In this talk, I will overview the recent studies of LHAASO in TeV-PeV gamma-ray astronomy, including our measurements on supernova remnants, pulsar wind nebulae, massive star clusters, microquasars, and diffuse emission from the Galactic Plane.
The proportional counters developed and operated by the GRAPES-3 experiment (Gamma Ray Astronomy PeV EnergieS Phase-3), Ooty, are gas-based detectors designed using mild steel rectangular tubes. The existing muon telescope of GRAPES-3, consisting of 3712 PRCs, has been in operation for the past few decades and data gathered by it has ensured the study of solar, atmospheric and cosmic muons....
The Experimental complex NEVOD includes a set of facilities for the investigation of extensive air showers (EAS). Two of them are: the Cherenkov water calorimeter (CWC) NEVOD and the NEVOD-EAS air-shower array. The CWC measures energy deposit of EAS cores. The NEVOD-EAS detects the EAS electron-photon component in the primary energy range of 1015-1017 eV and allows reconstructing the main...
Carpet-3 of BNO INR RAS is an array of scintillation detectors situated in Neutrino Village, Kabardino-Balkarain Republic, Russian Federation. It is meant to observe extensive air showers (EAS) with energies above 100 TeV.
We generated more than 200,000 EAS using CORSIKA 7.8000 with QGSJETIII and FLUKA2024 models from different primary particles: $\gamma$-quanta, protons, helium and iron...
The URAN array was constructed at the Experimental Complex NEVOD to study extensive air showers (EAS) in the energy range of 10¹⁵–10¹⁷ eV. The URAN array consists of 72 detectors combined into 6 clusters of 12 detectors and installed on the roofs of two buildings of the experimental complex. The array simultaneously detects both the electron-photon and hadronic (via thermal neutrons) EAS...
TAIGA (Tunka Advanced Instrument for Cosmic Rays and Gamma-Astronomy) is the largest gamma-ray observatory in Russia, designed for detection of the high-energy gammas in the range from several TeV to several PeV, as well as of the high-energy cosmic rays (CR) in range from 102 TeV to 103 PeV. A new EAS complex TAIGA-100 is based on the experience of the TAIGA observatory and is planned to be...
The report presents the results of development of an algorithm for determining the charge and energy of heavy ions based on the characteristics of the etched tracks in optically transparent solid-state detectors. Initially, the procedure was developed for the experiment to search for and identifying primary cosmic radiation nuclei registered in meteorite olivines, and their charge...
In our work we investigate specialized scintillators based on locally produced powdered phosphors immersed in an optically transparent silicone rubber. Scintillators of this type can be optimized for recording different types of particles. We present the results of studies of silicone rubber-based scintillators response to atmospheric muons, fast neutrons and radioactive background, mainly...
The SPHERE-2 telescope constructed for the registration of EAS by the Cherenkov light reflected from the snowed surface used a method for the shower classification by the primary mass based on the steepness of the light lateral distribution function on the telescope’s mosaic. The simulation shows that the classification errors for a criterion by the characteristics of the direct Cherenkov...
The prototype of the ENDA (Electron Neutron Detector Array) cluster was created on the territory of the INR RAS in Moscow (ENDA-INR). It consists of 16 electron-neutron detectors (en-detectors) and using to study EAS (Extensive Air Showers) with energy above 1 PeV. Its purpose is testing the registration methods and methods for signal processing. The paper describes the detectors calibration...
The energy estimation method is based on the inverse interpolation of the dependence of the
integral over the axially symmetric function approximating the EAS image on the distance from the
detector axis to the shower axis on the snow. For the approximation and the parameters derived
from it to be authentic the shower axis should hit the snow within the field of view of the telescope.
Due...
We present a study of the possibility of registering EAS simultaneously by the onshore detector facility and the Baikal Neutrino Telescope. Such a setup would allow obtaining experimental information on the number of muons in EAS with ultra-high energy. This, subsequently, would make it possible to examine EAS modeling programs and additionally to verify the atmospheric neutrino flux...
Many attempts have been made to develop accurate techniques for calibrating ground-based detectors using data from satellite instruments. Those will allow to reconstruct the actual cosmic ray fluxes, which are not distorted by interactions with the Earth's atmosphere. Such methods will significantly enhance the capabilities of ground-based detectors for monitoring and forecasting space weather...
