Imaging of BL Lac objects
The investigation of the host galaxies of BL Lac objects (BL Lacs) is a promising new field made practical in recent years by advances in detector technology and improved telescope siting. By better understanding the nature of these host galaxies we can test the standard beaming and lensing models for BL Lacs. This thesis describes the techniques that we have developed for studying the host galaxies of BL Lac objects, and presents the results of a survey of BL Lac host galaxies that we have undertaken with the 4.2m William Herschel Telescope. This survey successfully resolved many new host galaxies, determined the morphology of three BL Lac host galaxies for the first time, and confirmed the morphology of an additional three objects. One BL Lac object, PKS1413+135, displayed a number of surprising properties, and was consequently studied in greater detail at multiple wavelengths. These observations are also presented in this thesis. We conclude with a description of Monte-Carlo simulations that we have undertaken in order to better determine the uncertainty in the results from our survey, and to assess the promise of future telescope/instrumentation combinations for host galaxy imaging.