Sinfoni integral field spectroscopy of z ∼ 2 UV-selected galaxies:: Rotation curves and dynamical evolution

We present similar to 0".5 resolution near-infrared integral field spectroscopy of the H alpha line emission of 14 z similar to 2 UV-selected BM/BX galaxies, obtained with SINFONI at the ESO Very Large Telescope. The average H alpha half-light radius is r(1/2) approximate to 4h(70)(-1) kpc, and line emission is detected over greater than or similar to 20h(70)(-1) kpc in several sources. In nine galaxies, we detect spatially resolved velocity gradients, from 40 to 410 km s(-1) over similar to 10 h(70)(-1) kpc. The kinematics of the larger systems are generally consistent with orbital motions. Four galaxies are well described by rotating clumpy disks, and we extracted rotation curves out to radii greater than or similar to 10 h(70)(-1) kpc. One or two galaxies exhibit signatures more consistent with mergers. Analyzing all 14 galaxies in the framework of rotating disks, we infer mean inclination- and beam-corrected maximum circular velocities of v(c) similar to 180 +/- 90 km s(-1) and dynamical masses from similar to 0.5 to 25 x 10(10) h(70)(-1) M-circle dot within r(1/2). The specific angular momenta of our BM/BX galaxies are similar to those of local late-type galaxies. Moreover, the specific angular momenta of their baryons are comparable to those of their dark matter halos. Extrapolating from the average vc at 10 h(70)(-1) kpc, the virial mass of the typical halo of a galaxy in our sample is 10(11:7 +/- 0.5) h(70)(-1) M-circle dot. Kinematic modeling of the three best cases implies a ratio of v(c) to local velocity dispersion v(c)/sigma similar to 2-4 and, accordingly, a large geometric thickness. We argue that this suggests a mass accretion (alternatively, gas exhaustion) timescale of similar to 500 Myr. We also argue that if our BM/BX galaxies were initially gas-rich, their clumpy disks would subsequently lose their angular momentum and form compact bulges on a timescale of similar to 1 Gyr.