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It is shown that the relativistic jets associated with the growth and past activity of the supermassive black hole in the Andromeda galaxy could be the main source of cosmic rays with energies above $10^{15}$ eV. Most of the cosmic ray energy is related to a bow shock of the jet that produces multi-PeV cosmic rays with light composition. The highest energy cosmic rays with heavy composition are produced in the jet itself. The spectra of energetic particles produced in Andromeda galaxy and propagated to the Earth are calculated and compared with observations., Comment: 5 pages, 4 figures, corrected references, published in MNRAS Letters

We consider diffusive shock acceleration in supernova remnants throughout their evolution including a radiative stage. It is found that a more efficient acceleration and fast exit of particles at the radiative stage results in the hardening of the source cosmic ray proton and electron spectra at energies $\sim 100-500$ GeV. The effect is stronger for cosmic ray electrons., 8 pages, 8 figures, accepted to MNRAS. arXiv admin note: text overlap with arXiv:1701.00844

A wide-angle Cerenkov array TAIGA-HiSCORE (FOV $\sim$0.6 sr), was originally created as a part of TAIGA installation for high-energy gamma-ray astronomy and cosmic ray physics. Array now consist on nearly 100 optical stations on the area of 1 km$^2$. Due to high accuracy and stability ($\sim$1 ns) of time synchronization of the optical stations the accuracy of EAS arrival direction reconstruction is reached 0.1$^\mathrm{o}$. It was proven that the array can also be used to search for nanosecond events of the optical range. The report discusses the method of searching for optical transients using the HiSCORE array and demonstrates its performance on a real example of detecting signals from an artificial Earth satellite. The search for this short flares in the HiSCORE data of the winter season 2018--2019 is carried out. One candidate for double repeater has been detected, but the estimated probability of random simulation of such a transient by background EAS events is not less than 10%, which does not allow us to say that the detected candidate corresponds to a real astrophysical transient. An upper bound on the frequency of optical spikes with flux density of more than $10^{-4} \mathrm{erg/s/cm}^2$ and a duration of more than 5\,ns is established as $\sim 2 \times 10^{-3}$ events/sr/hour., Comment: 15 pages, 6 figures, reported at the conference ISCRA-2021, Accepted for publication in Physics of Atomic Nuclei

Nonlinear model of diffusive shock acceleration is used for investigation of the particle acceleration in old supernova remnants W28 and W44. We modeled the hydrodynamical evolution of the remnants, shock modification and streaming instability produced by accelerated particles. Comparison with available radio and gamma-ray data is given., XXV ECRS 2016 Proceedings - eConf C16-09-04.3, revised version

The inverse problem of cosmic ray transport of ultra-high energy cosmic rays is considered. The analysis of Auger data on energy spectrum, energy dependence of mean logarithm of atomic mass number and its variance allows definite conclusions on the shape of the source spectrum in the frameworks of the inverse problem approach. The discussion on regularization procedure for considered ill-posed problem is presented., Comment: XXV ECRS 2016 Proceedings - eConf C16-09-04.3

It is shown that high-energy astrophysical neutrinos observed in the IceCube experiment can be produced by protons accelerated in extragalactic Type IIn supernova remnants by shocks propagating in the dense circumstellar medium. The nonlinear diffusive shock acceleration model is used for description of particle acceleration., Comment: 9 pages, 4 figures, oral talk at 34th ICRC, Hague, Netherlands 30July-06Aug 2015

A new EAS Cherenkov light array, Tunka-133, with ~1 km^2 geometrical area has been installed at the Tunka Valley (50 km from Lake Baikal) in 2009. The array permits a detailed study of cosmic ray energy spectrum and mass composition in the energy range 10^16 - 10^18 eV with a uniform method. We describe the array construction, DAQ and methods of the array calibration.The method of energy reconstruction and absolute calibration of measurements are discussed. The analysis of spatial and time structure of EAS Cherenkov light allows to estimate the depth of the EAS maximum X_max. The results on the all particles energy spectrum and the mean depth of the EAS maximum X_max vs. primary energy derived from the data of two winter seasons (2009 -- 2011), are presented. Preliminary results of joint operation of the Cherenkov array with antennas for detection of EAS radio signals are shown. Plans for future upgrades -- deployment of remote clusters, radioantennas and a scintillator detector network and a prototype of the HiSCORE gamma-telescope -- are discussed., 8 pages, Proceedings of the RICAP 2011 Conference, submitted to NIM A

The new EAS Cherenkov array Tunka-133 with about 1 km**2 geometric acceptance area is installed in the Tunka Valley (50 km from Lake Baikal). The array willpermit a detailed study of cosmic ray energy spectrum and mass composition in the energy range of 10**15 - 10**18 eV with uniform method. The array consistsof 19 clusters, each composed of 7 optical detectors with 20 cm PMTs. Since November 2008, the first 12 clusters are in operation, commissioning of the whole array is planned for September 2009 (At the time of submission of this paperto electronic arXiv(February 2010) the completed Tunka-133 array is already taking data). We describe the array construction and DAQ, preliminary results and plans for the future development: deployment of radio-antennas and muon detectors network., 4 pages, 6 figures, Proc. of 31th ICRC, July 7-15, 2009, Lodz, Poland

