Krasilchtchikov A.M., Kholupenko E.E., Badmaev D.V., Bodganov A.A. «Modeling of performance enhancement of the TAIGA-IACT Cherenkov gamma-ray telescope equipped with semiconductor photomultipliers» Научно-технические ведомости Санкт-Петербургского государственного политехнического университета. Физико-математические науки, 16, № S1.2, с. 423-428 (2023)

We present modeling of effective area and count rates of a TAIGA-IACT Cherenkov gamma-ray telescope unit with an upgraded camera based on semiconductor photo detectors (SiPM) OnSemi MicroFJ-60035 and optical filters SL 290-590 and SL 280-390. In comparison with the current configuration of TAIGA-IACT where classic vacuum photomultipliers are employed, the threshold detection energy of cosmic gamma-quanta by a TAIGA-IACT unit equipped with a SIiPM-based camera and a wide-band optical filter SL 290590 would be reduced down to about 0.4 TeV, and with a narrower filter SL 280–390 down to about 0.7 TeV. Application of semiconductor photo detectors, which are stable against excess illumination, and optical filters of the near-UV band allows one to substantially increase the duty cycle of a Cherenkov gamma-ray telescopes due to the possibility to carry out observations during moonlit nights and at twilight even without a need to substantially increase the trigger threshold. Hence, one may conclude that a TAIGA-IACT unit with an upgraded camera with SiPM detectors will be an efficient instrument for studies of TeV-range emission from space gamma-ray objects.

Kuznetsov V.I., Bakaleinikov L.A., Flegontova E.Yu. «Stability of steady states of plasma diodes with counter-streaming electron and positron flows» Научно-технические ведомости Санкт-Петербургского государственного политехнического университета. Физико-математические науки, 16, № S1.2, с. 442-448 (2023)

Stability of steady states of a planar geometry diode with counter flows of electrons and positrons is studied. The study is related to the elucidation of pulsar RF radiation nature. The equation for the electric field perturbation is derived. Its exact solution is obtained for the case of a homogeneous steady-state field. The study of the dispersion equation obtained has shown that there is a threshold for the inter-electrode gap value, above which steady-state solutions are unstable. The instability threshold turned out to be √2 times higher than the known Pierce threshold.

Kosenko D.N., Balashev S.A. «HD molecules in the Magellanic Clouds» Научно-технические ведомости Санкт-Петербургского государственного политехнического университета. Физико-математические науки, 16, № S1.2, с. 436-441 (2023)

We present the detection of HD absorption lines in the Magellanic Clouds using FUSE space telescope archival data. We found HD in five (including one known) absorption systems in the Large Magellanic Cloud and three systems in the Small Magellanic Cloud. The measured HD column densities, N(HD), vary from 2·10¹³ to 2·10¹⁵ cm^–2 for associated H2 column densities, NH₂, in the range 3·10¹⁹ to 5·10²⁰ cm^–2. Using Hubble Space Telescope archival data, we also determined the population of CI fine-structure levels and metallicities in these systems. The modelling of obtained observational data for HD, H2 and C I allow us to estimate physical conditions in the interstellar medium of the Magellanic Clouds associated with these absorption systems, namely, the cosmic ray ionization rate, ultraviolet field intensity and number density.

Balashev S.A., Kosenko D.N. «Neutral carbon in the diffuse cold neutral medium» Научно-технические ведомости Санкт-Петербургского государственного политехнического университета. Физико-математические науки, 16, № S1.2, с. 499-504 (2023)

We discuss the relative abundance of C I/H2 in the diffuse cold neutral medium. Using semi-analytical formalism, we describe how C I/H2 depends on the main parameters of the medium: number density, metallicity, strength of the UV field and cosmic ray ionization rate. We show that observed relative abundance of C I/H2 in the high-redshift damped Lyman alpha systems can be reproduced within our model assuming the typical expected conditions in the diffuse cold medium. We also discuss that the observed relative abundance of C I/H2, when coupled with data on the population of the fine structure levels of neutral carbon and the rotational levels of molecular hydrogen can be used to derive the cosmic ray ionization rate in the low-metallicity interstellar medium.

Popov A.N., Barsukov D.P., Ivanchik A.V., Bobashev S.V. «Positron production due to interaction of cosmological background photons» Научно-технические ведомости Санкт-Петербургского государственного политехнического университета. Физико-математические науки, 16, № S1.2, с. 429-435 (2023)

The interaction of photons of the cosmological background radiation with producing electron-positron pairs is considered. It is shown that main input in positron production is given by interaction of cosmological gamma-ray background photons with photons of extragalactic background light, although taking into account the interaction of cosmological gamma-ray background photons with cosmological ultraviolet background photons may substantially increase the pair production rate.

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.

Popov A.N., Barsukov D.P., Ivanchik A.V., Bobashev S.V. «Positron production due to interaction of cosmological background photons» Научно-технические ведомости Санкт-Петербургского государственного политехнического университета. Физико-математические науки, 16, № S1.2, с. 429-435 (2023)

The interaction of photons of the cosmological background radiation with producing electron-positron pairs is considered. It is shown that main input in positron production is given by interaction of cosmological gamma-ray background photons with photons of extragalactic background light, although taking into account the interaction of cosmological gamma-ray background photons with cosmological ultraviolet background photons may substantially increase the pair production rate.