The poster presents materials on the production of mirrors for atmospheric Cherenkov telescopes of the TAIGA project.
Due to the increase in the diameter of the telescope, the issue of reducing the mass of mirrors as a whole is becoming relevant, so much attention is now being paid to the development of technology for the production of composite mirrors.
The parameters of monolithic and...
Using data of ground-level cosmic ray observations at the worldwide network of neutron monitors, Yakutsk muon telescope and URAGAN muon hodoscope (Moscow) and the spectrographic global survey method, we calculated cosmic ray variations spectra and anisotropy, as well as changes in the planetary system of rigidities of geomagnetic cutoff during the Forbush effect of March 24th, 2024. At the...
Nowadays, the muonography method (by the analogy with the X-Ray radiography) has become widely used for studying various natural and industrial objects: the atmosphere and heliosphere, the mountains and volcanoes, the blast furnaces and nuclear reactors, the historical heritage sites, and others. The method is based on the "scanning" of thick layers of matter using the penetrating flux of...
One of the most relevant difficulties in the ultra-high energy cosmic ray (UHECR) physics is the so-called “muon puzzle”. It refers to the observed excess of muons in extensive air showers (EAS) induced by UHECR compared to the results of simulations. It is assumed that one possible solution of the “muon puzzle” could be the modification of hadronic interaction models. Some studies suggest an...
In December 2024, an upgraded data recording and processing system was put into operation at the Yakutsk extensive air shower (EAS) array, and an additional detector grid with a step of 250 m was deployed, which covers the central part of the array with an area of 0.16 km².
In this report we will describe the upgraded software package for event processing and present the first results of...
The Experimental Complex (EC) NEVOD includes a set of scientific facilities for studying extensive air showers (EAS): the Cherenkov water detector NEVOD, the calibration telescope system CTS, the coordinate detectors DECOR and TREK, the arrays of scintillation detectors URAN, PRISMA, NEVOD-EAS which measure different EAS components. In order to develop multicomponent EAS studies, the hardware...
This work presents a numerical simulation of the energy spectrum of atmospheric neutrinos. We model the propagation of Galactic Cosmic Ray (GCR) protons from the magnetosphere boundary to near-Earth space, followed by their subsequent interactions with the Earth's atmosphere, leading to the production of secondary particles. The simulation is performed using the GT software package [1],...
Perspectives and difficulties of using small (<1 m^2) particle detectors made with scintillating materials for measuring muon component of galactic cosmic rays will be discussed using the example of an experiment carried out at IZMIRAN in last 3 years.
Parameters of the instrument will be shown. Special attention will be given to methods of correcting the data for environmental effects,...
The description of the model and its construction blocks, i.e. EAS event processor, physical model of the reflected light telescope in Geant4 and the image handling procedure, is presented. The process of the optimization of the model and the processing conveyor is explained.
We provide the indication of high flux of $^{40}K$ geo-antineutrino and geo-neutrino ($^{40}K$-geo-($\bar{\nu}+\nu$)) with Borexino Phase III data. Simultaneously we obtained the count rates of events from $^{7}$Be, pep and CNO solar neutrinos. MC pseudo-experiments showed that the case of high metallicity Sun and absence of $^{40}K$-geo-($\bar{\nu}+\nu$) can not imitate the result of...
The TAIGA-100 astrophysical complex is a project of a large-scale facility designed to solve a wide range of fundamental problems in gamma ray astronomy, cosmic ray physics and particle astrophysics. It will include several types of detectors to record various components of extensive atmospheric showers over an area of 100 square kilometers.
A key aspect of the successful implementation of...
The TAIGA astrophysical complex [1], located in the Tunka Valley (Republic of Buryatia), covers an area of about 1.1 km² and is designed to study gamma rays with energies above 3-4 TeV and cosmic rays with energies above 200 TeV. The complex includes the TAIGA-IACT facility, which currently consists of four atmospheric Cherenkov telescopes.
TAIGA-IACT makes it possible to distinguish...
The Multipurpose Detector of Muons (MDM) is now under development at the National Research Nuclear University MEPhI. It is an array of multiwire drift chambers shielded with the layers of steel absorber. Such configuration enables the detection and analysis of both single-particle and multiparticle events across a zenith angle range from 0° to 60°.
The detector is designed for investigation...
