arXiv subjects

F. A. Kniazev

Publications and source records attributed to F. A. Kniazev.

4 recordsLinked to original sources

arXiv2026

Synchrotron radiation in nonuniform magnetic field

The distortion of the spectrum of synchrotron radiation received by a distant observer due to magnetic field inhomogeneity is discussed. It is shown that for single-particle radiation, a noticeable difference in the integrated spectrum from the case of a uniform magnetic field occurs only for observation times significantly exceeding the observer's departure from the beam pattern, and only for subrelativistic particles, when the radiation arrives from regions with significantly different magnetic fields during the observation time. For shorter observation times, field inhomogeneity leads only to small-scale distortions (smaller or comparable in frequency to the gyrofrequency) and does not manifest itself in the averaged spectrum. For the case of a particle ensemble, which is of interest for astrophysical applications, the difference in the integrated spectrum becomes negligible.

astro-ph.HE↗

arXiv2025

Data from FAST and MeerKAT surveys as a test of radio pulsar physics

The data from the FAST and MeerKAT surveys has significantly increased the number of radio pulsars for which the polarization characteristics of their mean profiles have been determined in detail. This has allowed us to confirm earlier conclusions both about the nature of propagation of two orthogonal modes in the pulsar magnetospheres and about the mechanism of particle production in neutron star polar regions and their evolutionary features. We can now say with even greater confidence that mean profiles formed by the O-mode are significantly wider than those formed by the X-mode. Moreover, the observations confirm the validity of the classical Ruderman-Sutherland vacuum model of particle generation, as well as the evolution of the inclination angles of the magnetic axis to the rotation one in the direction of $90^{\circ}$.

astro-ph.HE↗

arXiv2025

Acceleration Potential and Density Profile of Secondary Plasma in the Magnetosphere of Orthogonal Pulsars

A new method for determining the accelerating potential above the polar caps of radio pulsars with an arbitrary inclination angle of the magnetic axis to the rotation axis has been proposed. The approach has been based on the concept of a vacuum gap, the height and shape of the upper boundary of which are found self-consistently together with the solution of the corresponding Poisson equation. In turn, information about the accelerating potential has made it possible to determine the transverse profiles of the secondary plasma density. It has also been shown that the effect of inverse Compton scattering on the considered processes is insignificant.

astro-ph.HE↗

arXiv2023

On the Internal Structure of Relativistic Jets with Zero Velocity Along the Axis

The present work is devoted to the analysis of the internal structure of relativistic jets under the condition that the velocity of the plasma flow at the jet axis vanishes. It is shown that in spite of the seemingly fundamental difference in the formulation of the problem at the axis, the key properties of the internal structure of such relativistic jets remain the same as for nonzero velocity along the axis. In both cases, at a sufficiently low ambient pressure, a dense core appears near the axis, the radius of which is close to the size of the light cylinder.

astro-ph.HE↗