Structure and Features of the Galactic Magnetic-Field Reversals Formation

Abstract

At the present time, the induction of several microgauss in large-scale fields of the Galaxy has been repeatedly confirmed. There are numerous arguments in favor of the fact that the magnetic field exhibits so-called reversals associated with a direction change from one region to another. Such configurations are allowed in the nonlinear equations context of the dynamo theory, which describes the large-scale magnetic-field evolution. In the present study, reversals are modeled using the so-called no-z approximation based on the fact that the galactic disk is sufficiently thin. The magnetic field generation that exhibit both single and double sign changes with distance from the center is observed. From an observational point of view, one of the main methods for studying magnetic fields is to gauge the Faraday rotation measure of radio waves coming from pulsars. Its value can characterize the integral magnitude of the magnetic field, and the sign indicates its direction. A study of the pulsar distribution with large Faraday rotation measures ($$\left| {RM} \right| > 200$$ rad/m2) is presented. The results indicate that there is a region of $$4.8\;{\text{kpc}} < r < 7.3\;{\text{kpc}}$$ in the Galaxy in which the magnetic field is oriented counterclockwise. At the ring edges, the magnetic field reverses its direction. These results are in close agreement both with theoretical concepts and other studies dedicated to the structure observations of the magnetic field in the Galaxy.