Lukyantsev D.S., Afanasiev N.T., Tanaev A.B. «Mathematical modeling of effects of plasma and gravitational inhomogeneities in the structure of electromagnetic signals» Научно-технические ведомости Санкт-Петербургского государственного политехнического университета. Физико-математические науки, 16, № S1.2, с. 377-382 (2023)

The three-dimensional algorithm of calculation of the trajectory characteristics of electromagnetic signals in a random-inhomogeneous space plasma placed in the gravity field of difficult configuration has been suggested. The influence of the gravity on the signal propagation has been taken into account by the use of efficient index of refraction. The inhomogeneities of plasma have been defined by the model of spatial correlation function of fluctuations of index of refraction. Results of mathematical modeling of lensing of electromagnetic signals in the gravity field from several space objects have been provided. It is shown that, a significantly different spatial structure of ray field can occur in picture plane of the observer depending on the properties of the gravitational field and parameters of random plasma inhomogeneities.

Chudaev S.O., Afanasiev N.T., Lukyantsev D.S. «Diagnostics of CME cavity using data of multiwave measurements of behind-the-limb solar radio bursts» Научно-технические ведомости Санкт-Петербургского государственного политехнического университета. Физико-математические науки, 16, № S1.2, с. 383-388 (2023)

Mathematical modeling of the behind-the-limb radio bursts propagation characteristics at the second harmonic of the local plasma frequency of the solar corona was performed for analytical models of the electron density of the circumsolar plasma and CMEs. The features of the bursts trajectories are studied depending on the parameters of the CMEs and the initial coordinates of solar radio sources. The conditions for the strong effect of CME on radio bursts are determined. The possibility of determining the CME cavity’s parameters from the data of multiwave measurements of the group delays of behind-the-limb radio bursts is shown.

Amorim D.O., Гудкова Т.В. «Внутреннее строение Венеры на основе модели PREM» Астрономический вестник. Исследования Солнечной системы, 57, № 5, с. 403-414 (2023)

Построены модели внутреннего строения Венеры с широким диапазоном толщины коры (30–70 км) и радиуса ядра (2800–3500 км). Анализ полученных значений давления в центре планеты позволяет заключить, что наличие твердого внутреннего ядра маловероятно, если состав и температурный профиль Венеры соответствуют земному. Для учета неупругости недр Венеры при расчете приливных чисел Лява и угла запаздывания приливного горба применена реология Андраде. Сравнение экспериментальных значений числа Лява k2 с модельными дает радиус ядра Венеры в диапазоне 3100–3500 км. Показано, что для определения характерной вязкости мантии Венеры ключевым фактором служит определение угла запаздывания приливного горба: значения 0.9° соответствуют низкой вязкости и высокой температуре, а 0.4° – высокой вязкости и низкой температуре, поэтому планируемые измерения приливных параметров и момента инерции планеты в миссиях VERITAS и EnVision смогут наложить ограничения на распределение вязкости и температуры в недрах Венеры.

Andreev A.O., Nefedyev Yu.A., Demina N.Yu., Kolosov Yu.A., Korchagina E.P. «Multiparametric analysis of celestial bodies as sources of space resources» Научно-технические ведомости Санкт-Петербургского государственного политехнического университета. Физико-математические науки, 16, № S1.2, с. 511-516 (2023)

The work is devoted to the creation of a method based on data from space missions such as LRO (Lunar Reconnaissance Orbiter) and the analysis of possible impactors and meteoroid material for mapping the distribution of minerals on the Moon. In the process of surveys from the Lunar Reconnaissance Orbiter (LRO) spacecraft, the most recent generalized information on the distribution of iron and titanium in the composition of the lunar surface rocks was obtained. To obtain these data, it was necessary to compile a single map from more than 4 thousand images that the LRO spacecraft took during a month of work in a lunar orbit. The processing of the obtained data made it possible to detect areas on the lunar surface containing significant deposits of titanium. The results were calibrated using analyzes of lunar soil samples brought to Earth by the American Apollo missions and Soviet automatic vehicles of the Luna series. Concrete results obtained: Map of mineral distribution gradients depending on selenographic coordinates on the lunar sphere.

Zagidullin A.A., Petrova N.K., Nefedyev Yu.A., Andreev A.O. «Creation of a generalized dynamic model of planetary moons based on an analytical approach for describing the libration processes of their rotation» Научно-технические ведомости Санкт-Петербургского государственного политехнического университета. Физико-математические науки, 16, № S1.2, с. 517-522 (2023)

Our work is devoted to the creation of a generalized dynamic model that describes libration processes in the motion of the natural satellite of the planet, which has been tested on the simulation of the moons rotational parameters(MRPs) of the Earth’s Moon and allows adapting description system of MRPs to other celestial objects, having a librational nature of rotation as well. In this case, it is assumed that an analytical approach was used to describe the rotational motion, which, on the one hand, is rather complicated for solving the equations of rotation and has a lower accuracy than the numerical one, but, on the other hand, the resulting analytical representation of MRPs provides a more convenient tool for analyzing the behavior of MRPs with changes in various parameters, determining the rotational dynamics of the satellite.It is with its help that the procedure of flexible computer simulation of the rotation process and the identification of those observational manifestations, which are determined primarily by the parameters of the figure of a celestial body – the laws of distribution of body mass, compression, non-sphericity.

