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Drift approximation and ideal MHD of cold relativistic winds

Published online by Cambridge University Press:  11 May 2016

Sergey V. Bogovalov*
Affiliation:
National Research Nuclear University (MEPhI), Kashirskoje shosse 31, 115409, Russia
*
Email address for correspondence: svbogovalov@mephi.ru

Abstract

A critical revision of the essential principles of the physics of relativistic flows of cold plasma is given. We prove that the approximation of ideal magnetic hydrodynamics of the cold plasma is equivalent to the drift approximation of motion of charged particles in an electromagnetic field. The equations of magnetohydrodynamics are obtained from equations for the drift motion of the charged particles. The conditions of application of the equations of ideal magnetohydrodynamics are obtained. In the case of the Crab pulsar the violation of the frozen-in condition can happen at a distance that well exceeds the distance to the termination shock. One fluid MHD can be incorrect at the light cylinder provided that the Lorentz factor of the plasma exceeds $10^{4}$ and the curvature radius of the flow line is comparable with the light cylinder. It is shown that the electric currents in the cold plasma are the result of the inertial drift motion of the charged particles in the crossed electric and magnetic fields.

Type
Research Article
Copyright
© Cambridge University Press 2016 

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References

Ahiezer, A. I., Ahiezer, I. A., Polovin, R. V., Sitenko, A. G. & Stepanov, K. N. 1974 Electrodynamics of Plasma (in Russian). Nauka.Google Scholar
Ardavan, H. 1976 Magnetospheric shock discontinuities in pulsars. I. Analysis of the inertial effects at the light cylinder. Astrophys. J. 203, 226232.CrossRefGoogle Scholar
Arons, J. 2004 Theory of pulsar winds. Adv. Space Res. 33, 466474.CrossRefGoogle Scholar
Beskin, V. S., Gurevich, A. V. & Istomin, Ya. N. 1983 The electrodynamics of a pulsar magnetosphere. J. Expl Theor. Phys. 85, 401433.Google Scholar
Beskin, V. S. & Rafikov, R. R. 2000 On the particle acceleration near the light surface of radio pulsars. Mon. Not. R. Astron. Soc. 313, 433444.CrossRefGoogle Scholar
Beskin, V. S., Zakamska, N. L. & Sol, H. 2004 Radiation drag effects on magnetically dominated outflows around compact objects. Mon. Not. R. Astr. Soc. 347, 587600.CrossRefGoogle Scholar
Bogovalov, S. V. 2001 Acceleration and collimation of relativistic plasmas ejected by fast rotators. Astron. Astrophys. 371, 11551168.CrossRefGoogle Scholar
Bogovalov, S. V. 2014 Magnetocentrifugal acceleration of bulk motion of plasma in pulsar magnetosphere. Mon. Not. R. Astron. Soc. 443, 21972203.CrossRefGoogle Scholar
Bogolubov, N. N. & Mitropolsky, Yu. A. 1974 Asymptotic Methods in Theory of Nonlinear Oscillations (in Russian). Nauka.Google Scholar
Chen, A. Y. & Beloborodov, F. M. 2014 Electrodynamics of axisymmetric pulsar magnetosphere with electron–positron discharge: a numerical experiment. Astrophys. J. 795L, 22.Google Scholar
Cheng, K. S., Ho, C. & Ruderman, M. A. 1986 Energetic radiation from rapidly spinning pulsars. I – Outer magnetosphere gaps. II – VELA and Crab. Astrophys. J. 300, 500.Google Scholar
