Towards a self-consistent modelling of pulsar magnetospheres

The numerical modelling of the general case of an obligue rotator is a very complicated time-dependent three-dimensional problem and in its full extent probably outside the capacity of present-day computers. A considerable simplification occurs if one can assume that the essential effects may be understood by modelling the magnetosphere of an aligned rotator (where the rotation axis is parallel to the magnetic axis of the neutron star). This assumption is only reasonable for small obliguenses, since by this approach all electromagnetic wave effects are not taken into account. An advantage, however, is that unipolar induction, which should be responsible for populsting the magnetosphere with charged particles pulled out from the neutron star surface via field emission, can be studied purity

Generation of relativistic particles in pulsar magnetospheres

The problem - fundamental for the physics of pulsars - of determining the global structure of the magnetosphere in a self-consistent way has not yet been solved satisfactorily. We report on some progress in this direction, which we have achieved by studying the trajectories of individual charged particles in the electromagnetic vacuum fields of an aligned rotator

Effects of radiation damping on particle motion in pulsar vacuum fields

The effects of radiation reaction on the motion of charged particles are studied in strong electric and magnetic fields with special attention to the vacuum near-field region of an oblique rotator. For strong radiation damping a local velocity field is derived from the Lorentz-Dirac equation, which efficiently describes the motion of electrons and positrons in the whole range of typical pulsar parameters. The velocity field makes it possible to define regions in the inner magnetosphere, where particle trapping occurs due to the radiation losses. By numerical integration of particle trajectories from the pulsar surface, regions around the magnetic poles are found which are defined by particle emission into the wave zone. The shapes of the escape regions on the pulsar surface are determined to a considerable extent by the presence of the accumulation regions

Towards a self-consistent modelling of pulsar magnetospheres

The numerical modelling of the general case of an oblique rotator is a very complicated time-dependent 3-dimensional problem and in its full extent probably outside the capicity of present.day computers. A considerable simplification occurs if one can assume that the essential effects may be understood by modelling the magnetosphere of an aligned rotator (where the rotation axis is parallel to the magnetic axis of the neutron star). This assumption is only reasonable for small obliqueness, since by this approach all electromagnetic wave effects are not taken into account

Self-consistent modelling of pulsar magnetospheres

We report on some progress that we have achieved by numerically modelling the magnetosphere of an aligned rotator where the rotation axis is parallel to the magnetic axis of the neutron star. Here, the unipolar induction, which should be responsible for populating the magnetosphere with charged particles pulled out from the neutron star surface via field emission can be studied in purity, whereas electromagnetic wave effects are neglected

Self-consistent numerical modelling of pulsar magnetospheres

The magnetosphere of a rapidly rotating, strongly magnetized neutron star with aligned magnetic and rotational axes (parallel rotator) is modelled numerically. Including the radiation of the particles accelerated to relativistic energies as an efficient damping mechanism, we obtain a quasi-stationary self-consistent solution to this classical problem. The numerical simulation,which was started from the well-known vacuum solution, yields a global magnetospheric structure that can be characterized by two regions of oppositely charged particles, which eventually produce a relativistic pulsar wind, separated by a vacuum gap of considerable extent

Particle motion in pulsar magnetospheres

This report discusses some new results we found in studying the trajectories of single charged particles in the vacuum magnetosphere of a pulsar using the oblique rotator model. We believe that investigations of individual particles in the vicinity of the star can be useful for a better understanding of some fundamental problems of pulsar physics, e.g. the global structure of the magnetosphere or the pulsar radiation

Interactive control of biomechanical animation

Physics-based animation can be generated by performing a complete dynamical simulation of multibody systems. This leads to the solving of a complex system of differential equations in which biomechanical results for the physics of impacts are incorporated. Motion control is achieved by interactively modifying the internal torques. Realtime response requires the distribution of the workload of the computation between a high-speed compute server and the graphics workstation by means of a remote-procedure call mechanism

Kinematics and dynamics for computer animation

This tutorial will focus on the physical principles of kinematics and dynamics. After explaining the basic equations for point masses and rigid bodies a new approach for the dynamic simulation of multi-linked models with wobbling mass is presented, which has led to new insight in the field of biomechanics, but which has not been used in computer animation so far