Denis Yurin

This paper presents the architecture of the Kazakhstani National Virtual Observatory (KazVO)—an International Virtual Observatory Alliance (IVOA) compliant node that unifies the heterogeneous observational datasets of the Fesenkov Astrophysical Institute (FAI). The architectural foundation of the system is built upon a partitioned Data Lake, a German Astrophysical Virtual Observatory (GAVO) Data Center Helper Suite (DaCHS) publishing backend, and a PostgreSQL database in which metadata for published observational products are mapped to IVOA ObsCore, while catalogs and simulation grids use dedicated relational tables. We follow Open Science principles by introducing a metadata-only showcase model based on a four-class data embargo mechanism. Machine-to-Machine services deployed via IVOA protocols are exposed through the KazVO publishing registry registered in the global Registry of Registries (RofR), enabling analysis of Kazakhstani observational assets within external clients such as Tool for OPerations on Catalogues And Tables (TOPCAT), Aladin, and PyVO. The current implementation combines operational VO publication services and targeted photometric processing with scheduled, batch-mode data ingestion, supporting access to published historical and modern observational holdings. Replication has been validated on pilot datasets, while routine deployment at the observing sites and automated reduction of modern spectroscopic streams remain under development. The architecture provides a framework for progressively integrating these components into a complete data lifecycle.

This paper presents an automated pipeline for wavelength calibration of slit-based astronomical spectra, combining robust peak-matching techniques with a lightweight preprocessing step. The method is based on initial peak alignment using Dynamic Time Warping (DTW), followed by refinement of the dispersion solution with the Random Sample Consensus (RANSAC) algorithm. To ensure consistency between observed and reference spectra, a compact one-dimensional convolutional neural network (CNN) is employed at the preprocessing stage to identify the spectral range and corresponding diffraction grating. This step enables the selection of an appropriate reference spectrum but does not directly affect the calibration procedure. The DTW-based approach provides reliable initial correspondences between spectral peaks under nonlinear distortions and noise, while RANSAC filtering removes incorrect matches and yields a robust polynomial dispersion solution. The method is validated on real observational data from calibration lamps and demonstrates stable performance, high matching accuracy, and full automation capability. Compared to traditional manual or semi-automatic approaches, the proposed pipeline significantly reduces processing time while maintaining calibration precision. The developed solution is planned to be deployed as a service in the virtual observatory infrastructure and is applicable for processing numerous spectral data.

We establish the multimessenger mechanics of episodic mass transfer in supermassive black hole binaries stalled within circumbinary discs. Utilizing continuous wavelet transforms, we isolate localized gas clumps at the cavity edge and track their evolution. By regularizing the forced fluid equations at Lindblad resonances via the inhomogeneous Airy differential equation, we bypass linear Wentzel–Kramers–Brillouin singularities to extract the finite wave amplitudes that trigger nonlinear shock formation. These shocks produce bounded accretion bursts. We model the time-domain thermal luminosity, utilizing the Fourier shift theorem to derive an analytical power spectral density that forms an extended harmonic cascade. The superposition of the accretion streams generates a spectral beat frequency, providing a theoretical diagnostic template to estimate the binary mass ratio, though sensitive to intrinsic cavity shape. The radiative cooling of shock-accelerated electrons produces a multiwavelength spectral energy distribution from a synchrotron radio continuum to an inverse-Compton gamma-ray tail, regulated by pair-production thermostats. We identify a relativistic signature: a discontinuous, high-frequency gravitational wave sideband termed the “background gas humming.” We analytically differentiate this from steady spiral pattern speeds, showing it arises from the physical advection of highly localized, transient fluid hot spots following accretion shocks. Evaluating the asymptotic properties of the Airy regularization, we show that this humming manifests as a sequence of discrete high-frequency bursts with temporal quiescence gaps that systematically compress as the cavity shrinks. We show that the instantaneous accretion rate of the gas actively trapped within the cavity violently amplifies prior to decoupling, culminating in a terminal burst near 4 mHz (normalized to a 10 ⁶ M _⊙ system) that serves as a multimessenger precursor to the final vacuum inspiral.

We investigate the orbital eccentricity evolution of supermassive black hole binaries (SMBHBs; 10 ⁴ –10 ⁷ M _⊙ ) within galactic environments. Merger timescales depend on eccentricity when gravitational-wave (GW) emission dominates. We analyze the dynamics in triaxial merger remnants and subsequent interactions with geometrically thick nuclear disks. Gravitational torques in triaxial potentials extract angular momentum ( T _J ≪ T _E ), resulting in binary formation with high initial eccentricities ( e > 0.95). We analyze the binary–disk interaction using a 3D analytical framework incorporating the Airy formalism and present a self-consistent derivation demonstrating that the 3D suppression of high-order torques leads to distinct scalings with disk thickness ( h ), with migration rates τ a − 1 ∝ h − 3 and eccentricity damping rates τ e − 1 ∝ h − 5 , which establish a timescale hierarchy, τ _e / τ _a ∝ h ² . For typical parameters, eccentricity damping is significantly faster than orbital decay ( τ _e ≈ 0.04 τ _a ). We further develop a wavelet-based formalism to quantify the impact of disk inhomogeneities arising from accretion feedback and turbulence. We derive the stochastic torque variance in the wavelet domain and employ a Fokker–Planck analysis to determine the equilibrium eccentricity distribution. While stochastic fluctuations counteract deterministic damping, the strong damping imposed by the thick disk geometry ensures the equilibrium eccentricity remains small unless the fluctuations are highly nonlinear. Hence, highly eccentric born SMBHBs are rapidly circularized. This “circularization trap” forces binaries to approach the GW-dominated regime on nearly circular orbits, prolonging the total merger timescale. This introduces a cosmological delay (0.3–2.5 Gyr) governed by stellar relaxation.