Research on thunderstorm phenomena has been conducted for centuries, however, some fundamental questions remain unresolved. One of these is the mechanism of occurrence and propagation of lightning discharges. Initiated by high-energy (E > 10^15 eV) cosmic rays (CR) extensive air showers (EAS) can be one of the factors influencing the mechanism of lightning development. At the same time, the...
A cosmic ray flux, predominantly protons, is continuously present at the boundary of both the Earth's magnetosphere and atmosphere, and can be divided into galactic cosmic rays (GCR) and solar cosmic rays (SCR). While the GCR flux is isotropic and its proton spectrum has a wide energy range, the characteristics of SCR depend on solar activity, and their energies rarely exceed a few GeV....
At the present time, the studies of ultra-high energy cosmic rays can be carried out only at the ground-based facilities recording extensive air showers (EAS). The existing facilities for the cosmic ray research measure various components of extensive air showers using different detecting systems. Simultaneous detection of several EAS components using hybrid detectors will provide additional...
Cherenkov water calorimeter (CWC) NEVOD is the main part of the Experimental complex (EC) NEVOD designed to detect cosmic rays on the Earth’s surface. The CWC detection system represents a spatial lattice of the quasi-spherical modules (QSM), located at its nodes. The QSM is able to measure Cherenkov radiation practically in the entire solid angle of $4\pi$. Due to the modernization of the EC...
The Yakutsk EAS array is designed to study ultra-high-energy cosmic rays reaching the Earth's atmosphere. For more than 50 years, the Yakutsk array has maintained continuous operation. It is the longest-running experiment in the world to register ultra-high-energy cosmic rays. The current state, development prospects of the array, and the latest scientific results are presented.
Атмосферные черенковские телескопы (АЧТ) сегодня активно используются в гамма-астрономии. С их помощью регистрируют угловое распределение черенковского света широких атмосферных ливней (ШАЛ), инициированных первичными частицами высоких энергий. Наблюдения осложняются наличием постоянного фонового шума, например, свечение ночного неба, антропогенная засветка. Это приводит к снижении точности...
Проблема исследования спектров ядер дейтерия и трития является частью более общей проблемы изучения процессов ускорения и распространения космических лучей. В последние годы разные эксперименты показали заметные отличия в спектрах различных компонент, а также наличие дополнительного “колена” в спектре по магнитной жесткости. Эти эффекты требуют объяснения. Для решения проблемы необходима...
В послесвечении гамма-всплесков (GRB) могут встречаться гамма-кванты с энергией $E=1~ТэВ$ и более. Присутствие в спектре гамма-квантов высокой энергии можно обнаружить с помощью наземных установок, например, распределённых черенковских детекторов (HAWC, LHAASO), или же с помощью атмосферных черенковских телескопов (H.E.S.S, TAIGA-IACT).
При наличии автоматической системы быстрого наведения...
При регистрации гамма-источников атмосферными черенковскими телескопами большое количество наблюдаемых источников имеет не точечный характер, а протяженную форму. Это ухудшает точность их наблюдения одиночными телескопами или делает его полностью невозможным. Для решения этой задачи в астрофизическом комплексе TAIGA (51.813129°`с.ш., 103.071849° в.д.), где работают уже три телескопа, будет...
In 2021, LHAASO observed a large number of Pevatrons in the Milky Way, which pointed out the direction for the sensitivity design of the next generation astronomy neutrino telescope, and it is expected to observe the precious neutrino celestial point source in the Milky Way only by designing a telescope with at least 30 times the sensitive volume of the IceCube detector. Therefore, we proposed...
The Electron-Thermal Neutron Detector Array (ENDA) is located at Haizishan, Daocheng, Sichuan Province, China, at an altitude of 4410 meters. The scientific goal of ENDA is to measure the composition-resolved energy spectrum of cosmic rays, particularly in the knee region, through joint observations with LHAASO. Currently, 64 detectors, so called ENDA-64, have been deployed at the LHAASO site...
The prototype of the ENDA (Electron Neutron Detector Array) cluster was created on the territory of the INR RAS in Moscow (ENDA-INR). The concept of the ENDA consists in simultaneous registration of the electromagnetic and thermal neutron components (being a part of hadronic component) of the EAS. The report is devoted to the first experimental data of the prototype together with the simulation data.
ENDA-INR is a sea level prototype of the running now at high altitude in China ENDA (Electron-Neutron Detector array), being a part of the LHAASO experiment. The main task of the ENDA is measuring of primary cosmic ray energy spectrum using hadronic EAS component. The latter is a principal point because only hadrons form the EAS “skeleton” which defined all its properties at observation level....
