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One of the most informative accounts of the past of the Karaite communities in the Crimea are the documents related to the regulation of marriage and family relations among the Karaites. Although the Russian authorities integrated the Karaites into the Russian linguistic and cultural space, the communal norms and tenets of the Karaite religion remained unchanged to the second half of the nineteenth century. In the sphere of matrimonial relations, the Karaites were guided by the teachings formulated in the works of the Karaite religious authorities of the Middle Ages and the commentaries to these works by authors from the Modern Period. The Karaite clergy carefully monitored the accuracy of religious rites, the observance of religious canons and the norms of family law. This article examines private legal documents, or Karaite marriage contracts shetar, signed between the representatives of Karaite communities of the Russian Empire, as well as the accompanying materials, which accompanied the process of documenting marital and family relations of the Karaites. Particularly, the author has analysed the peculiarities of their design and structure, as well as the main trends that influenced the transformation of their content, production, and appearance.

The realtime follow-up of neutrino events is a promising approach to search for astrophysical neutrino sources. It has so far provided compelling evidence for a neutrino point source: the flaring gamma-ray blazar TXS 0506+056 observed in coincidence with the high-energy neutrino IceCube-170922A detected by IceCube. The detection of very-high-energy gamma rays (VHE, $\mathrm{E} > 100\,\mathrm{GeV}$) from this source helped establish the coincidence and constrained the modeling of the blazar emission at the time of the IceCube event. The four major imaging atmospheric Cherenkov telescope arrays (IACTs) - FACT, H.E.S.S., MAGIC, and VERITAS - operate an active follow-up program of target-of-opportunity observations of neutrino alerts sent by IceCube. This program has two main components. One are the observations of known gamma-ray sources around which a cluster of candidate neutrino events has been identified by IceCube (Gamma-ray Follow-Up, GFU). Second one is the follow-up of single high-energy neutrino candidate events of potential astrophysical origin such as IceCube-170922A. GFU has been recently upgraded by IceCube in collaboration with the IACT groups. We present here recent results from the IACT follow-up programs of IceCube neutrino alerts and a description of the upgraded IceCube GFU system., Presented at the 37th International Cosmic Ray Conference (ICRC 2021). See arXiv:2107.06966 for all IceCube contributions. See arXiv:2108.05257 for all H.E.S.S. contributions

The conditions for obtaining high-quality heavily doped epitaxial Ge:P/Si(001) epitaxial layers by hot wire chemical vapor deposition were determined. The thermal decomposition of GaP was employed to provide the source of P. Extremely high electron concentration in Ge layers (up to 1.3×1020 cm−3) were achieved. According to the secondary ion mass spectroscopy data, the P concentration was constant within the entire thickness of the Ge layers and drops down abruptly at the boundary with the Si buffer. A strong direct bandgap edge photoluminescence line has been observed from the heavily doped n+-Ge:P layers at room temperature.

The supernova remnant LMC N132D is a remarkably luminous gamma-ray emitter at $\sim$50 kpc with an age of $\sim$2500 years. It belongs to the small group of oxygen-rich SNRs, which includes Cassiopeia A (Cas A) and Puppis A. N132D is interacting with a nearby molecular cloud. By adding 102 hours of new observations with the High Energy Stereoscopic System (H.E.S.S.) to the previously published data with exposure time of 150 hours, we achieve the significant detection of N132D at a 5.7$\sigma$ level in the very high energy (VHE) domain. The gamma-ray spectrum is compatible with a single power law extending above 10 TeV. We set a lower limit on an exponential cutoff energy at 8 TeV with 95% CL. The multi-wavelength study supports a hadronic origin of VHE gamma-ray emission indicating the presence of sub-PeV cosmic-ray protons. The detection of N132D is remarkable since the TeV luminosity is higher than that of Cas A by more than an order of magnitude. Its luminosity is comparable to, or even exceeding the luminosity of RX J1713.7-3946 or HESS J1640-465. Moreover, the extended power-law tail in the VHE spectrum of N132D is surprising given both the exponential cutoff at 3.5 TeV in the spectrum of its 340-year-old sibling, Cassiopeia A, and the lack of TeV emission from a Fermi- LAT 2FHL source (E > 50 GeV) associated with Puppis A. We discuss a physical scenario leading to the enhancement of TeV emission via the interaction between N132D and a near molecular cloud., Comment: Presented at the 37th International Cosmic Ray Conference (ICRC 2021) on behalf of the H.E.S.S. collaboration

