Theory and modeling of gamma-ray pulsars

Newborn neutron stars from supernovae explosions radiate brightly in {dollar}gamma{dollar} rays, outshining all other objects in the Galaxy. The {dollar}gamma{dollar} rays are emitted in a beam, and a flash of emission is observed at every rotation of the star; hence these objects are called {dollar}gamma{dollar}-ray pulsars. A great amount of energy is radiated in this form ({dollar}sim{dollar} 10{dollar}sp{lcub}35{rcub}{dollar} erg/s), originating from the kinetic energy associated with the rapid ({dollar}sim{dollar}100 ms) rotation of the neutron star. As this energy is sapped and converted to {dollar}gamma{dollar} rays, the star slows down, to {dollar}sim{dollar}1 s period after a million years. At this time, the {dollar}gamma{dollar}-ray emission suddenly stops.; Driven by the explosion in number and quality of {dollar}gamma{dollar}-ray pulsar observations with the launch of the EGRET instrument aboard the Compton Gamma Ray Observatory in 1991, we have revisited the theory and modeling of {dollar}gamma{dollar}-ray pulsars. We adopt a particular point of view in our efforts, refraining from detailed computations of the radiation spectra and looking instead to establish a number of important features of the magnetosphere and emission zones. Building on previous efforts, I have developed an outer gap model of the emission geometry and physics which is successful in explaining many of the key features of the observations. In particular the complex light curves find a natural explanation in this model. Several important puzzles remain and are presented as a challenge for future investigations.; If one can successfully model the {dollar}gamma{dollar}-ray emissions, {dollar}gamma{dollar}-ray pulsars as a group can be used to explore general properties of our Galaxy. Initial applications of this idea are presented. We enlarge the sample of {dollar}gamma{dollar}-ray pulsars by searching for associations of unidentified Galactic plane EGRET sources with tracers of massive stars. The characteristics of the candidate identifications are compared to detailed Galactic population syntheses using our pulsar emission model. We find good agreement with model predictions. A constraint is derived on the minimum mass a star must have in order to form a neutron star at its death. The population studies of this thesis make it clear that we do not yet have a consistent picture of supernovae and their offspring.