radii R less than or similar to 0.6 R-opt. Although preliminary, these re sults agree with the familiar mass distribution trend known for late-type s pirals of comparable mass.