Bodganov A.A., Repman G.A., Tuboltsev Yu.V., Chichagov Yu.V., Kholupenko E.E., Krasilchtchikov A.M. «Development of detector cluster based on silicon photomultipliers for the Cherenkov gamma-ray telescope TAIGA-IACT» Научно-технические ведомости Санкт-Петербургского государственного политехнического университета. Физико-математические науки, 16, № S1.2, с. 410-416 (2023)

A new experimental detector cluster for the TAIGA-IACT telescope has been developed. The cluster contains 28 pixels based on MicroFJ-60035 silicon photomultipliers, whose signal is digitized with an analog memory chip (switched capacitor array) DRS4 at a frequency of up to 5 GHz. The paper describes the device and the operation principles of the detector cluster, reveals the peculiarities encountered in the development process. Dark chamber tests of the cluster with a point source of short pulses of ultraviolet light have allowed us to obtain dependencies of the cluster conversion coefficient and the maximum value of the recorded signal on the overvoltage of the silicon detectors.

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.

Krasilchtchikov A.M., Kholupenko E.E., Badmaev D.V., Bodganov A.A. «Modeling of performance enhancement of the TAIGA-IACT Cherenkov gamma-ray telescope equipped with semiconductor photomultipliers» Научно-технические ведомости Санкт-Петербургского государственного политехнического университета. Физико-математические науки, 16, № S1.2, с. 423-428 (2023)

We present modeling of effective area and count rates of a TAIGA-IACT Cherenkov gamma-ray telescope unit with an upgraded camera based on semiconductor photo detectors (SiPM) OnSemi MicroFJ-60035 and optical filters SL 290-590 and SL 280-390. In comparison with the current configuration of TAIGA-IACT where classic vacuum photomultipliers are employed, the threshold detection energy of cosmic gamma-quanta by a TAIGA-IACT unit equipped with a SIiPM-based camera and a wide-band optical filter SL 290590 would be reduced down to about 0.4 TeV, and with a narrower filter SL 280–390 down to about 0.7 TeV. Application of semiconductor photo detectors, which are stable against excess illumination, and optical filters of the near-UV band allows one to substantially increase the duty cycle of a Cherenkov gamma-ray telescopes due to the possibility to carry out observations during moonlit nights and at twilight even without a need to substantially increase the trigger threshold. Hence, one may conclude that a TAIGA-IACT unit with an upgraded camera with SiPM detectors will be an efficient instrument for studies of TeV-range emission from space gamma-ray objects.

Bolotnova R.Kh., Korobchinskaya V.A. «Formation of supersonic steam-water jets accompanied by generation of acoustic pulsations» Научно-технические ведомости Санкт-Петербургского государственного политехнического университета. Физико-математические науки, 16, № S1.2, с. 330-336 (2023)

The features of supersonic steam-water jets formation under outflow through a thin nozzle from a high-pressure chamber are considered. The modes of emerging vibration processes are investigated, depending on variation of initial saturation states determined by pressure and temperature. The proposed model equations system of steam-water mixture in three-dimensional formulation, in two-temperature, single-pressure, single-velocity approximations, takes into account interphase heat exchange, evaporation and condensation phenomena. The numerical implementation of this problem is carried out by the authors developed solver in the OpenFOAM package. The process of evolution a supersonic jet with formation Mach disk is studied and the causes of generation a pressure acoustic pulsations are investigated. The analysis of influence of initial saturation states of vapor-water fluid located in a high-pressure chamber on intensity and frequency of acoustic vibrations is given. To justify the reliability numerical method in the OpenFOAM package, the obtained solution with experimental photograph of supersonic nitrogen jet owing through cylindrical nozzle from a high-pressure chamber is compared.

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.

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.

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.

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.

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.

Uvarov Yu.A., Bykov A.M. «Asymmetry study of the mixed-morphology supernova remnant G 18.95-1.1» Научно-технические ведомости Санкт-Петербургского государственного политехнического университета. Физико-математические науки, 16, № S1.2, с. 362-369 (2023)

Radio and X-ray maps of supernova remnants (SNRs) in many cases revealed an asymmetric global structure. This may reflect the inhomogeneity of the circumstellar/ambient matter, anisotropic energy release or both. Given a growing sample of the observed SNRs some techniques to characterize the global asymmetry are needed to identify old SNRs in sky surveys among other observed extended structures of low surface brightness. We discuss here the applications of modified power-ratio technique to quantify the global asymmetry of the mixed-morphology SNR G 18.95-1.1 using its recent mapping with SRG and compare results with the well-studied SNRs IC 443 and Cas A.

Romansky V.I., Bykov A.M., Osipov S.M. «Kinetic modeling of MHD parameters of mildly-relativistic shocks» Научно-технические ведомости Санкт-Петербургского государственного политехнического университета. Физико-математические науки, 16, № S1.2, с. 461-466 (2023)

Mildly-relativistic outflows with shocks of velocities 0.1–0.7c were deduced from multiwavelength observations of powerful fast transient sources. These outflows are associated with merging relativistic objects, relativistic supernovae and fast blue optical transients. Relativistic magneto-hydrodynamic (RMHD) models of these objects rely on the equation of state of the fluid, which is a collisionless plasma with a contribution of non-thermal components. In this paper, we present kinetic simulations of mildly-relativistic shocks with Particle-in-Cell and Monte-Carlo techniques to derive the adiabatic index of plasma in the shock downstream directly from the particle distributions, which can be implemented into the RMHD models.