Sergienko M.V., Sokolova M.G., Nefedyev Yu.A., Andreev A.O. «ρ-Geminids meteor shower and its connection with near-earth asteroids» Научно-технические ведомости Санкт-Петербургского государственного политехнического университета. Физико-математические науки, 16, № S1.2, с. 523-529 (2023)

In this work, genetic connections (GC) of the small meteor shower ρ-Geminids with near-Earth objects (NEOs) of the Apollo group were studied using the author’s multi-parameter method. The multiparameter method for determining GC of meteor showers with probable parent bodies is based on the use of a set of criteria for identifying orbits, such as: D-criterion by Drummond, Kholshevnikov’s metric, Tisserand’s parameter, μ and ν quasi-stationary parameters of the restricted three-body problem, longitude of perihelion π of meteor orbit. The method of identifying meteoroids with asteroids involves computational procedures and the calculation of critical values for each of the criteria used, which increases the reliability of finding the GC for the objects under study. The catalogues of meteor orbits: Meteoroid Orbit Database v3.0, CAMS and EDMOND 5 v.04 of the European Meteor Network were used as source material in the work.

Churkin K.O., Andreev A.O., Nefedyev Yu.A., Kolosov Yu.A., Korchagina E.P., Demina N.Yu., Borovskih V.S. «Analysis of comet C/1969 Y1 parameters using isophote structural modeling» Научно-технические ведомости Санкт-Петербургского государственного политехнического университета. Физико-математические науки, 16, № S1.2, с. 530-535 (2023)

This work is devoted to the construction of a brightness structural model of the long-period comet Bennett C/1969 Y1. This comet belongs to the comets of the Jupiter family (JF) and has a Tisserand’s parameter T>2. Determining the brightness characteristics of the comet has been one of the most important goals of cometary observations over the past century. The complexity of such studies lies in the fact that we are dealing with extended sources moving relative to background stars. The problem of obtaining reliable estimates of the distribution of brightness parameters (BPs) for long-period comets also remains especially important, because for many of them observations were made back in the days when high-precision methods, such as CCD-matrices and other technical tools, were not available. At the same time, most of the determined stellar magnitudes of long-period comets were related to the gaseous coma surrounding the comet’s nucleus, and not to the comet’s nucleus itself. At the same time, cosmic ultraviolet observations of comets in the Lyman-alpha hydrogen lines made it possible to obtain very important data for estimating the emission of H₂O by the cometary nucleus, as well as other types of molecules (e.g. C₂, C₃, CN, OH). In the presence of dependencies between the productivity of the H₂O cometary nucleus and its brightness characteristics, the determination of BPs of cometary nuclei has acquired a new meaning. However, the dependence of the size of the nucleus on its BPs is not linear, since there is a correlation with the albedo of the surface of the nucleus. In this work, BPs and albedo for comet Bennett C/1969 Y1 are studied. Taking into account the data obtained and the solution of the described problems, we applied the author’s isophote method to analyze the structure of the brightness characteristics of Bennett C/1969 Y1.

Antonov A.S., Bodganov A.A., Krasilchtchikov A.M. «Design of an optical concentrators array for the camera of a small-size Cherenkov gamma-ray telescope» Научно-технические ведомости Санкт-Петербургского государственного политехнического университета. Физико-математические науки, 16, № S1.2, с. 417-422 (2023)

Quantitative modeling of a system of optical concentrators based on an improved design of Winston hexagonal cones, providing a possibility of using light filters and intended for the registration camera of a small-size Cherenkov gamma-ray telescope, has been performed. The transmission of the cones is calculated, and the intensity distributions of the photon flux in the detector plane are given. Based on the results obtained, an optimal configuration of optical concentrators is proposed with an account for design features of the TAIGA-IACT mount, mirror, and camera, as well as of new detector units. The results obtained for the considered system are compared with the previously published models.

