Some problems of pulsar physics or I'm madly in love with electricity

Abstract

Some current topics in the theory of pulsar magnetospheres and their emission are reviewed. The mode of plasma supply and its consequences for structure of planetary and stellar magnetospheres is discussed. In the pulsar case, the plasma is supplied by electrical forces, in contrast to all other known examples. The resulting theories of particle acceleration along polar field lines are then reviewed, and the total energization of the charge separated plasma is summarized, when pair creation is absent. The effects of pair creation are reviewed using models of the resulting steady and unsteady flows, when the polar zones of the pulsar emit either electrons or ions. The application of these theories of acceleration and plasma supply to pulsars is discussed, with particular attention paid to the total amount of electron-positron plasma created and its momentum distribution. Qualitative agreement is shown between the spatial structure of the relativistically outflowing plasma described in one version of these models and the morphology of pulsar wave forms. Various aspects of radiation emission and transport are summarized, based on the polar current flow model with pair creation, and the phenomenon of marching subpulses is discussed. The corotation beaming and the relativistically expanding current sheet models for pulsar emission are also discussed briefly, and the paper concludes with a brief discussion of the relation between the theories of polar flow with pair plasma and the problem of the energization of the Crab Nebula.

Electrodynamics of Pulsar Magnetospheres

“…The topic has been discussed in many reviews, e.g. by Arons (1979); Michel (2004) and recently by Arons (2009Arons ( , 2012; Spitkovsky (2011); Bühler and Blandford (2014); Beskin et al (2015); Grenier and Harding (2015); Pétri (2016). We focus on the pulsar itself, i.e.…”

Enhanced Optical Emission from the Crab Pulsar

“…This mechanism is attractive as it can explain why the large radio pulses correspond to quite small optical changes as the density enhancements, n, increase the coherent emission (ex n 2 ) with little effect on the (high-energy) incoherent radiation (ex n). These changes must occur on tiny timescales « 10 Jjs) to explain the observed change in optical flux and the upper limit in the ,-ray region (Arons 1979). For further discussion please see Shearer et al (2003).…”

High-energy pulses and phase-resolved spectra by inverse Compton emission in the pulsar striped wind

“…Bogovalov & Aharonian (2000) used inverse Compton scattering of the unshocked wind on lowfrequency photons coming from the pulsar to compute the pulsed and unpulsed component of the gamma ray emission. However, for some criticism about pulsed radiation coming from outside the light-cylinder and related beaming effects, see Arons (1979).…”