Since 1996 the blast wave driven by SN 1987A has been interacting with the dense circumstellar material, which provides us with a unique opportunity to study the early evolution of a newborn supernova remnant (SNR). Based on the XMM-Newton RGS and EPIC-pn X-ray observations from 2007 to 2019, we investigated the post-impact evolution of the X-ray emitting gas in SNR 1987A. The hot plasma is represented by two non-equilibrium ionization components with temperature of $\sim0.6$ keV and $\sim2.5$ keV. The low-temperature plasma has a density $\sim2400$ cm$^{-3}$, which is likely dominated by the lower density gas inside the equatorial ring (ER). The high-temperature plasma with a density $\sim550$ cm$^{-3}$ could be dominated by the H II region and the high-latitude material beyond the ring. In the last few years, the emission measure of the low-temperature plasma has been decreasing, indicating that the blast wave has left the main ER. But the blast wave is still propagating into the high-latitude gas, resulting in the steadily increase of the high-temperature emission measure. In the meantime, the average abundances of N, O, Ne, and Mg are found to be declining, which may reflect the different chemical compositions between two plasma components. We also detected the Fe K lines in most of the observations, showing increasing flux and centroid energy. We interpret the Fe K lines as from a third hot component, which may come from the reflected shock-heated gas or originate from Fe-rich ejecta clumps, shocked by the reverse shock., Comment: 33 pages, 10 figures, accepted for publication in ApJ

The Circinus galaxy is a composite starburst/Seyfert galaxy which exhibits radio lobes inflated by kpc scale outflows along its minor axis. Its proximity (4 Mpc) makes it a unique target to study the physical nature of these outflows. We investigate if they originate from nuclear star formation activity or if they are jets from an active galactic core. The MeerKAT array performs 5 arcsecond resolution radio observations, which is in the observed range of the arcminute lobes of the Circinus galaxy. In this work, a multi-wavelength analysis of the radio lobe structures will be conducted using the available MeerKAT observations and Fermi-LAT data, which will aid in the understanding of the origin of these structures. The results can then be compared to the star-formation driven Fermi bubbles in the Milky Way, which have also been observed in both the gamma-ray and the radio bands to determine possible physical similarities between these structures.

The aim of the offered article is an analysis of legal and religious aspects of marriage-domestic relations, and demographic statistics in the Karaite’s communities of the Russian Empire in the end of the 19th and Early 20th century. In particular, in the article author has describes the activity of confessional self-government bodies and the organizational problems of the religious life of Karaite communities. This institution was the main authority for resolving issues related to the observance of the doctrines of the Karaite religion; spiritual government made judgments on the regulation of family and marriage relations in Karaite society, including the issue of interfaith and interethnic marriages.

High-resolution imaging of the Sunyaev–Zel'dovich (SZ) effect opens new possibilities for testing the presence of various high-energy particle populations in clusters of galaxies. A detailed X-ray analysis of the ‘Bullet cluster’ (1E 0657−56) with Chandra has revealed the presence of additional X-ray spectral components beyond a simple, single-temperature plasma in its X-ray spectra. X-ray methods alone are insufficient to elucidate the origins of these spectral components. We show that the morphology and magnitude of the SZ effect at high frequencies are critically dependent upon the mechanism by which the additional X-ray spectra are created. We examine the differences between the predicted SZ effect emission maps at 600 GHz assuming the X-ray spectra are composed of thermal gas with a steep power-law index component and also thermal gas with a significant contribution of strongly heated gas. A two-temperature model with a hot (kT ≃ 30–40 keV) second component is the most consistent with existing SZ data at high frequencies. However, significant morphological differences remain. High-angular-resolution SZ intensity maps at high frequencies in combination with deep X-ray data provide a new window into understanding particle energization processes in the hottest, massive merging galaxy clusters.