Daugherty, J. K. & Harding, A. K. 1994 Polar CAP models of gamma-ray pulsars: emission from single poles of nearly aligned rotators. Astrophys. J. 429, 325.CrossRefGoogle Scholar
Frank-Kamenetsky, D. A. 1968 Lectures on Plasma Physics (in Russian). Atomizdat.Google Scholar
Goldreich, P. & Julian, W. H. 1969 Pulsar electrodynamics. Astrophys. J. 157, 869.CrossRefGoogle Scholar
Gurevich, A. V. & Istomin, Ya. N. 1985 Electron–positron plasma generation in a pulsar magnetosphere. J. Expl Theor. Phys. 89, 3.Google Scholar
Istomin, Ya. N. & Sob’yanin, D. N. 2011 Absorption of gamma-ray photons in a vacuum neutron star magnetosphere: I. Electron–positron pair production. J. Expl Theor. Phys. 113, 592.Google Scholar
Kennel, C. F. & Coroniti, F. V. 1984 Confinement of the Crab pulsar’s wind by its supernova remnant. Astrophys. J. 283, 694.CrossRefGoogle Scholar
Kirk, J. G., Luybarsky, Yu. & Petri, J. 2009 The theory of pulsar winds and nebulae, in neutron stars and pulsars. Astrophys. Space Sci. Lib. 367, 421450.CrossRefGoogle Scholar
Kocharovsky, V. V., Kocharovsky, Vl. V. & Martyanov, V. Ju. 2010 Self-consistent current sheets and filaments in relativistic collisionless plasma with arbitrary energy distribution of particles. Phys. Rev. Lett. 104, 215002.CrossRefGoogle ScholarPubMed
Koide, S. 2009 Generalized relativistic magnetohydrodynamic equations for pair and electron–ion plasmas. Astrophys. J. 696, 22202233.CrossRefGoogle Scholar
Luybarsky, Yu. 2009 Asymptotic structure of Poynting-dominated jets. Astrophys. J. 697, 15701589.CrossRefGoogle Scholar
Medin, Z. & Lai, D. 2010 Pair cascades in the magnetospheres of strongly magnetized neutron stars. Mon. Not. R. Astron. Soc. 406, 1379.Google Scholar
Melatos, A. & Melrose, D. B. 1996 Energy transport in a rotation-modulated pulsar wind. Mon. Not. R. Astron. Soc. 279, 11681190.CrossRefGoogle Scholar
Michel, F. C. 1969 Relativistic stellar-wind torques. Astrophys. J. 158, 727.CrossRefGoogle Scholar
Morozov, A. I. & Solov’ev, L. S. 1963 Motion of charged particles in electromagnetic fields. In Questions of Plasma Theory. (Voprosy Teorii Plasmy) (ed. Leontovich, M. A.), vol. 2, p. 177.Google Scholar
Polovin, R. V. & Demutskii, V. P. 1990 Fundamentals of Magnetohydrodynamics. Consultants Bureau.Google Scholar
Rees, M. J. & Gunn, J. E. 1974 The origin of the magnetic field and relativistic particles in the Crab Nebula. Mon. Not. R. Astron. Soc. 167, 112.CrossRefGoogle Scholar
Romani, R. W. 1996 Gamma-ray pulsars: radiation processes in the outer magnetosphere. Astrophys. J. 470, 469.CrossRefGoogle Scholar
Sivukhin, D. V. 1963 Drift theory of motion of charged particles in electromagnetic fields. In Questions of Plasma Theory (Voprosy Teorii Plasmy) (ed. Leontovich, M. A.), vol. 1, p. 7. Gosatomizdat.Google Scholar
Tchekhovskoy, A., McKinney, J. C. & Narayan, R. 2008 Simulations of ultrarelativistic magnetodynamic jets from gamma-ray burst engines. Mon. Not. R. Astron. Soc. 388, 551572.CrossRefGoogle Scholar
Timokhin, A. N. & Arons, J. 2013 Current flow and pair creation at low altitude in rotation-powered pulsars’ force-free magnetospheres: space charge limited flow. Mon. Not. R. Astron. Soc. 429, 20.CrossRefGoogle Scholar
Timokhin, A. N. & Harding, A. 2015 On the polar CAP cascade pair multiplicity of young pulsars. Astrophys. J. 810, 144.CrossRefGoogle Scholar