Recently, the Large High Altitude Air Shower Observatory (LHAASO) published measurements of the all-particle CR energy spectrum and the mean logarithmic mass of CRs with unprecedented accuracy in 0.3 - 30 PeV. The mean logarithmic mass shows a nonmonotonic change with energy, a feature observed for the first time.
Phenomenological studies of the cosmic-ray flux and its mass composition in...
Based on measurements of magnetospheric electron fluxes with energies >2 MeV in geostationary orbits, solar wind (SW) velocity, and geomagnetic activity for the period 1995-2023, a catalog of electron flux enhancements has been compiled. For the events of this catalog, interplanetary disturbances have been determined, after which high-energy electron fluxes (HEEF) begin to increase, and their...
Daily vectors of solar-diurnal anisotropy of cosmic rays (CRs) are obtained based on the Climax neutron monitor (NM) data for 1953-2006. These results are compared with similar anisotropy vectors obtained with the Moscow NM data for 1966-2006 and by the global survey method for 1957-2006. During quiet periods, there is a good agreement between the results obtained with different datasets and...
The Large Volume Detector (LVD) located at the Gran Sasso Laboratory is designed to continuously search for neutrinos from stellar core collapses in our galaxy. The detector has been collecting data since 1992 from the cosmic ray, neutrino astrophysics, and background research programs in the underground laboratory. This talk presents a short overview of the previously obtained muon results...
The AntiCoincidence Shield of the SPectrometer on the INTEGRAL (ACS SPI) records primary and secondary HXR with energies E >100 keV. The secondary HXR is due to galactic and solar CR protons. The ACS SPI is a perfect instrument for studies of temporal relation between solar HXR flares and associated solar proton enhancements. The onset of a significant increase in the ACS SPI count rate of...
Relativistic Runaway Electron Avalanches (RREA) are central to understanding a spectrum of high-energy atmospheric phenomena, including Terrestrial Gamma-ray Flashes (TGFs), Thunderstorm Ground Enhancements (TGEs), and gamma-ray glows. Despite their common physical origin, these events are often treated separately due to differences in detection methods, duration, and altitude. In this work,...
Ground Level Enhancement (GLE) refers to a rapid increase in the intensity of cosmic particles reaching the Earth's surface, typically associated with solar flares and coronal mass ejections. This phenomenon is of significant interest due to the high energy of solar particles required to initiate secondary particles in the atmosphere that can reach sea level, subsequently increasing the...
The neutrino transport in magnetized stellar plasma of type II supernovae is considered paying particular attention for fluctuations in neutrino-nuclear scattering. These effects can be described by the Fokker-Planck equation for the neutrino phase space distribution function [1]. The respective kinetic coefficients are determined by energy transfer and straggling cross sections in neutrino...
In large-scale underwater neutrino telescopes, the geometry of the photomultiplier array constantly changes due to water currents, with individual optical modules drifting tens of meters from their initial positions. Accurate monitoring of the photomultiplier positions is indispensable to ensure stable telescope performance and maintain its angular resolution. In Baikal-GVD, the positioning of...
The muon component of extensive air showers (EAS) is widely used in the High-energy Physics as a tool for studying the processes of nucleus-nucleus interactions and secondary particle decays. Muons with energies above 100 TeV (very-high energy muons, VHE-muons) can provide information about new processes of muon generation. So the task of measuring the energy spectrum of such muons is...
Гравитационно-волновые детекторы LIGO, Virgo и KAGRA в настоящее время находятся в стадии 4-го наблюдательного периода (до октября 2025 г.). Информация о кандидатах в гравитационно-волновые события появляется на портале The General Coordinates Network (GCN). На Баксанском подземном сцинтилляционном телескопе (БПСТ) осуществляется своевременная сверка зарегистрированных мюонных нейтрино с...
It is shown that Eddington-like accretion event in the Galactic center several
million years ago and particle acceleration at accompanying shocks and jets could explain the the
observed cosmic ray spectrum at energies above 1 PeV. Cosmic ray particles are confined in extended
(several hundred kiloparsec in size) galactic halo. It is shown that the halo magnetic field could be as small...
