Electric Field Screening with Back-Flow at Pulsar Polar Cap
arXiv:1607.02202 · doi:10.3847/0004-637X/829/1/12
Abstract
Recent -ray observations suggest that the particle acceleration occurs at the outer region of the pulsar magnetosphere. The magnetic field lines in the outer acceleration region (OAR) are connected to the neutron star surface (NSS). If copious electron--positron pairs are produced near the NSS, such pairs flow into the OAR and screen the electric field there. To activate the OAR, the electromagnetic cascade due to the electric field near the NSS should be suppressed. However, since a return current is expected along the field lines through the OAR, the outflow extracted from the NSS alone cannot screen the electric field just above the NSS. In this paper, we analytically and numerically study the electric-field screening at the NSS taking into account the effects of the back-flowing particles from the OAR. In certain limited cases, the electric field is screened without significant pair cascade if only ultrarelativistic particles () flow back to the NSS. On the other hand, if electron--positron pairs with a significant number density and mildly relativistic temperature, expected to distribute in a wide region of the magnetosphere, flow back to the NSS, these particles adjust the current and charge densities, so that the electric field can be screened without pair cascade. We obtain the condition for the number density of particles to screen the electric field at the NSS. We also find that in ion-extracted case from the NSS, bunches of particles are ejected to the outer region quasi-periodically, which is a possible mechanism of observed radio emission.
arXiv comment15 pages, 13 figures, 1 table. Accepted for publication in Astrophysical Journal
References in corpus (40)
- Corona of Magnetars
- Gamma Ray Pulsars: Emission from Extended Polar Cap Cascades
- Modeling of Gamma-Ray Pulsar Light Curves with Force-Free Magnetic Field
- Current Flow and Pair Creation at Low Altitude in Rotation Powered Pulsars' Force-Free Magnetospheres: Space-Charge Limited Flow
- 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
- Ab-initio pulsar magnetosphere: three-dimensional particle-in-cell simulations of oblique pulsars
- Modeling high-energy pulsar lightcurves from first principles
- Particle acceleration in axisymmetric pulsar current sheets
- Electrodynamics of axisymmetric pulsar magnetosphere with electron-positron discharge: a numerical experiment
- Ab-initio pulsar magnetosphere: three-dimensional particle-in-cell simulations of axisymmetric pulsars
- On the polar cap cascade pair multiplicity of young pulsars
- Toward a Realistic Pulsar Magnetosphere
- Fermi LAT Observations of the Vela Pulsar
- Gamma-Ray Emission in Dissipative Pulsar Magnetospheres: From Theory to Fermi Observations
- Pulsar polarisation below 200 MHz: Average profiles and propagation effects
- Pulsed radiation from neutron star winds
- X-ray emission from the old pulsar B0950+08
- Large-Amplitude, Pair-Creating Oscillations in Pulsar and Black Hole Magnetospheres
- Polar-cap accelerator and radio emission from pulsars
- Ab-initio pulsar magnetosphere: the role of general relativity
- Radio efficiency of pulsars
- Particle Accelerator in Pulsar Magnetospheres: Super Goldreich-Julian Current with Ion Emission from the Neutron Star Surface
- A two-dimensional electrodynamical outer gap model for gamma-ray pulsars: Gamma-ray spectrum
- Dissipation, Energy Transfer, and Spindown Luminosity in 2.5D PIC Simulations of the Pulsar Magnetosphere
- Testing dissipative magnetosphere model light curves and spectra with FERMI pulsars
- Particle Acceleration and Non-Thermal Emission in Pulsar Outer Magnetospheric Gap
- Fermi-LAT Detection of Pulsed Gamma-rays Above 50 GeV from the Vela Pulsar
- On the pulse-width statistics in radio pulsars. II. Importance of the core profile components
- Three-dimensional non-vacuum pulsar outer-gap model: Localized acceleration electric field in the higher altitudes
- A Particle Simulation for the Pulsar Magnetosphere: Relationship of Polar Cap, Slot Gap, and Outer Gap
- Probing gamma-ray emissions of Fermi-LAT pulsars with a non-stationary outer gap model
- A Particle Simulation for the Axisymmetric Pulsar Magnetosphere: II. the case of dipole field
- A Particle Simulation for the Global Pulsar Magnetosphere: the Pulsar Wind linked to the Outer Gaps
- Mechanism of the X-ray and Soft Gamma-ray Emissions from High Magnetic Field Pulsar: PSR B1509-58
- Adjustment of the electric charge and current in pulsar magnetospheres
- Dead zone in the polar-cap accelerator of pulsars
- Nuclear physics of reverse electron flow at pulsar polar caps
- Ion-proton pulsars
- Multi-wavelength emission region of gamma-ray emitting pulsars
- Full simulation of the open field lines above pulsar's polar cap - Part I
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