Vladislav Izmodenov

• Ph.D., Dr. Sci.
• Lomonosov Moscow State University at Lomonosov Moscow State University

One of the most remarkable discoveries by the IBEX is the ribbon - a narrow band of enhanced ENA fluxes observed in the sky. The prevailing explanation attributes the IBEX ribbon to the secondary ENA mechanism. In this process, primary H ENAs, produced via charge exchange between solar wind (SW) protons and interstellar H atoms within the heliosphe...

Interstellar hydrogen atoms (H atoms) penetrate into the heliosphere through the region of the solar wind interaction with the interstellar plasma due to their large mean free path. Resonant charge exchange of H atoms with protons has been considered as the main interaction process between the components. In the majority of models, other processes...

Interstellar hydrogen atoms (H atoms) penetrate into the heliosphere through the region of the solar wind interaction with the interstellar plasma due to their large mean free path. Resonant charge exchange of H atoms with protons has been considered as the main interaction process between the components. In the majority of models, other processes...

Рассматриваются задачи и проблемы, связанные с развитием космических исследований на кафедре аэромеханики и газовой динамики механико-математического факультета МГУ им. М.В. Ломоносова. Дается обзор становления космической тематики на кафедре, отмечаются основные направления и методы исследований. Подробно представлены результаты по созданию теорет...

A subsonic flow of an ideal gas through a flat channel in the presence of a mass force field is considered. The forces acting on the gas are reduced to the attraction to the channel axis in a certain region of the channel. It has been shown that the occurrence of a zone of increased pressure along the axis of a channel leads to the formation of a p...

The interaction between stellar winds and the partially ionized local interstellar medium (LISM) is quite common in astrophysics. However, the main difficulty in describing the neutral components lies in the fact that the mean free path of an interstellar atom, l, can be comparable to the characteristic size of an astrosphere, L (i.e., the Knudsen...

Interstellar dust enters the heliosphere due to the relative motion of the Sun and the Local Interstellar Cloud, which contains the Sun. The dynamics of interstellar dust particles is governed mainly by the electromagnetic force. The direction of this force depends on the polarity of the heliospheric magnetic field. In turn, polarity is a function...

Aims. Interstellar dust (ISD) particles penetrate the heliosphere because of the relative motion of the local interstellar cloud and the Sun. The penetrated particles pass through the heliospheric interface, that is, the region in which solar wind and interstellar plasma interact. As a result, the ISD flow is modified after the passage through this...

The interaction between stellar winds and the partially ionized local interstellar medium (LISM) is quite common in astrophysics. However, the main difficulty in describing the neutral components lies in the fact that the mean free path of an interstellar atom, l, can be comparable to the characteristic size of an astrosphere, L (i.e., the Knudsen...

Determining the magnitude and direction of the interstellar magnetic field ( B ISM ) is a long-standing problem. To date, some methods to infer the direction and magnitude have utilized best-fit models to the positions of the termination shock and heliopause measured by Voyager 1 and 2. Other models use the circularity of the Interstellar Boundary...

This paper examines the geometry of interstellar magnetic field lines close to the boundary of the heliosphere in the direction of the unperturbed local interstellar magnetic field, where the field lines are spread apart by the heliopause (HP). Such field parting establishes a region of weaker magnetic field of about 300 au in size in the northern...

Ly α absorption profiles have been used to detect astrospheres and heliospheric absorption from the hydrogen wall and heliotail. Using magnetohydrodynamic models of the heliosphere, we can compare simulated to observed Ly α profiles to probe the neutral hydrogen within and near the heliosphere. There is an ongoing controversy whether the heliospher...

Shock boundary layers are regions bounded by a shock wave on the one side and tangential discontinuity on the other side. These boundary layers are commonly observed in astrophysics. For example, they exist in the regions of the interaction of the stellar winds with the surrounding interstellar medium. Additionally, the shock layers are often penet...