Galactic cosmic rays up to about 100 PeV are believed to be accelerated by shock waves at supernova remnants by a Fermi process called diffusive shock acceleration (DSA). In this process, a test particle undergo a number of encounters with both inhomogeneities in the interstellar space and with shock and gain an energy.
All collisionless shock calculations should approximate particle...
Young compact clusters of massive stars contain dozens of O-, B and WR-type stars with fast powerful winds in a small ∼ pc radius. The particle acceleration by ensembles of shocks and waves of compression and rarefaction in the turbulent environment of young massive star clusters (YMSCs) is an alternative to the standard paradigm of Galactic cosmic rays acceleration on supernova shocks. In...
Based on direct numerical modeling, it is shown that pulsar wind nebulae (PWN) with a double X-ray torus are capable of accelerating very high energy protons. These objects (with well known Vela nebula as the prototype) are distinguished by a special structure of MHD flows of strongly magnetized plasma. This special structure of the nebula allows for longtime confinement of high-energy...
The GRAPES-3 experiment, located in Ooty, India, uses an array of 400 plastic scintillator detectors deployed over 25,000 m^2, and a 560 m^2 tracking muon telescope to record extensive air showers in the TeV–PeV energy range and angular muon flux above a GeV, respectively. The energy spectrum and nuclear mass composition of primary cosmic rays, solar and heliospheric phenomena, and...
Одной из основных задач исследования гамма источников с помощью атмосферных черенковских телескопов (АЧТ) является восстановление энергетического спектра испускаемых гамма квантов. В традиционном методе определения энергии гамма квантов физические характеристики восстанавливаются путем анализа параметров Хилласа, полученных из изображений ШАЛ на АЧТ и которые являются следствием статистических...
A new simulation using the CORSIKA code without accelerating coarsening of the results was performed for the energy range of 1-100 PeV, taking into account pulse formation at the input of the optical station of the TAIGA-HiSCORE array. Refined relationships between the steepness parameter of the lateral distribution function (LDF) and the light pulse FWHM at distances of 200-400 m and the...
В статье развивается метод поиска гамма- излучения от неизвестных источников над сложным астрофизическом фоном по данным установки HiSCORE в эксперименте TAIGA. Такая задача распадается на три этапа: разработка критериев выделения гамма-квантов от частиц, составляющих основной фон; выбор метода оценки и сглаживание фона; анализ статистической значимости сигнала на...
The main information about high-energy cosmic rays (above 10^15 eV) is provided by the extensive air showers (EAS), which are formed as a result of interaction of primary cosmic rays (PCR) with nuclei of atmospheric atoms. In the energy range from 10^15 to 10^17 eV, the PCR energy spectrum reconstructed by the data of EAS experiments has features which cannot be explained within the frameworks...
Recent experimental results have shown an excess of muons in extensive air showers produced by cosmic rays with energies above $10^{17}$ eV. In this work, I discuss how even small deviations from Lorentz-invariant physics could influence the interpretation of the current state of the so-called "muon puzzle."
One of the intriguing possibilities in the search for the new physics in ultra-high energy cosmic rays (UHECR) is the discovery of the Lorentz invariance violation (LIV). Several studies have investigated the consequences of the different LIV scenarios for cosmic ray physics and their influence on the measured properties of the extensive air showers (EAS). Yet, only recently, a new approach...
The TAIGA-HiSCORE EAS Cherenkov light array with total area of about 1 km^2 has collected data during the 3 seasons of observation (2021 – 2024). Reconstruction of the primary energy with Cherenkov light fluxes at the distances 100 and 200 m from the core with the adequate zenith angle corrections let us obtain the energy spectrum in the range from 300 TeV to 10 PeV. Our spectrum is in...
We present the results of a study on the mass composition of cosmic rays (CRs) in individual air shower events with energies of 0.8–2 EeV and arrival zenith angles less than 60°. The analysis utilizes extensive air showers (EAS) recorded over three observation seasons (2021–2024) by the Yakutsk EAS array following its major upgrade in 2019–2021. The CR composition was estimated by comparing...
The results of the analysis of the NEVOD-DECOR data on the study of inclined muon bundles of cosmic rays for the period from 2012 to 2023 are presented. An original method for studying the muon component of extensive air showers, local muon density spectra, was used. The data are compared with the calculations based on the simulation of air showers using the CORSIKA program for different...
