MSA-3D: Rotation Curves and Dark Matter Fractions at z 0.5-1.7 with JWST/NIRSpec

We present rotation curves and inner mass distributions for 30 star-forming galaxies at 0.5<z<1.7, observed with JWST/NIRSpec as part of the MSA-3D Cycle 1 survey. Combining spatially resolved ionised-gas kinematics with JWST/NIRCam imaging, we constrain baryonic and dark matter contributions through forward dynamical modelling for galaxies extending down to stellar masses of about10 9M. For the 23 galaxies in our primary statistical sample, we find predominantly rotationally supported disks with intrinsic dispersions sigma 0 about31-65 km s-1 and a wide range of dark matter fractions, f DM(R e) about0.1-0.9, with a median of 0.63 and substantial galaxy-to-galaxy scatter of about0.2 dex. These results are supported by a complementary consistency check using stellar mass maps and SFR-derived gas profiles. Among the 19 galaxies reaching 2R e, we identify six rising, six flat, and seven falling rotation curves. These classes define an observed ordering from rotationally dominated, dark-matter-rich disks (V rot/sigma 0 about4, f DM 0.7) to more dispersion-supported systems with centrally concentrated baryonic mass distributions (V rot/sigma 0 about2, f DM 0.55). The stellar Tully-Fisher relation lies close to the local relation evolved under the adopted self-similar CDM scaling. A simplified seeing-degradation test shifts the inferred normalisation by 0.2 dex at fixed V c, suggesting that spatial resolution contributes to, but does not fully explain, differences among high-redshift Tully-Fisher measurements. Overall, MSA-3D provides a high-resolution extension of previous surveys toward lower stellar masses, spanning 9.0 < (M/M) < 11.2, and reinforces that star-forming disks near z about1 span a broad range of dynamical states and inner mass distributions.