Ivanova A.L., Astapov I.I., Bezyazeekov P.A., Bonvech E.A., Borodin A.N., Budnev N.M., Bulan A.V., Chernov D.V., Chiavassa A., Dyachok A.N., Gafarov A.R., Garmash A.Yu., Grenebyuk V.M., Gres E.O., Gres O.A., Gres T.I., Grinyuk A.A., Grishin O.G., Ivanova A.D., Ilushin M.A., Kalmykov N.N., Kindin V.V., Kiryukhin S.N., Kokoulin R.P., Kompaniets K.G., Korosteleva E.E., Kozhin V.A., Kravchenko E.A., Kryukov A.P., Kuzmichev L.A., Lagutin A.A., Lavrova M.V., Lemeshev YU.E., Lubsandorzhiev B.K., Lubsandorzhiev N.B., Malakhov S.D., Mirgazov R.R., Monkhoev R.D., Okuneva E.A., Osipova E.A., PakhorukoV A.L., Pankov L.V., Pan A., Panov A.D., Petrukhin A.A., Podgrudkov D.A., Popova E.G., Postnikov E.G., Prosin V.V., Ptuskin V.S., Pushnin A.A., Raikin R.I., Razumov A.YU., Rubtsov G.I., RYABOV E.V., Samoliga V.S., Satyshev I., Sidorenkov A.YU., Silaev A.A., Silaev A.A., Tarashchansky B.A., Tkachev L.G., Tanaev A.B., Ternovoy M.YU., Ushakov N.A., Volchugov P.A., Volkov N.V., Voronin D.M., Zagorodnikov A.V., Zhurov D.P., Yashin I.I., Vaidyanathan A. «Technique for reconstructing the parameters of eas and primary cosmic rays based on experimental data of the Tunka-Grande scintillation array» Научно-технические ведомости Санкт-Петербургского государственного политехнического университета. Физико-математические науки, 16, № S1.2, с. 389-394 (2023)

The Tunka-Grande scintillation array is a part of a single TAIGA experimental complex located in the Tunka Valley, 50 km from the Lake Baikal. It consists of 19 observation stations deployed on an area of about 0.5 km². The main aim of the Tunka-Grande facility is a detailed study of the energy spectrum and mass composition of cosmic rays in the energy range from 10 PeV to 1 EeV by detecting the charged and muon component of EAS. The article presents a method for reconstructing the parameters of the EAS and primary cosmic rays, the cosmic rays energy spectrum based on 4 measurement seasons, and compares the results obtained with the data of the Tunka-133 and TAIGA-HiSCORE Cherenkov arrays.

Monkhoev R.D., Astapov I.I., Bezyazeekov P.A., Bonvech E.A., Borodin A.N., Budnev N.M., Bulan A.V., Vaidyanathan A., Volkov N.V., Volchugov P.A., Voronin D.M., Gafarov A.R., Gres E.O., Gress O.A., Gress T.I., Grishin O.G., Garmash A.Y., Grebenyuk V.M., Grinyuk A.A., Dyachok A.N., Zhurov D.P., Zagorodnikov A.V., Ivanova A.D., Ivanova A.L., Iliushin M.A., Kalmykov N.N., Kindin V.V., Kiryukhin S.N., Kokoulin R.P., Kolosov N.I., Konstantin G.C., Korosteleva E.E., Kozhin V.A., Kravchenko E.A., Kryukov A.P., Kuzmichev L.A., Chiavassa A., Lagutin A.A., Lavrova M.V., Lemeshev Y.E., Lubsandorzhiev B.K., Lubsandorzhiev N.B., Malakhov S.D., Mirgazov R.R., Okuneva E.A., Osipova E.A., Pakhorukov A.L., Pan A., Panov A.D., Pankov L.V., Petrukhin A.A., PodgrudkoV D.A., Popova E.G., Postnikov E.B., Prosin V.V., Ptuskin V.S., Pushnin A.A., Razumov A.Y., Raikin R.I., Rubtsov G.I., Ryabov E.V., Samoliga V.S., Satyshev I., Silaev A.A., Silaev A.A., Sidorenkov A.Y., Skurikhin A.V., Sokolov A.V., Sveshnikova L.G., Tabolenko V.A., Tanaev A.B., Tarashchansky B.A., Ternovoy M.Y., Tkachev L.G., Ushakov N.A., Chernov D.V., Yashin I.I «Method for gamma-hadron separation according to the experimental data of the Tunka-Grande array» Научно-технические ведомости Санкт-Петербургского государственного политехнического университета. Физико-математические науки, 16, № S1.2, с. 480-484 (2023)

The Tunka-Grande array is a part of unified experimental complex, which also includes Tunka-133 and TAIGA-HiSCORE (High Sensitivity COsmic Rays and gamma Explorer) wide-angle Cherenkov arrays, TAIGA-IACT array (Imaging Atmospheric Cherenkov Telescope) and TAIGA-Muon scintillation array. This complex is located in the Tunka Valley (Buryatia Republic, Russia), 50 km from Lake Baikal. It is designed to study the energy spectrum and the mass composition of charged cosmic rays in the energy range 100 TeV-1000 PeV, to search for diffuse gamma rays above 100 TeV and to study local sources of gamma rays with energies above 30 TeV. This report outlines 3 key points. The first is the description of the Tunka-Grande scintillation array. The second one presents the strategy of the search for diffuse gamma rays based on a computer simulation of the Tunka-Grande array. The third one is devoted to the prospects for future research in the field of gamma-ray astronomy using simulation results.