We present an improved method for the precise reconstruction of cosmic-ray air showers above 1017 eV with sparse radio arrays. The method is based on the comparison of measured pulses to predictions ...for radio pulse shapes by CoREAS simulations. We applied our method to the data of Tunka-Rex, a 1 km2 radio array in Siberia operating in the frequency band of 30–80 MHz. Tunka-Rex is triggered by the air-Cherenkov detector Tunka-133 and by scintillators (Tunka-Grande). The instrument collects air-shower data since 2012. The present paper describes an updated data analysis of Tunka-Rex and details of the new method applied. After quality cuts, when Tunka-Rex reaches its full efficiency, the energy resolution of about 10% given by the new method has reached the limit of systematic uncertainties due to the calibration uncertainty and shower-to-shower fluctuations. At the same time the shower maximum reconstruction has improved compared to the previous method based on the slope of the lateral distribution and reaches a precision of better than 35 g/cm2. We also define conditions of the measurements at which the shower maximum resolution of Tunka-Rex reaches a value of 25 g/cm2 and becomes competitive to optical detectors. To check and validate our reconstruction and efficiency cuts we compare individual events to the reconstruction of Tunka-133. Furthermore, we compare the mean of the shower maximum as a function of primary energy to the measurements of other experiments.
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.
The TAIGA observatory addresses ground-based gamma-ray astronomy at energies from a few TeV to several PeV, cosmic ray physics from 100 TeV to several EeV as well as for search for axion-like ...particles, Lorentz violations and another evidence of New Physics. In 2020 year a one square kilometer TAIGA setup should be put in operation.
The status of the TAIGA experiment (Tunka Advanced Instrument for cosmic-ray physics and Gamma-ray Astronomy) located in the Tunka Valley is presented. The paper presents mainly the tasks, developed ...approaches for their solution, and first results on high-energy gamma-ray astronomy (10 TeV and higher) obtained from a two- to three-year exposure. The current tasks of gamma-ray astronomy and plans for development of the installation are discussed.
In November 2020, the IceCube Neutrino Observatory registered a neutrino event with an energy of 150 TeV directed at the Cygnus Cocoon gamma-ray source. In the Carpet-2 experiment, as part of the ...Baksan Neutrino Observatory (BNO), a sharp increase in the flow of events with an energy above 300 TeV was recorded from the same direction within the angular accuracy of the events. This flux is 4 orders of magnitude higher than the expected intensity of gamma quanta of this energy region according to data in the region of less than 100 TeV. It was expected that such a powerful flare could be registered by the TAIGA-HiSCORE installation of the TAIGA astrophysical complex. We analyzed the events of the EAS recorded by the installation of TAIGA-HiSCORE for 18 h in October–November 2020 from the Cygnus Cocoon source. This article provides the upper limit of the expected excess flow.
The TAIGA gamma observatory is continuing its deployment at the Tunka valley, close to lake Baikal. The new, original detectors, able to work under severe conditions of Siberia, were developed to ...increase the TAIGA sensitivity for the study of gamma-quanta at energies about 1 PeV and above. The distinguishing feature of the detectors is the use of the wavelength shifting light guides for scintillation light collection on a photodetector. Several designs of the counters have been tested: equipped with PMT or SiPM photo-detectors, acrylic or polystyrene based scintillators with thickness from 1 to 5 cm and detecting area from 0.75 to 1.0 m
2
. The data on the amplitude of the signal from cosmic muons measured in different points within the counter are presented. The first 48 counters were produced and deployed in 2019 at the TAIGA experiment. They form 3 stations each with 8 surface detectors and 8 underground detectors buried at the depth of 1.7 m. After two winters, all counters are working.
The physical motivations and performance of the TAIGA (Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy) project are presented. The TAIGA observatory addresses ground-based ...gamma-ray astronomy at energies from a few TeV to several PeV, as well as cosmic ray physics from 100 TeV to several EeV and astroparticle physics. The pilot TAIGA-1 complex locates in the Tunka valley,
km West from the southern tip of the lake Baikal. It includes integrated air Cherenkov TAIGA-HiSCORE array with 120 wide-angle optical stations distributed over on area 1.1 square kilometer about and three 4-m class Imaging Atmospheric Cherenkov Telescopes of the TAIGA-IACT array. The latter array has a shape of triangle with side lengths of about 300, 400 and 500 m. The integral sensitivity of the 1-km
TAIGA-1 detector is about
TeV cm
s
for detection of
TeV gamma-rays in 300 hours of source observations. The combination of the wide-angle Cherenkov array and IACTs could offer a cost effective-way to build a large (up to 10 km
) array for very high energy gamma-ray astronomy. The reconstruction of a given EAS energy, incoming direction, and the core position, based on the TAIGA-HiSCORE data, allows one to increase the distance between the relatively expensive IACTs up to 600–800 m. These, together with the surface and underground electron/Muon detectors, will be used for selection of gamma-ray-induced EAS. Present status of the project, together with the current array description, the first experimental results and plans for the future are reported.
This paper presents the results of an analysis of observations of the Crab Nebula gamma-ray source with the first two atmospheric Cherenkov telescopes of the TAIGA (Tunka Advanced Instrument for ...cosmic ray physics and Gamma Astronomy) astrophysical complex in the stereo mode of observations. The article analyzed observational data from 2020 to 2021. Over 36 hours of observations, a signal was obtained at a statistical significance level of 5
and a spectrum of gamma rays was plotted in the energy range from 2 to 70 TeV. The paper describes a technique for gamma–hadron separation and reconstruction of detected gamma-rays energy.
A scintillation experiment is a part of the TAIGA astrophysical complex located in the Tunka Valley, 50 km from Lake Baikal. It consists of the Tunka-Grande and TAIGA-Muon arrays. Its scientific ...program is devoted to the study of cosmic rays (CRs) and search for astrophysical gamma rays by detecting charged particles (electrons and muons) of extensive air showers (EASs). We present the current status of the scintillation experiment, methods of EAS and CR parameters’ reconstruction, the main results obtained by the Tunka-Grande array and our scientific program for the future.
The current status of the equipment development for the new wide-angle gamma-ray imaging air Cherenkov telescope for TAIGA hybrid installation is presented. A front-end electronic and data ...acquisition system board based on the Zynq family Xilinx FPGA chips specially designed for this project have been produced and are being tested. A detailed description if presented for internal structure of the four main subsystems: four 8-channel 100 MHz ADCs, board’s control system, internal clock and synchronization system and the power supply system. Additionally, the current status of a small scale prototype telescope SIT consisting of 49 SiPM is presented. The telescope includes a digital camera for observing the stars and weather condition. The SIT-HiSCORE synchronization systems and the telemetry information collection had been tested.