SINFONI Integral Field Spectroscopy ofz∼ 2 UV‐selected Galaxies: Rotation Curves and Dynamical Evolution

We present 0.5" resolution near-IR integral field spectroscopy of the Ha lineemission of 14 z~2 UV-selected BM/BX galaxies obtained with SINFONI at ESO/VLT.The mean Ha half-light radius r_1/2 is about 4kpc and line emission is detectedover > ~20kpc in several sources. In 9 sources, we detect spatially-resolvedvelocity gradients, from 40 to 410 km/s over ~10kpc. The observed kinematics ofthe larger systems are consistent with orbital motions. Four galaxies are welldescribed by rotating disks with clumpy morphologies and we extract rotationcurves out to radii > ~10kpc. One or two galaxies exhibit signatures moreconsistent with mergers. Analyzing all 14 galaxies in the framework of rotatingdisks, we infer mean inclination- and beam-corrected maximum circularvelocities v_c of 180+-90 km/s and dynamical masses of (0.5-25)x10^10 Msunwithin r_1/2. On average, the dynamical masses are consistent with photometricstellar masses assuming a Chabrier/Kroupa IMF but too small for a 0.1-100 MsunSalpeter IMF. The specific angular momenta of our BM/BX galaxies are similar tothose of local late-type galaxies. The specific angular momenta of theirbaryons are comparable to those of their dark matter halos. Extrapolating fromthe average v_c at 10kpc, the virial mass of the typical halo of a galaxy inour sample is 10^(11.7+-0.5) Msun. Kinematic modeling of the 3 best casesimplies a ratio of v_c to local velocity dispersion of order 2-4 andaccordingly a large geometric thickness. We argue that this suggests a massaccretion (alternatively, gas exhaustion) timescale of ~500Myr. We also arguethat if our BM/BX galaxies were initially gas rich, their clumpy disks willsubsequently lose their angular momentum and form compact bulges on a timescaleof ~1 Gyr. [ABRIDGED]