Sergey Khoperskov

Sergey Khoperskov
Observatoire de Paris · Laboratoire Galaxies, Etoiles, Physique et Instrumentation (GEPI)

PhD

About

34
Publications
2,397
Reads
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295
Citations
Additional affiliations
May 2014 - December 2015
University of Milan
Position
  • PostDoc Position
February 2013 - present
Lomonosov Moscow State University
Position
  • Extragalactic astronomy
September 2011 - present
Russian Academy of Sciences
Position
  • Evolution of disk galaxies: study of structural hierarchy
Education
September 2011 - April 2013
Institute of Astronomy of the Russian Academy of Sciences
Field of study
  • astrophysics
September 2009 - June 2011
Volgograd State University
Field of study
  • Computational physics
September 2005 - June 2009
Volgograd State University
Field of study
  • Physics

Publications

Publications (34)
Article
The formation scenario for giant low surface brightness (gLSB) galaxies with discs as large as 100 kpc still remains unclear. These stellar systems are rare and very hard to observe, therefore a detailed insight on every additional object helps to understand their nature. Here we present a detailed observational study of the gLSB UGC 1922 performed...
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Full-text available
A parallel implementation of the magneto-hydrodynamical code for global modeling of the galactic evolution is reported. The code is parallelized by using MPI interface, and it shows ideal scaling up to 200-300 cores on Lomonosov supercomputer with fast interconnect. In the benchmarking of this code, we study the dynamics of a magnetized gaseous dis...
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This paper focuses on the parallel implementation of a direct $N$-body method~(particle-particle algorithm) and the application of multiple GPUs for galactic dynamics simulations. Application of a hybrid OpenMP-CUDA technology is considered for models with a number of particles $N \sim 10^5 \div 10^7$. By means of $N$-body simulations of gravitatio...
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We performed long-slit spectral observations of two SB-type galaxies: NGC 5347, UGC 1344. They were previously suspected as the galaxies with unusually low mass-to-light ratios (on the ground of mass estimates from the Hi linewidths), which are in conflict with their observed colours. The observations were conducted at the Russian 6-m telescope. Th...
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Dark matter in galaxies, its abundance, and its distribution remain a subject of long-standing discussion, especially in view of the fact that neither dark matter particles nor dark matter bodies have yet been found. Experts' opinions range from a very large number of completely dark galaxies exist to nonbaryonic dark matter does not exist at all i...
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We use observational gaseous and stellar density distributions in the disk of the Milky Way (MW) galaxy together with the disk rotation curve and measured disk velocity dispersion to build collisionless and combined collisionless-gaseous equilibrium models of the Milky Way disk. A purely collisionless MW disk is unstable towards the development of...
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We use N-body/hydrodynamic simulations of a Milky Way-like galaxy to study the physical properties of giant molecular clouds and star formation rate on different spatial scales. We confirm the previous estimates that the dark gas fraction in molecular clouds reaches about 30% by mass. We find that conversion factors for individual molecular clouds...
Article
By means of 3D hydrodynamical simulations, in a separate paper we have discussed the properties of non-axisymmetric density wave trains in the outermost regions of galaxy disks, based on the picture that self-excited global spiral modes in the bright optical stellar disk are accompanied by low-amplitude short trailing wave signals outside corotatio...
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We investigate the physical properties of molecular clouds in disc galaxies with different morphologies: a galaxy without prominent structure, a spiral barred galaxy and a galaxy with flocculent structure. Our N-body/hydrodynamical simulations take into account non-equilibrium H2 and CO chemical kinetics, self-gravity, star formation and feedback p...
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We investigate physical properties of molecular clouds in the disc galaxies with different morphologies: a galaxy without prominent structure, a spiral barred galaxy and a galaxy with flocculent structure. Our $N$-body/hydrodynamical simulations take into account non-equilibrium H$_2$ and CO chemical kinetics, self-gravity, star formation and feedb...
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Most of giant molecular clouds (GMCs) in M 33 are connected with spiral-like gaseous arms (filaments) with the exception of the inner 2 kpc region where the link between the arms and GMCs disappears (see Tosaki et al. 2011). We check whether it may be caused by the dynamic friction retarding the clouds. Using semi-analytical model for this galaxy w...
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We suggest a possible mechanism for the formation of non-tidal gaseous structures in galactic outskirts. According to recent observations, extended spiral structures are detected beyond the optical radii Ropt in numerous disk galaxies. Such features can be clearly seen in deep HI and UV images (e.g., NGC 3198, NGC 3359, NGC 2841, NGC 3198). We argu...
Article
Deep H i observations of the outer parts of disc galaxies demonstrate the frequent presence of extended, well-developed spiral arms far beyond the optical radius. To understand the nature and the origin of such outer spiral structure, we investigate the propagation in the outer gaseous disc of large-scale spiral waves excited in the bright optical...
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Full-text available
Journal of Physics: Conference Series. 2014. V. 510. Issue 1. 012011. 13 p. We present a numerical code for multi-component simulation of the galactic evolution. Our code includes the following parts: N-body is used to evolve dark matter, stellar dynamics and dust grains, gas dynamics is based on TVD-MUSCL scheme with the extra modules for thermal...
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The polar ring galaxies (PRGs) represent an interesting type of peculiar systems in which the outer matter is rotating in the plane which is roughly perpendicular to the disk of the main galaxy. Despite the long-lasting study of the PRGs, the amount of observational data detailed enough is insufficient; there still remain many open questions. Among...
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Full-text available