We perform relativistic hydrodynamic simulations of the formation and evolution of AGN cocoons produced by very light powerful jets. We calculate the intensity maps of the Sunyaev-Zel'dovich (SZ) effect at high frequencies for the simulated AGN cocoons using the relativistically correct Wright formalism. Our fully relativistic calculations demonstrate that the contribution from the high temperature gas (kb Te ~ 100 keV) to the SZ signal from AGN cocoons at high frequencies is stronger than that from the shocked ambient intercluster medium owing to the fact that the relativistic spectral functions peak at these temperature values. We present simulations of the SZ effect from AGN cocoons at various frequencies, and demonstrate that SZ observations at 217 GHz and at higher frequencies, such as 857 GHz, will provide us with knowledge about the dynamically-dominant component of AGN cocoons.

Clusters of galaxies are mainly formed by merging of smaller structures, according to the standard cosmological scenario. If the mass of a substructure is greater than or similar to 10 per cent of that of a galaxy cluster, the temperature distribution of the intracluster medium (ICM) in a merging cluster becomes inhomogeneous. Various methods have been used to derive the two-dimensional projected temperature distribution of the ICM. However, methods for studying temperature distribution along the line of sight through the cluster were absent. In this Letter, we present the first measurement of the temperature standard deviation along the line of sight, using as a reference case the multifrequency Sunyaev-Zel'dovich measurements of the Bullet Cluster. We find that the value of the temperature standard deviation is high and equals to (10.6 +/- 3.8) keV in the Bullet Cluster. This result shows that the temperature distribution in the Bullet Cluster is strongly inhomogeneous along the line of sight and provides a new method for studying galaxy clusters in depth.

The article analyses the development of Crimean studies from the end of the 18th century until today. It is only after the Russian annexation of the Crimea that the scholars started seriously studying the Crimean peninsula, its history, ethnography, geography, and other disciplines. At the end of the 18th and early 19th centuries the historico-ethnographic information was collected largely by state officials and travelling scientists of non-Russian origin. In the first half of the 19th century the Crimea was already studied by professional ethnographers and historians; it is in this period that the museums of antiquities were established in Kerch and Theodosia. A major wave of interest in the Crimea in Russia and in Europe took place as a consequence of the Crimean war in the 1850s. In the second half of the 19th century the Crimea continued to be studied by professional scholars; a special organisation TUAK was established to control the state of the Crimean antiquities. The study of the Crimea by Soviet...

The Sunyaev-Zel'dovich (hereafter SZ) effect is a promising tool to derive the gas temperature of galaxy clusters. The approximation of a spherically symmetric gas distribution is usually used to determine the temperature structure of galaxy clusters, but this approximation cannot properly describe merging galaxy clusters. The methods used so far, which do not assume the spherically symmetric distribution, permit us to derive 2D temperature maps of merging galaxy clusters. In this paper, we propose a method to derive the standard temperature deviation and temperature variance along the line-of-sight, which permits us to analyze the 3D temperature structure of galaxy clusters by means of the thermal SZ effect. We also propose a method to reveal merger shock waves in galaxy clusters by analyzing the presence of temperature inhomogeneities along the line-of-sight.

Spectral line emissivities have usually been calculated for a Maxwellian electron distribution. But many theoretical works on galaxy groups and clusters and on the solar corona suggest to consider modified Maxwellian electron distribution functions to fit observed X-ray spectra. Here we examine the influence of high energy electron populations on measurements of metal abundances. A generalized approach which was proposed in the paper by Prokhorov et al. (2009) is used to calculate the line emissivities for a modified Maxwellian distribution. We study metal abundances in galaxy groups and clusters where hard X-ray excess emission was observed. We found that for modified Maxwellian distributions the argon abundance decreases for the HCG 62 group, the iron abundance decreases for the Centaurus cluster and the oxygen abundance decreases for the solar corona with respect to the case of a Maxwellian distribution. Therefore, metal abundance measurements are a promising tool to test the presence of high energy electron populations., 6 pages, 4 figures, accepted for publication in A&A

