arXiv subjects

A. D. Krasilnikov

Publications and source records attributed to A. D. Krasilnikov.

9 recordsLinked to original sources

arXiv2025

Giant Atmospheric Showers Detected by the Yakutsk Extensive Air Shower Array

The two most powerful extensive air showers (EAS) with energies of about $10^{20}$ eV, registered at the Yakutsk EAS array during the entire observation period of 1974-2024, are considered. Both showers hit the array near the center and triggered all surface detectors and underground muon detectors with a threshold energy of $E_μ = 1.0 \times \cos θ$ GeV. These events have an abnormally high fraction of muons, which is beyond current model predictions. This may change our understanding of hadron interactions at ultra-high energy, but there is also a possibility that these showers were initiated by some exotic primary particles.

astro-ph.HE↗

arXiv2021

Status of the Yakutsk air shower array and future plans

The Yakutsk Extensive Air Shower Array has been continuously operating for more than 50 years (since 1970) and up until recently it has been one of world's largest ground-based instruments aimed at studying the properties of cosmic rays in the ultra-high energy domain. In this report we discuss results recently obtained at the array - on cosmic rays energy spectrum, mass composition and directional anisotropy - and how they fit into the world data. Special attention is paid to the measurements of muonic component of extensive air showers. Theoretical results of particle acceleration at shocks are also briefly reviewed. Future scientific and engineering plans on the array modernization are discussed.

astro-ph.IM↗

arXiv2018

A beam of ultrahigh energy particles of the same magnetic rigidity

Two EAS arrays during a day have recorded 3 particles with energies above 30 EeV arriving from the same sky region. Two events were registered by the Yakutsk array and one - by the Telescope Array. Two Yakutsk events were estimated to be same energy and the Telescope Array shower's energy was almost 2 times higher. This indicates the same magnetic rigidity of all three particles, if the charge differs by a factor of 2. The relatively short sequence of all three events and their "monochromaticity" in rigidity can be due to the magnetic separation of particles in the acceleration process and propagation of the beam.

astro-ph.HE↗

arXiv2014

Wide field-of-view Cherenkov telescope for the detection of cosmic rays in coincidence with the Yakutsk extensive air shower array

The Yakutsk array group is developing a wide field-of-view Cherenkov telescope to be operated in coincidence with the surface detectors of the extensive air shower array. Currently, the engineering prototype of the reflecting telescope with the front-end electronics is designed, assembled, and tested to demonstrate the feasibility of the conceived instrument. The status and specifications of the prototype telescope are presented, as well as the modernization program of the already existing Cherenkov light detectors subset of the array measuring ultra-high energy cosmic rays.

astro-ph.IM↗

arXiv2014

Large-scale distribution of cosmic rays in right ascension as observed by the Yakutsk array at energies above $10^{18}$ eV

We present the results of searches for anisotropy in the right ascension ($RA$) distribution of arrival directions of cosmic rays (CRs) detected with the Yakutsk array during the 1974--2008 observational period in the energy range above $10^{18}$ eV. Two methods of analysis are applied to two sub-samples of the data. Particularly, estimations of the first and second harmonic amplitudes are given, as well as the first harmonic phase in adjacent energy intervals. Analysis of variance demonstrates a significant contraction of the minimal width of the $RA$ distribution in the energy bin $(10^{19},1.78\times10^{19})$ eV with respect to the isotropic distribution, which may be attributed to a possible source of CRs within the interval $RA\in(15^0,45^0)$.

astro-ph.HE↗

arXiv2004

Cosmic Rays with Energy Above 10^{17} ev

The energy spectrum of primary cosmic rays with ultra high energies based on the Yakutsk EAS Array data is presented. For the largest events values of S600 and axis coordinates have been obtained using revised lateral distribution function. The affect of the arrival time distribution at several axis distance on estimated density for Yakutsk and AGASA is considered.

astro-ph↗

arXiv2004

Spectrum of cosmic rays with energy above $10^{17}$ eV

There are some discrepancies in the results on energy spectrum from Yakutsk, AGASA, and HiRes experiments. In this work differential energy spectrum of primary cosmic rays based on the Yakutsk EAS Array data is presented. For the largest events values of $S_{600}$ and axes coordinates have been obtained using revised lateral distribution function. Simulation of converter's response at large distances showed no considerable underestimation of particle density. Complex shape of spectrum in region of $\E > 10^{17}$ eV is confirmed. After adjustment of parameters and additional exposition at the Yakutsk array there are three events with energy $\E > 10^{20}$ eV.

astro-ph↗

arXiv2004

The spectrum features of UHECRs below and surrounding GZK

The energy spectrum of UHECRs is discussed on the basis of the Yakutsk array database analysis. In the region E=0.1 to 30 EeV the showers are detected under trigger-500, while at energies above 30 EeV the whole acceptance area for trigger-1000 is used in order to utilize all the data available in the region of GZK cutoff.

astro-ph↗

arXiv1999

Azimuthal modulation of the event rate of cosmic ray extensive air showers by the geomagnetic field

The Earth's magnetic field effect on the azimuthal distribution of extensive air showers (EAS) of cosmic rays has been evaluated using a bulk of the Yakutsk array data. The uniform azimuthal distribution of the EAS event rate is rejected at the significance level 10^(-14). Amplitude of the first harmonics of observed distribution depends on zenith angle as A1=0.2*sin^2(theta) and is almost independent of the primary energy; the phase coincides with the magnetic meridian. Basing upon the value of measured effect, the correction factor has been derived for the particle density depending on a geomagnetic parameter of a shower.

astro-ph↗