Astronomy and Astrophysics – Astrophysics – High Energy Astrophysical Phenomena
Scientific paper
2010-06-11
MNRAS, 2010, Vol. 408, pp. 2092-2114
Astronomy and Astrophysics
Astrophysics
High Energy Astrophysical Phenomena
24 pages, 16 figures; MNRAS, in press
Scientific paper
10.1111/j.1365-2966.2010.17286.x
I argue that the problem of electromagnetically driven electron-positron cascades in magnetospheres of neutron stars must be addressed starting from first principles. I describe a general numerical algorithm for doing self-consistent kinetic simulations of electron-positron cascades - wherein particle acceleration, pair creation and screening of the electric field are calculated simultaneously - and apply it to model the Ruderman and Sutherland cascade in one dimension. I find that pair creation is quite regular and quasi-periodic. In each cycle a blob of ultrarelativistic electron-positron plasma is generated, it propagates into the magnetosphere leaving a tail of less relativistic plasma behind, and the next discharge occurs when this mildly relativistic plasma leaves the polar cap. A short burst of pair formation is followed by a longer quiet phase when accelerating electric field is screened and no pairs are produced. Some of freshly injected electron-positrons pairs get trapped in plasma oscillations creating a population of low energy particles. The cascade easily adjusts to the current density required by the pulsar magnetosphere by reversing some of the low energy particles. Each discharge generates a strong coherent superluminal electrostatic wave, which may be relevant for the problem of pulsar radioemission.
No associations
LandOfFree
Time-dependent pair cascades in magnetospheres of neutron stars I. Dynamics of the polar cap cascade with no particle supply from the neutron star surface does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Time-dependent pair cascades in magnetospheres of neutron stars I. Dynamics of the polar cap cascade with no particle supply from the neutron star surface, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Time-dependent pair cascades in magnetospheres of neutron stars I. Dynamics of the polar cap cascade with no particle supply from the neutron star surface will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-644521