Tunka-133: Results of 3 year operation Prosin, V.V.; Berezhnev, S.F.; Budnev, N.M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2014, Letnik:
756
Journal Article
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The EAS Cherenkov light array Tunka-133, with ~3km2 geometric area, is taking data since 2009. The array permits a detailed study of cosmic ray energy spectrum and mass composition in the PeV energy ...range. After a short description of the methods of EAS parameter reconstruction, we present the all-particle energy spectrum and results of studying CR composition, based on 3 seasons of array operation. In the last part of the paper, we discuss possible interpretations of the obtained results.
This paper proposes a qualitative and quantitative solution of a long-standing problem in astrophysics: the origin of the knee in the Galactic cosmic ray (GCR) spectrum. We calculate GCR flux ...averaged over Supernova explosion energies and types, applying only the formulae of the standard model of CR acceleration in Supernova remnants (SNR) and the latest astronomical data on the variety in Supernovae. For this purpose we estimate the distribution of SNe in explosion energies and show this distribution to be probably a very asymmetric function with large dispersion. In the case under consideration the cosmic ray flux in the whole energy range should be predominantly formed by the most energetic SN explosions. The knee in the GCR spectrum at energy around $E_{\rm knee}=3$ PeV can quantitatively be explained by the dominant contribution of Hypernovae. The model sketches the all-particle cosmic ray spectrum up to 1018 eV.
The Tunka-133 EAS Cherenkov light array: Status of 2011 Berezhnev, S.F.; Besson, D.; Budnev, N.M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2012, Letnik:
692
Journal Article
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A new EAS Cherenkov light array, Tunka-133, with ∼1km2 geometrical area has been installed at the Tunka Valley (50km from Lake Baikal) in 2009. The array permits a detailed study of cosmic ray energy ...spectrum and mass composition in the energy range 1016–1018eV 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 Xmax.
The results on the all particles energy spectrum and the mean depth of the EAS maximum Xmax 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 the 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.
•Model +7 with a large dispersion of CR maximum energy accelerated in SNRs of different types is studied.•List of potential nearby and young CR sources is compiled and their role in CR fluxes is ...investigated.•Experimental procedure of ‘two-dimensional’ anisotropy measurements is reproduced.•A fine structures of CR spectrum and general features of dipole anisotropy are explained.•Indication of the SNRs thatcan be responsible for the knee origin.
The role of nearby galactic sources, the supernova remnants, in formation of observed energy spectrum and large-scale anisotropy of high-energy cosmic rays is studied. The list of these sources is made up based on radio, X-ray and gamma-ray catalogues. The distant sources are treated statistically as ensemble of sources with random positions and ages. The source spectra are defined based on the modern theory of cosmic ray acceleration in supernova remnants while the propagation of cosmic rays in the interstellar medium is described in the frameworks of galactic diffusion model. Calculations of dipole component of anisotropy are made to reproduce the experimental procedure of “two-dimensional” anisotropy measurements. The energy dependence of particle escape time in the process of acceleration in supernova remnants and the arm structure of sources defining the significant features of anisotropy are also taken into account. The essential new trait of the model is a decreasing number of core collapse SNRs being able to accelerate cosmic rays up to the given energy, that leads to steeper total cosmic ray source spectrum in comparison with the individual source spectrum. We explained simultaneously the new cosmic ray data on the fine structure of all particle spectrum around the knee and the amplitude and direction of the dipole component of anisotropy in the wide energy range 1TeV–1EeV. Suggested assumptions do not look exotic, and they confirm the modern understanding of cosmic ray origin.
Some results of studies of cosmic rays obtained during the NUCLEON space experiment in 2015–2017 are presented. This experiment was intended for direct measurements of the energy spectra and chemical ...composition of cosmic rays (
Z
= 1−30) in the energy range 2–500 TeV. Results presented include energy spectra for various abundant nuclei measured using the new Kinematic Lightweight Energy Meter (KLEM). The primary energies are established using the spatial densities of secondary particles produced in inelastic interactions with a carbon target.
This work is a methodical study of another option of the hybrid method originally aimed at gamma/hadron separation in the TAIGA experiment. In the present paper this technique was performed to ...distinguish between different mass groups of cosmic rays in the energy range 200 TeV - 500 TeV. The study was based on simulation data of TAIGA prototype and included analysis of geometrical form of images produced by different nuclei in the IACT simulation as well as shower core parameters reconstructed using timing array simulation. We show that the hybrid method can be sufficiently effective to precisely distinguish between mass groups of cosmic rays.
This work is a methodical study on hybrid reconstruction techniques for hybrid imaging/timing Cherenkov observations. This type of hybrid array is to be realized at the gamma-observatory TAIGA ...intended for very high energy gamma-ray astronomy (> 30 TeV). It aims at combining the cost-effective timing-array technique with imaging telescopes. Hybrid operation of both of these techniques can lead to a relatively cheap way of development of a large area array. The joint approach of gamma event selection was investigated on both types of simulated data: the image parameters from the telescopes, and the shower parameters reconstructed from the timing array. The optimal set of imaging parameters and shower parameters to be combined is revealed. The cosmic ray background suppression factor depending on distance and energy is calculated. The optimal selection technique leads to cosmic ray background suppression of about 2 orders of magnitude on distances up to 450 m for energies greater than 50 TeV.
The EAS Cherenkov light array Tunka-133, with ~ 3 km2 geometric area, is taking data since 2009.The array permits a detailed study of energy spectrum and mass composition of cosmic rays in the ...energy range from 6 · 1015 to 1018 eV. We describe the methods of time and amplitude calibration of the array and the methods of EAS parameters reconstruction. We present the all-particle energy spectrum, based on 7 seasons of operation.
A 'knee-like' approximation of Cherenkov light Lateral Distribution Functions, which we developed earlier, now is used for the actual tasks of background rejection methods for high energy (tens and ...hundreds of TeV) gamma-ray astronomy. In this work we implement this technique to the HiSCORE wide angle timing array consisting of Cherenkov light detectors with spacing of 100 m covering 0.2 km2 presently and up to 5 km2 in future. However, it can be applied to other similar arrays. We also show that the application of a multivariable approach (where 3 parameters of the knee-like approximation are used) allows us to reach a high level of background rejection, but it strongly depends on the number of hit detectors.
On leaky-box approximation to GALPROP Ptuskin, V.S.; Strelnikova, O.N.; Sveshnikova, L.G.
Astroparticle physics,
05/2009, Letnik:
31, Številka:
4
Journal Article
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The Galactic Propagation (GALPROP) numerical code is now accepted as an advanced tool for simulations of cosmic-ray diffusion and interaction in the Galaxy. The code is used for the interpretation of ...a large body of cosmic-ray data. In some cases, including in particular the case of stable primary and secondary nuclei, one can use a simple leaky-box model for handling of data on cosmic-ray energy spectra and composition. We find an adequate leaky-box approximation to the basic GALPROP model and estimate its accuracy.
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