Currently, the TAIGA-1 complex includes 4 Imaging Atmospheric Cherenkov Telescopes (IACT) of the TAIGA-IACT facility, 295 wide-angle Cherenkov detectors of the TAIGA-HiSCORE and Tunka-133 arrays, distributed over an area of 3 km^2, and 19 scintillation stations of the Tunka-Grande installation. With their help, a large volume of experimental data has already been obtained on the cosmic rays...
The Yakutsk EAS Array, one of the world's longest-running cosmic ray observatories, has undergone major modernization (2019–2021) to enhance its detection capabilities. Currently operating an upgraded hybrid system of scintillation and muon detectors, it provides precise measurements of extensive air showers in the 10¹⁶–10²⁰ eV range. Recent results include mass composition studies and...
The report reviews the current state of research at the multifunctional detector complex of the Tien Shan high-mountain scientific station of the Lebedev Physical Institute. The results of the search for new phenomena in the field of cosmic ray astrophysics, high-energy atmospheric physics, and geophysics are presented. In the field of cosmic ray astrophysics, the main results include the...
The accumulated problems of the high- and ultra-high energy cosmic ray physics and the tasks of the multichannel astronomy require the development of new experimental methods ensuring reliable identification of both primary and secondary cosmic ray particles.
To conduct breakthrough research in this area, the complex installations containing detectors of various types for multicomponent...
The Baikal-GVD Neutrino Telescope is a cubic-kilometer scale detector being constructed in Lake Baikal. The achievement by Baikal-GVD of the nominal sensitive volume for high-energy cascade detection of 1 km3 is expected by 2028. Currently, the Baikal collaboration is working on the development of a conceptual project of neutrino telescope in Lake Baikal with a volume about an order of...
Астрофизический комплекс TAIGA-100, площадью 100 км2 , создается для проведения исследований в области гамма-астрономии ПэВных энергий и космических лучей сверхвысоких энергий. В докладе будет представлена научная программа проекта, базовые детекторы и программа развертывания астрофизического комплекса.
One of the most challenging tasks in modern astrophysics is determining the nature and origin of cosmic rays with energies exceeding the Greisen-Zatsepin-Kuzmin (GZK) cutoff (~50 EeV), known as ultra-high-energy cosmic rays (UHECRs). The primary difficulty lies in their extremely low flux, necessitating experiments with vast exposure areas. The two largest ground-based observatories–the Pierre...
The Horizont-T installation at the Tian Shan High-Mountain Scientific Station of the Lebedev Physical Institute (LPI/FIAN), located at an altitude of 3350 meters above sea level, is designed for the detection of extensive air showers (EAS) of ultra-high energies with axis inclinations up to 70$^o$. The capabilities of the equipment allow for digitization of signals recorded by scintillation...
The SPHERE-3 setup is destined to register the EAS Cherenkov light, both the direct and the reflected from the snow surface. A set of methods and new approaches in the measurement technique enable substantial progress in the study of the primary cosmic ray composition in the energy range 1-1000 PeV. The present work reveals the current status of the project development and detector performance...
New results of modelling the operation of the new Cherenkov telescope SPHERE-3 are presented. The telescope will be able to detect cosmic particles by direct and reflected Cherenkov light of EAS. Dual detection improves the accuracy of determining the parameters of the primary particle. The study is based on the data bank of distributions of the EAS Cherenkov light obtained on the Lomonosov-2...
The source of the remarkable ultra high energy neutrino event KM3-230213A detected with the KM3-ARCA array is still not established. A persistent isotropic source hypothesis is disfavored due to the non-observation of a similar event by the larger IceCube detector that benefits from $\sim$ an order-of-magnitude larger observation time compared to the KM3-ARCA array as well.
We consider two...
We discuss the constraints on superluminal neutrino Lorentz Invariance Violation (LIV) parameters from the observation of the ultra-high-energy event KM3-230213A by the KM3NeT collaboration in cases of linear n=1 and quadratic n=2 LIV scenarios. Assuming extragalactic origin of the event, we obtain the constraints on LIV mass scale Λ_1=1.1×10^30 GeV and Λ_2=1.1×1019 GeV from the absence...
The idea that supernova remnants are a significant source of Galactic cosmic rays is supported by the fact that HESS J1731-347 would be one of the few Galactic sources to accelerate hadronic cosmic rays to TeV energy. The radius (4.2-5.5 km) and estimated mass (~ 0.77 $M_☉$) are both much less than the usual range for neutron stars. Because of its compactness and short radius, we investigate a...
