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Subject: search.filters.subject.530Institute: search.filters.UBSInstitut.Sonstige EinrichtungEnd date: 1989Author: search.filters.author.Herold, Heinz

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Now showing 1 - 8 of 8
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    Self-consistent modelling of pulsar magnetospheres
    (1989) Herold, Heinz; Ertl, Thomas; Finkbeiner, Bernd; Ruder, Hanns
    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 selfconsistent 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.
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    Particle motion in pulsar magnetospheres
    (1987) Finkbeiner, Bernd; Ertl, Thomas; Herold, Heinz; Ruder, Hanns
    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.
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    Generation of relativistic particles in pulsar magnetospheres
    (1985) Herold, Heinz; Ertl, Thomas; Ruder, Hanns
    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.
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    Effects of radiation damping on particle motion in pulsar vacuum fields
    (1989) Finkbeiner, Bernd; Herold, Heinz; Ertl, Thomas; Ruder, Hanns
    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.
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    Towards a self-consistent modelling of pulsar magnetospheres
    (1986) Herold, Heinz; Ertl, Thomas; Ruder, Hanns
    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.
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    Line-of-sight integration: a powerful tool for visualization of three-dimensional scalar fields
    (1989) Ruder, Hanns; Ertl, Thomas; Geyer, Florian; Herold, Heinz; Kraus, Ute
    An easy conceivable but very powerful method for the visualization of three-dimensional scalar fields is described. The way this method works is illustrated by some examples and the computed pictures are compared with the results of other methods of representation.
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    Visualization in astrophysics
    (1989) Ertl, Thomas; Geyer, Florian; Herold, Heinz; Kraus, Ute; Niemeier, Roland; Nollert, Hans-Peter; Rebetzky, Andreas; Ruder, Hanns; Zeller, Gudrun
    This paper reports on progress we have made in modelling cosmic X·ray sources on supercomputers. The results we present are meant to serve as an example for the fact that sophisticated visualization techniques play a crucial role in scientific computing. Among the graphical methods we demonstrate, raytracing in curved space-time and a physically motivated 3D-volume rendering algorithm might be of interest to the graphics community in general.
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    Self-consistent modelling of pulsar magnetospheres
    (1987) Ertl, Thomas; Herold, Heinz; Finkbeiner, Bernd; Ruder, Hanns
    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.