The final analysis of the Extensive Air Shower (EAS) maximum X_max depth distribution derived from the data of Tunka-25 atmospheric Cherenkov light array in the energy range 3.10^15 - 3.10^16 eV is presented. The perspectives of X_max studies with the new Cherenkov light array Tunka-133 of 1 km^2 area, extending the measurements up to 10^18 eV, are discussed., Comment: 6 pages, 7 figures, Proceedings of CRIS 2008 - Cosmic Ray International Seminar - Malfa, Salina Island, Eolian Islands, Italy, September 15 - 19, 2008, to be published in Nucl. Phys. B (Proc. Suppl.), 2009

The spectra of high-energy protons and nuclei accelerated by supernova remnant shocks are calculated taking into account magnetic field amplification and Alfvenic drift for different types of SNRs during their evolution. The overall energy spectrum and elemental composition of cosmic rays after propagation through the Galaxy are found., Comment: 4 pages, 4 figures, talk presented at 31st ICRC, Lodz, Poland, July 2009

The new EAS Cherenkov array Tunka-133, with about 1 km**2 sensitive area, is being installed in the Tunka Valley since the end of 2005. This array will permit a detailed study of the cosmic ray energy spectrum and the mass composition in the energy range of 10**15-10**18 eV with a unique method. The array will consist of 19 clusters, each composed of 7 optical detectors. The first cluster started operation in October 2006. We describe the data acquisition system and present preliminary results from data taken with the first cluster., 4 pages, 4 figures, Proceedings of 30th ICRC, Merinda, Mexico, July 2007

Cosmic ray acceleration in SNRs in the presence of the Alfv��nic drift is considered. It is shown that spectra of accelerated particles may be considerably softer in the presence of amplified magnetic fields., 4 pages, 4 figures, poster talk at 4-th Gamma-ray Symposium (Heidelberg, Germany, 7-11th of July 2008)

We investigate the diffusive shock acceleration in the presence of the non-resonant streaming instability introduced by Bell (2004). The numerical MHD simulations of the magnetic field amplification combined with the analytical treatment of cosmic ray acceleration permit us to calculate the maximum energy of particles accelerated by high-velocity supernova shocks. The estimates for Cas A, Kepler, SN1006, and Tycho historical supernova remnants are given. We also found that the amplified magnetic field is preferentially oriented perpendicular to the shock front downstream of the fast shock. This explains the origin of the radial magnetic fields observed in young supernova remnants., Comment: 18 pages, 9 figures, accepted to ApJ

The project of an EAS Cherenkov array in the Tunka valley/Siberia with an area of about 1 km2 is presented. The new array will have a ten times bigger area than the existing Tunka-25 array and will permit a detailed study of the cosmic ray energy spectrum and the mass composition in the energy range from 10^15 to 10^18 eV., 4 pages, 2 figures, ICRC2005, rus-kuzmichev-LA-abs1-he15-poster

The diffusion of galactic cosmic rays (CR) is considered. It is anticipated that the nonlinear MHD cascade sets the power-law spectrum of turbulence from the principle scale 100 pc to much smaller scales. We found that the dissipation of waves due to the resonant interaction with energetic particles may terminate the cascade at less than 1.e13 cm. The shape of CR diffusion coefficient that was found may explain the observed peaks of secondary to primary nuclei ratios at a few GeV/n., 4 pages, tsukuba.sty, to appear in the Proc. 28th International Cosmic Ray Conference (Tsukuba, Japan 2003)

The instability in the cosmic-ray (CR) precursor of a SN shock is studied. The level of turbulence in this region determines the maximum energy of accelerated CRs. The consideration is not limited by the case of weak turbulence. It is assumed that Kolmogorov type nonlinear wave interactions together with the ion-neutral collisions restrict the amplitude of random magnetic field. As a result, the maximum energy of accelerated particles strongly depends on the age of a SNR. It can be as high as $10^{17}Z$ eV in young SNR and falls down to about $10^{10}Z$ eV at the end of Sedov stage ($Z$ is the particle charge). This finding may explain why the SNRs with the age more than a few thousand years are not prominent sources of very high energy $\gamma $-rays. The averaged spectrum of ultrarelativistic CR injected in the interstellar medium is close or somewhat steeper than $E^{-2}$., Comment: 4 pages, 1 figure

Nonlinear damping of parallel propagating Alfv��n waves in high-$��$ plasma is considered. Trapping of thermal ions and Coulomb collisions are taken into account. Saturated damping rate is calculated. Applications are made for cosmic ray propagation in the Galaxy., 4 pages, LaTeX, published in Proc. 26th ICRC