INFORMATION ABOUT PROJECT,
SUPPORTED BY RUSSIAN SCIENCE FOUNDATION

The information is prepared on the basis of data from the information-analytical system RSF, informative part is represented in the author's edition. All rights belong to the authors, the use or reprinting of materials is permitted only with the prior consent of the authors.

COMMON PART

Project Number24-22-00120

Project titleRadiation and propagation of radio waves in strongly magnetized astrophysical flows

Project LeadBeskin Vasily

AffiliationMoscow Institute of Physics and Technology,

Research area 02 - PHYSICS AND SPACE SCIENCES, 02-704 - Physics and evolution of stellar and interstellar medium

Keywordsneutron stars, active galactic nuclei, jets, Magnetohydrodynamics, plasma, radiative transfer, numerical modelling

PROJECT CONTENT

Annotation
The project is devoted to the study of the mechanisms of radiation and propagation of radio waves in highly magnetized astrophysical flows, specific for the magnetospheres of radio pulsars and jets from active galactic nuclei. Despite the significant difference between these astrophysical sources, many aspects of this issue turn out to be similar. This is due to the fact that, both in the case of active nuclei and in the case of radio pulsars, significant progress has recently been made in the study of internal structure of magnetized relativistic flows, which, in turn, made it possible to reach a new level in the detected radio emission analysis. Thus, for radio pulsars, it opens up the possibility of calculating mean intensity profiles taking into account the refraction of an ordinary wave, cyclotron absorption, and the limiting polarization effect considering the real transverse distribution of the density and energy spectrum of the outflowing plasma. In turn, for jets from active galactic nuclei, it became possible to quantitatively analyze the influence of such previously undiscussed processes, such as, for instance, the dependence of the spectrum and angular distribution of radiating particles on the distance to the central engine. As a result, it is supposed to build working models that allow the most complete modeling of the observed radio emission from these objects. The relevance of this study related to significant progress in the field of observations (the LOFAR and MeerKAT observatories should reach full capacity), the publication of large arrays of high-quality data on the intensity and polarization profiles of radio pulsars is expected over the next year. Accordingly, significant progress in the interferometry of jet emission from active nuclei, associated with the transition to the millimeter range, has also led to the emergence of a large amount of new and unique information that requires thoughtful processing. As a result, a much more accurate statistical analysis of observational data will become possible, which, along with numerical simulation supposed to be carried out as part of the project, will make it possible to verify existing theoretical models regarding the structure of the magnetosphere and the radio emission mechanisms of these compact astrophysical sources.

Expected results
For the first time, a model of the formation of the observed average profiles of radio pulsars will be constructed. The effects of propagation in the outflowing plasma, the density of which is not assumed to be uniform, but varies significantly in the cross section will be taken into account. It is supposed to solve the following tasks: 1) Determination of the role of the energy spectrum of the outflowing plasma on cyclotron absorption, and, as a result, on the shape of the mean profile. 2) 3D numerical modeling of radio emission transfer in the magnetosphere of a radio pulsar with self-consistent consideration of such effects as a refraction, cyclotron absorption, and the limiting polarization effect to construct the observed mean profiles. 3) Analysis of the emission of orthogonal interpulse pulsars, in which the transverse distribution of the outflowing plasma density strongly differs from the axisymmetric one. 4) Statistical analysis of the latest data on average intensity profiles and polarization structure of radio pulsar radiation in the context of existing theoretical models of the magnetosphere. 5) Creation of an interface that allows one to calculate mean intensity profiles, linear and circular polarization for each pulsar. As for relativistic jets, all components that determine their observed characteristics will be critically analyzed. This will make it possible to make significant progress in constructing a quantitative model of their radiation. It is supposed to obtain the following original results. 1) The law of evolution of the energy spectrum of radiating particles will be determined with a help of transverse adiabatic invariant conservation as the particles propagate along the jet. 2) The evolution of the angular distribution of radiating particles will be analyzed, taking into account their propagation and radiation. 3) Maps of the brightness temperature, linear and circular polarization, as well as the spectral index will be built using the previously obtained density profiles of the outflowing plasma, as well as the properties of radiating particles obtained within the framework of the project. 4) Based on the obtained maps, the dependences of the jet width on the distance to the central black hole will be predicted and compared with observational data; this will provide unique information about the properties of the outflowing plasma. 5) An interface will be created that allows building jet maps on their internal scales.

REPORTS