| This is a two part thesis. In the first third I detail the Echellette Spectrograph and Imager (ESI), a moderate resolution spectrograph developed by Lick Observatory for use at the Keck II telescope. In the last two thirds I discuss the spectroscopy of 14 QSO host galaxies, with detailed analysis of four objects that are representative of the larger sample. The spectra are obtained both with the Low Resolution Imaging Spectrometer and with ESI. I first discuss the observed properties of the larger sample e.g. emission-line strengths, surface brightnesses and luminosities and compare individual cases with information in the literature. Secondly, I discuss the derived properties, systemic velocity shifts, velocity dispersions, and stellar population components. In the spectra of 3C 323.1, PG 1444 +407,4C 31.63 and PKS 2349 -014, I apply the tools of population synthesis to explore the relative contribution of the individual spectral components to the observed luminosity. In particular, I show evidence for four principle components in most of the spectra: (1) emission-line gas; (2) Old stellar population, in which star formation has not occurred for of order 1 Gyr.; (3) Young stellar component showing evidence for ongoing or recent star formation; (4) Scattered nuclear-light component. We conclude that objects showing only old stellar population components are in the distinct minority in our sample. Lastly, I explore the kinematics of the gas associated with three of the objects. The emission-line gas shows a wide distribution in gas morphology, uncorrelated with the continuum morphology. Most objects also show several velocity components in the gas with dispersions up to 1000 km/sec. |
