A SINFONI Integral Field Spectroscopy Survey for Galaxy Counterparts to Damped Lyman-alpha Systems - IV. Masses and Gas Flows

Abstract: The circumgalactic medium (CGM) of typical galaxies is crucial to our understanding of the cycling of gas into, through and out of galaxies. One way to probe the CGM is to study gas around galaxies detected via the absorption lines they produce in the spectra of background quasars. Here, we present medium resolution and new ~0.4-arcsec resolution (~3 kpc at z~1) 3D observations with VLT/SINFONI of galaxies responsible for high-N(HI) quasar absorbers. These data allow to determine in details the kinematics of the objects: the four z~1 objects are found to be rotation-supported as expected from inclined discs, while the fifth z~2 system is dispersion-dominated. Two of the systems show sign of interactions and merging. In addition, we use several indicators (star formation per unit area, a comparison of emission and absorption kinematics, arguments based on the inclination and the orientation of the absorber to the quasar line-of-sight and the distribution of metals) to determine the direction of the gas flows in and out of these galaxies. In some cases, our observations are consistent with the gas seen in absorption being due to material co-rotating with their halos. In the case of absorbing-galaxies towards Q1009-0026 and Q2222-0946, these indicators point toward the presence of an outflow traced in absorption.