Adaptive Optics Imaging of Low-redshift Damped Lyman-alpha Quasar Absorbers


Abstract in English

We have carried out a high angular resolution near-infrared imaging study of the fields of 6 quasars with 7 strong absorption line systems at z < 0.5, using the Hokupaa adaptive optics system and the QUIRC near-infrared camera on the Gemini-North telescope. These absorption systems include 4 classical damped Lyman-alpha absorbers (DLAs), 2 sub-DLAs, and one Lyman-limit system. Images were obtained in the H or K filters with FWHM between 0.2-0.5 with the goal of detecting the absorbing galaxies and identifying their morphologies. Features are seen at projected separations of 0.5-16.0 from the quasars and all of the fields show features at less than 2 separation. We find candidate absorbers in all of the seven systems. With the assumption that some of these are associated with the absorbers, the absorbers are low luminosity < 0.1 L*_H or L*_K; we do not find any large bright candidate absorbers in any of our fields. Some fields show compact features that are too faint for quantitative morphology, but could arise in dwarf galaxies.

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