Pair formation above pulsar polar caps: Structure of the low altitude acceleration zone

Journal Article · Wed Aug 01 04:00:00 EDT 1979 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/157250· OSTI ID:5874401

Arons, J; Scharlemann, E T

Solutions are presented for the space-charge-limited flow of electrons above the polar caps of a pulsar whose magnetic moment has a component parallel to its spin angular momentum, when the accelerating electric field is shorted out by the formation of electron-positron pairs. Only the oblique rotator is considered. Some predictions of the soft X-ray luminosity of the polar caps of the Vela pulsar are made, based on the heating of the star's polar caps by the back flux of positrons., with results in accord with the known maximum periods for pulsars, if the surface field has sufficient complexity. Estimates of the final density and momentum distribution function of the pairs are given. The power generated by each polar acceleration zone is shown to be L/sub pole/approx.5 x 10/sup 30/P/sup -19/8/ ergs s/sup -1/ if the surface magnetic field has strength approx.10/sup 12/ gauss, sufficient to explain most radio pulsars but insufficient to account for the X-ray and ..gamma..-ray emission from the Crab pulsar. A mechanism for further energization of the pair plasma at high altitude is proposed, based on the interaction between the plasma and the partial vacuum zone surrounding the plasma stream. It is pointed out that the model is consistent with the phenomenological hollow cone model for pulsar wave forms and with the single-pole interpretation of interpulses, since the flow is asymmetric with respect to the magnetic axis. Some predictions of the soft X-ray luminosity of the polar caps of the Vela pulsar are made, based on the heating of the star's polar caps by the back flux of positrons.

• Research Organization: Department of Astronomy and Space Sciences Laboratory, University of California at Berkeley
• OSTI ID: 5874401
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 231:3; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACCELERATION
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
BOUNDARY CONDITIONS
COSMIC RADIO SOURCES
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
DIFFERENTIAL EQUATIONS
ELECTRIC FIELDS
ELECTROMAGNETIC RADIATION
ELECTRONS
ELEMENTARY PARTICLES
EQUATIONS
FERMIONS
FLUID MECHANICS
GAMMA RADIATION
HYDRODYNAMICS
INTERACTIONS
IONIZING RADIATIONS
LEPTONS
MAGNETIC FIELD CONFIGURATIONS
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
MATHEMATICAL MODELS
MECHANICS
MOTION
NEUTRON STARS
PAIR PRODUCTION
PLASMA
PLASMA ACCELERATION
POISSON EQUATION
POSITRONS
PULSARS
RADIATIONS
ROTATION
STAR MODELS
STARS