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Related papers: Charge densities above pulsar polar caps

200 papers

We present the magnetic and electric field structures as well as the currents and charge densities of pulsar magnetospheres which do not obey the ideal condition, ${\bf E \cdot B =0}$. Since the acceleration of particles and the production…

Solar and Stellar Astrophysics · Physics 2015-05-30 Constantinos Kalapotharakos , Demosthenes Kazanas , Alice Harding , Ioannis Contopoulos

We present numerical simulations of electron-positron pair cascades in the magnetospheres of magnetic neutron stars for a wide range of surface fields (B_p = 10^{12}--10^{15} G), rotation periods (0.1--10 s), and field geometries. This has…

High Energy Astrophysical Phenomena · Physics 2012-07-31 Zach Medin , Dong Lai

There is good evidence that electron-positron pair formation is not present in that section of the pulsar open magnetosphere which is the source of coherent radio emission, but the possibility of two-photon pair creation in an outer gap…

High Energy Astrophysical Phenomena · Physics 2017-03-29 P B Jones

The magnetosphere of strongly magnetized neutron stars, such as magnetars, can sustain large electric currents. The charged particles return to the surface with large Lorentz factors, producing a particle bombardment. We investigate the…

High Energy Astrophysical Phenomena · Physics 2018-12-12 Denis Gonzalez-Caniulef , Silvia Zane , Roberto Turolla , Kinwah Wu

The emission of $\nu\bar\nu$ pairs off electrons in a polarized ultra-intense electromagnetic (e.g.\ laser) wave field is analyzed. We elaborate on the significance of non-linear electrodynamics effects (i.e., multi-photon processes) and…

High Energy Physics - Phenomenology · Physics 2011-03-22 A. I. Titov , B. Kampfer , H. Takabe , A. Hosaka

A recent phenomenological study of radio emission from normal and millisecond pulsars by Karastergiou et al has lead these authors to state that they are unable to exclude a common physics process as the source although the rotation periods…

High Energy Astrophysical Phenomena · Physics 2024-11-28 P B Jones

We investigate a stationary pair production cascade in the outer magnetosphere of a spinning neutron star. The charge depletion due to global flows of charged particles, causes a large electric field along the magnetic field lines.…

Astrophysics · Physics 2008-11-26 Kouichi Hirotani , Alice K. Harding , Shinpei Shibata

We calculate numerically the emissivity and surface flux of electron-electron bremsstrahlung radiation from the surface of a bare quark star. The restricted electronic phase space due to the presence of an effective photon mass results in a…

High Energy Astrophysical Phenomena · Physics 2010-01-07 Jean-François Caron , Ariel R. Zhitnitsky

The motion of electrons and positrons in the vacuum magnetosphere of a neutron star with a surface magnetic field of B~10^12 G is considered. Particles created in the magnetosphere or falling into it from outside are virtually…

High Energy Astrophysical Phenomena · Physics 2010-12-17 Ya. N. Istomin , D. N. Sob'yanin

Pulsar "standard model", that considers a pulsar as a rotating magnetized conducting sphere surrounded by plasma, is generalized to the case of oscillating star. We developed an algorithm for calculation of the Goldreich-Julian charge…

Astrophysics · Physics 2008-11-26 Andrey N. Timokhin

Magnetic fields inside and around neutron stars are at the heart of pulsar magnetospheric activity. Strong magnetic fields are responsible for quantum effects, an essential ingredient to produce leptonic pairs and the subsequent broadband…

High Energy Astrophysical Phenomena · Physics 2017-11-08 Jérôme Pétri

The subpulse drifting phenomenon in pulsar radio emission is considered within the partially screened inner gap model, in which the sub-Goldreich-Julian thermionic flow of iron ions or electrons coexists with the spark-associated…

Astrophysics · Physics 2008-11-26 Janusz Gil , George Melikidze , Bing Zhang

We study electron-positron pair production in polar caps of energetic pulsars to determine the maximum multiplicity of pair plasma a pulsar can produce under the most favorable conditions. This paper complements and updates our study of…

High Energy Astrophysical Phenomena · Physics 2019-01-23 A. N. Timokhin , A. K. Harding

Aims. Many recent observations of pulsars and magnetars can be interpreted in terms of neutron stars (NS) with multipole electromagnetic fields. As a first approximation, we investigate the multipole magnetic and electric fields in the…

High Energy Astrophysical Phenomena · Physics 2020-07-07 S. Bonazzola , F. Mottez , J. Heyvaerts

A self-consistent electrodynamics of a particle accelerator in a rotating neutron-star magnetosphere is investigated on the two-dimensional poloidal plane. Solving the Poisson equation for the electrostatic potential together with the…

Astrophysics · Physics 2007-05-23 K. Hirotani

Protons produced in electromagnetic showers formed by the reverse-electron flux are usually the largest component of the time-averaged polar-cap open magnetic flux-line current in neutron stars with positive corotational charge density.…

High Energy Astrophysical Phenomena · Physics 2015-05-14 P B Jones

In Ruderman & Sutherland (RS75) model, the normal neutron stars as pulsars bear a severe problem, namely the binding energy problem that both ions (e.g., ${}_{26}^{56}$Fe) and electrons on normal neutron star surface can be pulled out…

High Energy Astrophysical Phenomena · Physics 2015-05-18 Junwei Yu , Renxin Xu

We continue our investigation of particle acceleration in the pulsar equatorial current sheet (ECS) that began with Contopoulos (2019) and Contopoulos & Stefanou (2019). Our basic premise has been that the charge carriers in the current…

High Energy Astrophysical Phenomena · Physics 2020-01-08 Ioannis Contopoulos , Jerome Petri , Petros Stefanou

We investigate a pair creation cascade in the magnetosphere of a rapidly rotating neutron star. We solve the set of the Poisson equation for the electro-static potential and the Boltzmann equations for electrons, positrons, and gamma-ray…

Astrophysics · Physics 2007-05-23 P. C. Hsu , K. Hirotani , H. K. Chang

A two-dimensional electrodynamical model is used to study particle acceleration in the outer magnetosphere of a pulsar. The charge depletion from the Goldreich-Julian charge density causes a large electric field along the magnetic field…

Astrophysics · Physics 2009-11-13 J. Takata , S. Shibata , K. Hirotani , H. -K. Chang