The polar ring galaxies (PRGs) represent an interesting type of peculiar systems in which the outer matter is rotating in the plane which is roughly perpendicular to the disk of the main galaxy. Despite the long lasting study of the PRGs there is a lack of the detailed enough observational data, there are still many open questions. Among the most i...
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Full-text available
We present a numerical code for multi-component simulation of the galactic evolution. Our code includes the following parts: N-body is used to evolve dark matter, stellar dynamics and dust grains, gas dynamics is based on TVD-MUSCL scheme with the extra modules for thermal processes, star formation, magnetic fields, chemical kinetics and multi-spec...
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Full-text available
With the aim to determine the spatial distribution of dark matter, we investigate the polar ring galaxy NGC 4262. We used the stellar kinematics data for the central galaxy obtained from optical spectroscopy together with information about the kinematics of the neutral hydrogen for polar component. It was shown that NGC 4262 is the classic polar ri...
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With the aim of determining the spatial distribution of the dark matter halo, we investigate two polar ring galaxies, NGC 4262 and SPRC-7. For both galaxies, the stellar kinematics data for the central galaxy were obtained from optical spectroscopy at the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences. Inf...
Article
We develop a 3D dynamical model of dust outflows from galactic discs. The outflows are initiated by multiple SN explosions in a magnetized interstellar medium (ISM) with a gravitationally stratified density distribution. Dust grains are treated as particles in cells interacting collisionally with gas, and forced by stellar radiation of the disc and...
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Some of the ventilation problems in the large industrial premises based on direct numerical integration of unsteady three-dimensional hydrodynamics equations with the real geometrical parameters are investigated. The model takes into account the work of the different ventilation and aspiration devices and the availability of metallurgical furnaces...
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Using N-body simulations (N ∼ 106–107), we examine how a non-axisymmetric dark halo affects the dynamical evolution of the structure in collisionless (stellar) discs. We demonstrate how the model parameters such as mass of the halo, initial conditions in the disc and the halo axis ratio affect morphology and kinematics of the stellar discs. We show...
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Using N-body simulations (N∼10^6−10^7), we examine how a non-axisymmetric dark halo affects the dynamical evolution of the structure in collisionless (stellar) discs. We demonstrate how the model parameters such as mass of the halo, initial conditions in the disc and the halo axes ratio affect morphology and kinematics of the stellar discs. We show...
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Spectroscopic observations at the Russian 6-m telescope are used to study the two polar ring galaxies (PRGs) from the catalogue by Moiseev et al.: SPRC-7 and SPRC-260. We have analyzed the kinematics of the stellar component of the central galaxies as well as the ionized gas kinematics in the external ring structures. The disc-halo decomposition of...
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Using observational data, we build numerical N-body, hydrodynamical and combined equilibrium models for the spiral galaxy NGC 5247. The models turn out to be unstable as regards spiral structure formation. We simulate scenarios of spiral structure formation for different sets of equilibrium rotation curves, radial velocity-dispersion profiles and d...
Article
Khoperskov S.A., Khoperskov A.V., Khrykin I.S., Korchagin V.I., Casetti-Dinescu D.I., Girard T., van Altena W., Maitra D. Global Gravitationally-Organized Spiral Waves and the Structure of NGC 5247 // Monthly Notices of the Royal Astronomical Society, 2012, V.427. No 3. p.1983-1993. Using observational data, we build numerical N-body, hydrodynamica...
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Full-text available
Spectroscopic observations at the Russian 6-m telescope are used to study the two polar ring galaxies (PRGs) from the catalogue by Moiseev et al.: SPRC-7 and SPRC-260. We have analyzed the kinematics of the stellar component of the central galaxies as well as the ionized gas kinematics in the external ring structures. The disc-halo decomposition of...
Article
Full-text available
Using 3D hydrodynamic calculations we simulate formation of molecular clouds in the Galaxy. The simulations take into account molecular hydrogen chemical kinetics, cooling and heating processes. Comprehensive gravitational potential accounts for contributions from the stellar bulge, two- and four-armed spiral structure, stellar disc, dark halo and...
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In this paper we examine the effect of the formation and evolution of the disk galaxy on the distribution of dark halo matter. We have made simulations of isolated dark matter (DM) halo and two component (DM + baryons). N-body technique was used for stellar and DM particles and TVD MUSCL scheme for gas-dynamic simulations. The simulations include t...
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This work is devoted to the numerical multidimensional computational modeling of a gaseous disk in an external potential of the spiral stellar density wave. The possibility of polygonal structure formation in spiral galaxies (see [1, 4, 5]) was studied. Our simulations demonstrated that polygonal structures result from spiral shock instabilities. P...
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The dynamics of a galactic disk in a non-axisymmetric (triaxial) dark halo is studied in detail using high-resolution, numerical, hydrodynamical models. A long-lived, two-armed spiral pattern is generated for a wide range of parameters. The spiral structure is global, and the number of turns can be two or three, depending on the model parameters. T...
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The results of numerical simulations of the dynamics of galactic disks, which are submerged into nonaxisymmetric dark massive halo are discussed. Galaxy disks dynamics in the nonaxisymmetric (triaxial) dark halo were investigated in detail by the high resolution numerical hydrodynamical methods (TVD \& SPH) and N-body models. The long-lived two arm...
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Full-text available
The results of numerical simulations of a gaseous disk in the potential of a stellar spiral density wave are presented. The conditions under which straightened spiral arm segments (rows) form in the gas component are studied. These features of the spiral structure were identified in a series of works by A.D. Chernin with coauthors. Gas-dynamic simu...

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