We present a modification of the original GalIC code, which is designed to generate equilibrium initial conditions for numerical $N$-body models of collisionless, gravitationally bound systems. The proposed approach focuses on improving the procedure for assigning initial particle velocities, which is crucial for ensuring the stability and physical consistency of equilibrium models. Instead of drawing trial velocities from a uniform distribution bounded by the local escape velocity, we introduce a Gaussian-like distribution with compact support. Its dispersion is adapted to the local properties of the system and is derived from the Jeans equations. This choice provides a more physically motivated sampling of velocity space while preserving the bound nature of the system. A detailed comparison with the original GalIC method is performed using isotropic Hernquist models. We demonstrate that the modified algorithm converges significantly faster and produces well-resolved time-averaged mass profiles and velocity distributions. The resulting models show improved convergence toward the target distribution function while maintaining a comparable computational cost per iteration. Overall, the proposed modification provides a more efficient and physically realistic framework for generating equilibrium $N$-body initial conditions in collisionless stellar dynamical systems.

We present the conceptual framework of the Astronomical Hub (AstroHub), a unified platform combining various optical instruments at a single observatory. Its major approach lies in arranging conditions for research groups to install telescopes and equipment and participate in joint projects. AstroHub is planned to integrate Virtual Observatory (VO) tools, FAIR data principles, and a telescope network to create a powerful and attractive ecosystem for both robust near-Earth object (NEO) monitoring and diverse deep space research. We provide an overview of the AstroHub development directions in the case study of the Assy-Turgen Observatory.

We present a simple method for estimating fundamental frequencies from orbit’s time series of triaxial dynamical systems based on the zero-crossing technique. The simplicity and high performance of the method make it a viable alternative to more advanced, but rather complex and computationally expensive techniques based on Fourier spectral analysis and iterative torus-mapping with action-angle variables. More importantly, the method provides a simple and quick way to identify irregular orbits and quantify their level of chaoticity, allowing to detect even a subtle onset of chaos. To validate the proposed algorithm, we performed comparison tests with synthetic quasi-periodic signals and with other methods using the triaxial Dehnen potential. We found noticeable differences in frequency maps constructed with our method and methods based on Fourier spectral analysis that we attributed to the way we assign static properties to chaotic orbits. At the same time, our frequency maps turn out to be in very good agreement with the maps obtained using the action-based technique.

Peculiarities gut microbiome have been studied in poultry with using sorbent and enzymatic preparation in feed composition individually or together. The experimants have been carried out in broilers in “Mikhailovski” SUEP (North Ossetia — Alania). It has been established as the results of the experiment that complex usage sorbent and enzymatic preparation in feed composition has activated fermentation processes in poultry gut and influenced positively on different gut sectors microflora.

Aims. We carry out the self-consistent dynamic evolution of the orbital structure of Milky Way globular clusters. This allows us to estimate possible and probable close passages and even collisions of the clusters with each other. Methods. We reproduced the orbits of 147 globular clusters in 10 Gyr lookback time using our own high-order N-body parallel dynamic φ-GPU code. The initial conditions (three coordinates and three velocities for the present time) were derived from the Gaia DR3 catalogue. For each of the GCs, 1000 initial conditions were additionally generated, taking the Gaia measurement errors into account. The galaxy is represented by five external potentials from the IllustrisTNG-100, whose masses and sizes of the disk and halo components are similar to the physical values of the Milky Way at present. Results. We present a statistical analysis of the cumulative close passages rate: About ten close passages with relative distances shorter than 50 pc for every billion years for each of the five external potentials. We present the 22 most reliable collision pairs with a good probability. As an example: Terzan 4 vs. Terzan 2 (49%), Terzan 4 vs. NGC 6624 (44%), Terzan 4 vs. Terzan 5 (40%), Terzan 4 vs. NGC 6440 (40%), and Terzan 4 vs. Liller 1 (42%). The most active globular cluster in the collision sense is Terzan 4, which has 5.65 collision events on average (averaged over all individual 1000 initial condition realisations). Most collisions are located inside the Galactic disk and form two ring-like structures. The first ring-like structure has the highest collision number density at ∼1 kpc, and the second sturcture has a maximum at ∼2 kpc. Conclusions. Based on our numerical simulations, we can conclude that the few dozen Milky Way globular clusters probably undergo some close encounters and even possible collisions during their lifetimes, which can significantly affect their individual dynamical evolution and possibly even their stellar content.