A SINFONI integral field spectroscopy survey for galaxy counterparts to damped Lyman α systems - III. Three additional detections

Abstract

We report three additional Spectrograph for Integral Field Observations in the Near Infrared (SINFONI) detections of Hα emission line from quasar absorbers, two of which are new identifications. These were targeted among a sample of systems with and metallicities measured from high-resolution spectroscopy. The detected galaxies are at impact parameters ranging from 6 to 12kpc from the quasar's line of sight. We derive star formation rates (SFRs) of a few M ⊙yr -1 for the two absorbers at z abs∼ 1 and SFR = 17M ⊙yr -1 for the damped Lyman α system (DLA) at z abs∼ 2. These three detections are found among a sample of 16 DLAs and sub-DLAs (five at z abs∼ 1 and seven at z abs∼ 2). For the remaining undetected galaxies, we derive flux limits corresponding to SFR < 0.1-11.0M ⊙yr -1 depending on redshift of the absorber and depth of the data. When combined with previous results from our survey for galaxy counterparts to Hi-selected absorbers, we find a higher probability of detecting systems with higher metallicity as traced by dust-free [Zn/H] metallicity. We also report a higher detection rate with SINFONI for host galaxies at z abs∼ 1 than for systems at z abs∼ 2. Using the [Nii]/Hα ratio, we can thus compare absorption and emission metallicities in the same high-redshift objects, more than doubling the number of systems for which such measures are possible. © 2011 The Authors Monthly Notices of the Royal Astronomical Society © 2011 RAS.