This thesis is a comprehensive work that addresses many of the open questions currently being discusssed in the very-high-energy (VHE) gamma-ray community. It presents a detailed description of the MAGIC telescope together with a glimpse of the future Cherenkov Telescope Array (CTA). One section is devoted to the design, development and characterization of trigger systems for current and future imaging atmospheric Cherenkov telescopes. The book also features a state-of-the-art description of pulsar wind nebula (PWN) systems, the study of the multi-TeV spectrum of the Crab nebula, as well as the discovery of VHE gamma rays at the multiwavelength PWN 3C 58, which were sought at these wavelengths for more than twenty years. It also includes the contextualization of this discovery amongst the current population of VHE gamma-ray PWNe. Cataclysmic variable stars represent a new source of gamma ray energies, and are also addressed here. In closing, the thesis reports on the systematic search for VHE gamma-ray emissions of AE Aquarii in a multiwavelength context and the search for VHE gamma-ray variability of novae during outbursts at different wavelengths.

This book reports on the extraordinary observation of TeV gamma rays from the Crab Pulsar, the most energetic light ever detected from this type of object. It presents detailed information on the painstaking analysis of the unprecedentedly large dataset from the MAGIC telescopes, and comprehensively discusses the implications of pulsed TeV gamma rays for state-of-the-art pulsar emission models. Using these results, the book subsequently explores new testing methodologies for Lorentz Invariance Violation, in terms of a wavelength-dependent speed of light. The book also covers an updated search for Very-High-Energy (VHE), >100 GeV, emissions from millisecond pulsars using the Large Area Telescope on board the Fermi satellite, as well as a study on the promising Pulsar Wind Nebula candidate PSR J0631. The observation of VHE gamma rays is essential to studying the non-thermal sources of radiation in our Universe. Rotating neutron stars, also known as pulsars, are an extreme source class known to emit VHE gamma rays. However, to date only two pulsars have been detected with emissions above 100 GeV, and our understanding of their emission mechanism is still lacking.

The aim of the inaugural meeting of the Sant Cugat Forum on Astrophysics was to address, in a global context, the current understanding of and challenges in high-energy emissions from isolated and non-isolated neutron stars, and to confront the theoretical picture with observations of both the Fermi satellite and the currently operating ground-based Cherenkov telescopes. Participants have also discussed the prospects for possible observations with planned instruments across the multi-wavelength spectrum (e.g. SKA, LOFAR, E-VLT, IXO, CTA) and how they will impact our theoretical understanding of these systems. In keeping with the goals of the Forum, this book not only represents the proceedings of the meeting, but also a reflection on the state-of-the-art in the topic.

This book reports on the extraordinary observation of TeV gamma rays from the Crab Pulsar, the most energetic light ever detected from this type of object. It presents detailed information on the painstaking analysis of the unprecedentedly large dataset from the MAGIC telescopes, and comprehensively discusses the implications of pulsed TeV gamma rays for state-of-the-art pulsar emission models. Using these results, the book subsequently explores new testing methodologies for Lorentz Invariance Violation, in terms of a wavelength-dependent speed of light. The book also covers an updated search for Very-High-Energy (VHE), >100 GeV, emissions from millisecond pulsars using the Large Area Telescope on board the Fermi satellite, as well as a study on the promising Pulsar Wind Nebula candidate PSR J0631. The observation of VHE gamma rays is essential to studying the non-thermal sources of radiation in our Universe. Rotating neutron stars, also known as pulsars, are an extreme source class known to emit VHE gamma rays. However, to date only two pulsars have been detected with emissions above 100 GeV, and our understanding of their emission mechanism is still lacking.

The aim of this Thesis is to study the development of pulsar wind nebulae in the TeV regime and in doing so uncover more sources which have as yet not been observed at these wavelengths. It is found that the extent of pulsar wind nebula in the TeV gamma-ray increases with its age while no developmental relationship is seen concerning the luminosity or spectral index of the nebulae when observed in the TeV gamma-ray regime due to uncertainties in the measurements available. TeV gamma-ray upper limits are calculated for several nebulae observed in the X-ray regime allowing the strength of their magnetic fields to be constrained but only one new source, which was previously confused with its companion, was discovered, the Eel Nebula. Predictions of the fluxes of many of the sources for which upper limits are derived in this work have been calculated from observations of their emission in X-rays and some of these sources should be uncovered with the next generation CTA instrument.

Energetic particles streaming out from rapidly spinning neutron stars radiate across the electromagnetic spectrum, creating a pulsar wind nebula (PWN). Many PWNe are spatially resolved in the radio, X-ray, and even gamma-ray wavebands, and thereby provide an excellent laboratory to study not only pulsar winds and dynamics, but also shock processes, magnetic field evolution, and particle transport. Single-zone spectral energy distribution (SED) models have long been used to study the global properties of PWNe, but to fully take advantage of high spatial resolution data one must move beyond these simple models. Supported by multiple X-ray PWN observations, we describe multi-zone time-dependent SED model fitting, with particular emphasis on the spatial variations within nebulae. The SED model constrains the wind velocity profile, magnetic field profile, age and spin-down history of the central pulsar, and the PWN injection spectrum. These constraints are of great value to the study of the gamma-ray pulsar population, and to investigations of particle acceleration and the cosmic ray spectrum. The large size of many PWNe in the very high energy gamma-ray (TeV) regime is indicative of significant particle transport over the pulsar lifetime, and in the case study of HESS J1825-137 we find that rapid diffusion of high energy particles is required to match the multi-wavelength data.