The cluster baryon fraction is estimated from the CMB-scattering leptonic component of the intracluster medium (ICM); however, the observed cluster baryon fraction is less than the cosmic one. Understanding the origin of this discrepancy is necessary for correctly describing the structure of the ICM. We estimate the baryonic mass in the outskirts of galaxy clusters which is difficult to observe because of low electron temperature and density in these regions. The time scale for the electrons and protons to reach equipartition in the outskirts is longer than the cluster age. Since thermal equilibrium is not achieved, a significant fraction of the ICM baryons may be hidden in shells around galaxy clusters. We derive the necessary condition on the cluster mass for the concealment of missing baryons in an outer baryon shell and show that this condition is fulfilled because cluster masses are comparable to the estimated characteristic mass $M=e^4/(m^3_{p} G^2)=1.3x10^{15}$ solar masses. The existence of extreme-ultraviolet emission haloes around galaxy clusters is predicted., 6 pages, 4 figures, A&A in press

The stochastic acceleration of subrelativistic electrons from a background plasma is studied in order to find a possible explanation of the hard X-ray (HXR) emission detected from the Coma cluster. We calculate the necessary energy supply as a function of the plasma temperature and of the electron energy. We show that, for the same value of the HXR flux, the energy supply changes gradually from its high value (when emitting particle are non-thermal) to lower values (when the electrons are thermal). The kinetic equations we use include terms describing particle thermalization as well as momentum diffusion due to the Fermi II acceleration. We show that the temporal evolution of the particle distribution function has, at its final stationary stage, a rather specific form: it cannot be described by simple exponential or power-law expressions. A broad transfer region is formed by Coulomb collisions at energies between the Maxwellian and power-law parts of the distribution function. In this region the radiative lifetime of a single electron differs greatly from the lifetime of the distribution function as a whole. For a plasma temperature of 8 keV, the particles emitting bremsstrahlung at 20-80 keV lie in this quasi-thermal regime. We show that the energy supply required by quasi-thermal electrons to produce the observed HXR flux from Coma is one or two orders of magnitude smaller than the value derived from the assumption of a nonthermal origin of the emitting particles. This result may solve the problem of rapid cluster overheating by nonthermal electrons. We finally predict the change in Coma's SZ effect caused by the distortions of the Maxwellian electron spectrum, and we show that evidence for acceleration of subrelativistic electrons can be derived from detailed spectral measurements., Comment: 14 pages, 11 figures, A&A in press

We propose a morphological analysis for searches of extended gamma-ray emission associated with dark matter annihilation. Our approach is based on the likelihood analysis including the spatial templates produced by taking into account the residual count maps in the energy band where the dark matter annihilation spectrum has a prominent spectral feature. The approach is tested on the example of the possible dark matter annihilation signal from the Virgo cluster of galaxies.

High-frequency, high-resolution imaging of the Sunyaev-Zel'dovich (SZ) effect is an important technique to study the complex structures of the atmospheres of merging galaxy clusters. Such observations are sensitive to the details of the electron spectrum. We show that the morphology of the SZ intensity maps in simulated galaxy clusters observed at 345 GHz, 600 GHz, and 857 GHz are significantly different because of SZ relativistic corrections. These differences can be revealed by high-resolution imaging instruments. We calculate relativistically corrected SZ intensity maps of a simulated, massive, merging galaxy cluster and of the massive, merging clusters 1E0657-558 (the Bullet Cluster) and Abell 2219. The morphologies of the SZ intensity maps are remarkably different between 345 GHz and 857 GHz for each merging cluster. We show that high-resolution imaging observations of the SZ intensity maps at these frequencies, obtainable with the LABOCA and HERSCHEL-SPIRE instruments, allow to fully exploit the astrophysical relevance of the predicted SZ morphological effect.