The SEVAN network (Space Environment Viewing and Analysis Network), as part of the United Nations Basic Space Science (UNBSS) activities, was supported
by the International Heliophysical Year 2007 and the U Office for Outer Space Affairs. CD experts developed a new class of hybrid particle detectors capable
of measuring both neutral and charged particles. The network's initial rollout...
Igor Yashin
At present, in addition to direct observations of the Sun using space born apparatus, ground-based equipment that registers cosmic rays is widely used to monitor solar activity - neutron monitors, muon telescopes (hodoscopes) and other detectors. Neutron monitors detect neutrons from primary cosmic particles of GeV energies (~ 10 GeV), while the muon component is generated by...
At the Experimental complex NEVOD (MEPhI, Moscow), the PRISMA-36 and “Neutron” facilities are used to study variations in the neutron background. In these facilities, a detector with a thin (~30 mg/cm^2) inorganic scintillator ZnS(Ag) with LiF, where Li is enriched to 90% of 6^Li, is used to measure neutrons.
In 2024, there was a peak of solar activity, and the most powerful flares in the...
The Forbush effect is a sharp decrease in the intensity of cosmic rays caused by the deflection of charged particles by inhomogeneities in the interplanetary magnetic field. The study analyzes the Forbush effect during the geomagnetic storm of May 10-12, 2024. This storm attracted much attention from the scientific community due to its magnitude exceeding the -500 nT Sym-H index. The Sym-H...
One of the detectors for long-term observations of cosmic rays are neutron monitors (NM) which are located at different points on the planet, allowing for studies of the time, energy and angular characteristics of galactic and solar particle fluxes. Since NMs are located inside the Earth's magnetosphere, their response depends on their location on the planet's surface which can be...
An excess of extensive air showers (EAS) muons was found in several experiments at energies above 10^17 eV compared to estimates assuming even heavy composition of primary cosmic rays (PCR). Presently, the explanations for this excess are being explored, including both the potentially new physical phenomena and states of matter in EAS development, along with the efforts to modify existing...
This report presents a draft of a new detector designed to determine the chemical composition of primary cosmic rays based on the characteristics of the angular distribution of Cherenkov light from EAS. The installation, consisting of several such detectors, will be able to register individual EAS events in the energy range from 1 to 1000 PeV with high angular resolution of up to 0.3 degrees....
The origin of antiparticles -- positrons and antiprotons -- as detected by the observatories PAMELA and AMS-02 is a topical issue due to their discussed relation to the dark matter annihilations/decays. On the other hand, the observed excess of positrons can be explained by a contribution from the near-Earth pulsars once these are driving a bow shock into the interstellar medium. In this case...
The paper presents the first results of the search for ultra-high-energy gamma radiation from cosmic gamma-ray bursts based on the data from the Carpet-3 EAS array of the BNO INR RAS. The facility is located in the Baksan gorge at an altitude of 1700 m above sea level and consists of a ground-based array of and an underground muon detector with an area of 410 sq. m., which allows for the...
The brightest cosmic gamma-ray burst (GRB) ever detected, GRB~221009A, was accompanied by photons of very high energies. These gamma rays may be used to test both the astrophysical models of the burst and our understanding of long-distance propagation of energetic photons, including potential new-physics effects. Here we present the observation of a photon-like air shower with the estimated...
In the extensive air showers (EASs), photonuclear reactions transfer energy from the electromagnetic to the hadronic cascade and thus contribute to the muon production rate. However, the high-energy (center-of-momentum frame energy > 100 GeV) photonuclear cross-section is poorly constrained by laboratory experiments. This implies a systematic uncertainty in the Monte-Carlo (MC) simulations of...
The mean depth of shower is used for studying interconnection between shower longitudinal profile and hadronic interaction characteristics. The equations for the shower originated by high energy proton in the atmosphere are written and, within certain simplifications, solved for the case of logarithmically decreasing interaction length of hadrons in air.
The obtained expression explicitely...
The problem of the excess of muons in extensive air showers (EAS) from ultra-high energy cosmic rays (UHECR) in comparison to the simulation predictions, also known as the “muon puzzle”, stands as a bright signal of the incompleteness of our knowledge of high-energy cosmic ray physics. In principle, there are several ways to explain this phenomenon. One can suggest changes in the cosmic ray...
