Imaging and Spectroscopy of Galaxies Associated with Two z ~ 0.7 Damped Lyα Absorption Systems
We have identified galaxies near two quasars that are at the redshift of damped Lyα (DLA) systems in the UV spectra of the quasars. Both galaxies are actively forming stars. One galaxy has a luminosity close to the break in the local galaxy luminosity function, L*; the other is significantly fainter than L* and appears to be interacting with a nearby companion. Despite the strong selection effects favoring spectroscopic identification of the most luminous DLA galaxies, many of the spectroscopically identified DLA galaxies in the literature are sub-L*, suggesting that the majority of the DLA population is probably sub-L*, in contrast to Mg II absorbers at similar redshifts, whose mean luminosity is close to L*.
© 2003 The American Astronomical Society. Received 2003 March 10; accepted 2003 August 8. We thank an anonymous referee for helpful comments. This work was partly carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration (NASA), and partly under the auspices of the US Department of Energy, National Nuclear Security Administration by the University of California, Lawrence Livermore National Laboratory, under contract No. W-7405-Eng-48, with additional support from NASA grant HST-GO-09051.01-A and NSF grant AST 00-98355 (University of California, Davis). Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA. The observatory was made possible by the generous financial support of the W.M. Keck Foundation. The authors wish to acknowledge the significant cultural role and reverence that the summit of Mauna Kea has always had within the indigenous Hawaiian community. This research has also made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA.
Published - Lacy_2003_AJ_126_2230.pdf