Measurements of the Sunyaev-Zel'dovich (hereafter SZ) effect distortion of the cosmic microwave background provide methods to derive the gas pressure and temperature of galaxy clusters. Here we study the ability of SZ effect observations to derive the electron distribution function (DF) in massive galaxy clusters. Our calculations of the SZ effect include relativistic corrections considered within the framework of the Wright formalism and use a decomposition technique of electron DFs into Fourier series. Using multi-frequency measurements of the SZ effect, we find the solution of a linear system of equations that is used to derive the Fourier coefficients; we further analyze different frequency samples to decrease uncertainties in Fourier coefficient estimations. We propose a method to derive DFs of electrons using SZ multi-frequency observations of massive galaxy clusters. We found that the best frequency sample to derive an electron DF includes high frequencies $\nu$=375, 600, 700, 857 GHz. We show that it is possible to distinguish a Juttner DF from a Maxwell-Bolzman DF as well as from a Juttner DF with the second electron population by means of SZ observations for the best frequency sample if the precision of SZ intensity measurements is less than 0.1%. We demonstrate by means of 3D hydrodynamic numerical simulations of a hot merging galaxy cluster that the morphologies of SZ intensity maps are different for frequencies $\nu$=375, 600, 700, 857 GHz. We stress that measurements of SZ intensities at these frequencies are a promising tool for studying electron distribution functions in galaxy clusters., Comment: 11 pages, 12 figures, published in Astronomy and Astrophysics

Measurements of the Sunyaev-Zel'dovich (hereafter SZ) effect distortion of the cosmic microwave background provide us with an independent method to derive the gas temperature of galaxy clusters. In merging galaxy clusters the gas distribution is inhomogeneous and, therefore, the method of temperature measuring based on the SZ effect should be more relevant than that based on an X-ray emission analysis. Here we study a method for measuring the gas temperature in merging clusters by means of the SZ effect. Our calculations of intensity maps of the SZ effect include relativistic corrections considered within the framework of the Wright formalism and utilize a cosmological numerical simulation of a merging galaxy cluster evolved with its baryon physics. We found that the gas temperature in merging clusters can be measured by means of the ratio of the SZ intensity at a low frequency (128 GHz) to that at a high frequency (369 GHz). This SZ intensity ratio permits us to reveal prominent features of the temperature structure caused by violent merger shock waves. Therefore, measurements of the ratio of the SZ intensities are a promising tool for measuring gas temperature in merging galaxy clusters., Comment: 6 pages, 6 figures, accepted for publication in Astronomy and Astrophysics

X-ray imaging observatories have revealed hydrodynamic structures with linear scales ~ 10 kpc in clusters of galaxies, such as shock waves in the 1E0657-56 and A520 galaxy clusters and the hot plasma bubble in the MKW 3s cluster. The future X-ray observatory IXO will resolve for the first time the metal distribution in galaxy clusters at the these scales. Heating of plasmas by shocks and AGN activities can result in non-equilibrium ionization states of metal ions. We study the effect of the non-equilibrium ionization at linear scales, 6 pages, 6 figures, accepted for publication in Astronomy and Astrophysics

We study the energetics of galaxy cluster atmospheres by analyzing the SZ effect spectra around the crossover frequency. We calculated analytically the expressions of both the crossover frequency and the spectral slope of the SZE around the crossover frequency in various cases: a thermal electron population; a power-law, non-thermal electron population; and a population of electrons experiencing a stochastic acceleration. We find that the value of the crossover frequency X_0 of the SZE depends significantly on the cluster peculiar velocity V_r (which determines the amplitude of the kinematic SZE), while the value of the slope of the SZE does not depend on the kinematic SZE spectrum in the optimal frequency range around the crossover frequency of the thermal SZE, i.e. in the (a-dimensional) frequency range x = 3.5 - 4.5. Thus, while the amplitude of the kinematic SZE produces a systematic bias in the position of the crossover frequency, it does not affect significantly the spectral slope of the SZE. We therefore propose to use measurements of the spectral slope of the SZE to obtain unbiased information about the specific properties of various electron distributions in galaxy clusters as well as in other cosmic structures in which a SZE can be produced., 11 pages, 8 figures, published in A&A

The interpretation of hard X-ray emission from galaxy clusters is still ambiguous and different models proposed can be probed using various observational methods. Here we explore a new method based on Fe line observations. Spectral line emissivities have usually been calculated for a Maxwellian electron distribution. In this paper a generalized approach to calculate the iron line flux for a modified Maxwellian distribution is considered. We have calculated the flux ratio of iron lines for the various possible populations of electrons that have been proposed to account for measurements of hard X-ray excess emission from the clusters A2199 and Coma. We found that the influence of the suprathermal electron population on the flux ratio is more prominent in low temperature clusters (as Abell 2199) than in high temperature clusters (as Coma)., 6 pages, 3 figures, accepted for publication in A&A

The existence of dark matter can be proved in an astrophysical context by the discovery of a system in which the observed baryons and the inferred dark matter are spatially segregated, such as the bullet cluster (1E0657-558). The full descriptions of the dark matter halo and X-ray gas substructure motions are necessary to forecast the location of the dark halo from X-ray maps, which can be confirmed by the detection of a galaxy concentration or by gravitational lensing. We present an analytical hydrodynamic model to determine the distance between the X-ray and dark-matter components and the Mach number of the merger shock. An approximate solution is given for the problem of the substructure propagation in merging clusters. A new method to predict the position of a dark matter halo in clusters, where there is a separation between the X-ray gas and the dark halo, is proposed and applied to the clusters 1E0657-558 and Abell 1763., Accepted for publication in Astronomy & Astrophysics

Emission of AGNs and neutral pion decay - are the two most natural mechanisms, that could make a galaxy cluster be a source of gamma-rays in the GeV regime. We revisited this problem by using 52.5-month FERMI-LAT data above 10 GeV and stacking 55 clusters from the HIFLUGS sample of the X-ray brightest clusters. The choice of >10 GeV photons is optimal from the point of view of angular resolution, while the sample selection optimizes the chances of detecting signatures of the neutral pion decay, arising from hadronic interactions of relativistic protons with an intra-cluster medium, which scale with the X-ray flux. In the stacked data we detected a signal for the central 0.25 deg circle at the level of 4.3 sigma. An evidence for a spatial extent of the signal is marginal. A subsample of cool-core clusters has higher count rate 1.9+/-0.3 per cluster compared to the subsample of non-cool core clusters 1.3+/-0.2. Several independent arguments suggest that the contribution of AGNs to the observed signal is substantial if not dominant. No strong support for the large contribution of pion decay was found. In terms of a limit on the relativistic protons energy density, we got an upper limit of ~1.5% relative to the gas thermal energy density, provided that the spectrum of relativistic protons is hard (s=4.1 in dN/dp=p^-s). This estimate assumes that relativistic and thermal components are mixed. For softer spectra the limits are weaker., 13 pages, 6 figures, submitted to A&A on August, 6

X-ray cavities and extended radio sources (`cocoons') surrounding active galactic nuclei (AGN) have been detected by the Chandra X-ray mission and radio interferometers. A joint analysis of X-ray and radio maps suggests that pressure values of non-thermal radio-emitting particles derived from the radio maps are not sufficient to inflate the X-ray cavities. We propose using the Sunyaev-Zel'dovich (SZ) effect, whose intensity strongly depends on the pressure, to find the hitherto undetected, dynamically-dominant component in the radio cocoons. We demonstrate that the spectral function at a frequency of 217 GHz has an absolute maximum at a temperature higher than $10^9$ K, therefore the measurement of the SZ effect at this frequency is a powerful tool for potentially revealing the dynamically-dominant component inside AGN jet-driven radio cocoons. A new method is proposed for excluding the contribution from the low energy, non-relativistic electrons to the SZ effect by means of observations at two frequencies. We show how one may correct for a possible contribution from the kinematic SZ effect. The intensity maps of the SZ effect are calculated for the self-similar Sedov solution, and application of a predicted ring-like structure on the SZ map at a frequency of 217 GHz is proposed to determine the energy released during the active jet stage. The SZ intensity map for an AGN cocoon in a distant elliptical is calculated using a 2-D numerical simulation and including relativistic corrections to the SZ effect. We show the intensity spectrum of the SZ effect is flat at high frequencies if gas temperature is as high as $k_\mathrm{b} T_{\mathrm{e}}=500$ keV., 12 pages, 15 figures, accepted for publication in Astronomy and Astrophysics