Observations of the Lyman-a emissions from Interplanetary Hydrogen (IPH) atoms are made from Mars’ orbit using a high spectral resolution instrument in echelle configuration. The measurements can uniquely be used to resolve IPH from planetary H emissions and to subsequently determine the brightness, velocity, and thermal broadening of the IPH flow...

Measuring energetic neutral atoms (ENAs) allows for the remote observation of ion populations from the frontiers of our heliosphere. In this study, we compare the ENAs observed with the IBEX-Lo instrument onboard the Interstellar Boundary Explorer with ENA predictions from two heliosphere models. In contrast to previous studies, this paper presents...

The hydrogen atoms penetrate the heliosphere from the local interstellar medium, and while being ionized, they form the population of pickup protons. The distribution of pickup protons is modified by the adiabatic heating (cooling) induced by the solar wind plasma compression (expansion). In this study, we emphasize the importance of the adiabatic...

The hydrogen atoms penetrate the heliosphere from the local interstellar medium, and while being ionized, they form the population of pickup protons. The distribution of pickup protons is modified by the adiabatic heating (cooling) induced by the solar wind plasma compression (expansion). In this study, we emphasize the importance of the adiabatic...

Observations of the Lyman‐α emissions from Interplanetary Hydrogen (IPH) atoms are made from Mars' orbit using a high spectral resolution instrument in echelle configuration. The measurements can uniquely be used to resolve IPH from planetary H emissions and to subsequently determine the brightness, velocity, and thermal broadening of the IPH flow...

Interstellar dust grains penetrate into the heliosphere (region in which the solar wind propagates) due to the relative motion of the Sun and the Local Interstellar Medium (LISM). Inside the heliosphere, the motion of dust particles is mainly governed by the electromagnetic force determined by the heliospheric magnetic field. Under the action of th...

Voyager 1 and 2 crossed the heliopause at ∼122 AU in 2012 and ∼119 AU in 2018, respectively. It was quite a surprise because the thickness of the inner heliosheath obtained by the existing at that time models of the global heliosphere was significantly larger (by 20-40 AU). Until now, the problem of the heliosheath thickness has not been fully reso...

Voyager 1 and 2 crossed the heliopause at $\sim$122 AU in 2012 and $\sim$119 AU in 2018, respectively. It was quite a surprise because the thickness of the inner heliosheath obtained by the existing at that time models of the global heliosphere was significantly larger (by 20-40 AU). Until now, the problem of the heliosheath thickness has not been...

The shape of the heliosphere is currently under active debate. Energetic neutral atoms (ENAs) offer the best method for investigating the global structure of the heliosphere. To date, the Interstellar Boundary Explorer (IBEX) and the Ion and Neutral Camera (INCA) that was on board Cassini provide the only global ENA observations of the heliosphere....

Interstellar dust grains penetrate into the heliosphere (region in which the solar wind propagates) due to the relative motion of the Sun and the Local Interstellar Medium (LISM). Inside the heliosphere, the motion of dust particles is mainly governed by the electromagnetic force determined by the heliospheric magnetic field. Under the action of th...

The problem of the interaction of a hypersonic stellar wind with the surrounding interstellar medium is considered. The media are regarded as fully ionized and are accounted for within the framework of ideal magnetohydrodynamics. The scientific novelty consists in taking into account the magnetic field of a star. The magnetic field qualitatively ch...

The main goal of the paper is to explore why observations of many astrospheres (or circumstellar bubbles) show quite stable and smooth structures of astropauses - the tangential discontinuities separating the stellar and interstellar winds, - while both theory and numerical simulations suggest that tangential discontinuities are unstable due to wel...

Interstellar dust particles were discovered in situ, in the solar system, with the Ulysses mission’s dust detector in 1992. Ever since, more interstellar dust particles have been measured inside the solar system by various missions, providing insight into not only the composition of such far-away visitors, but also in their dynamics and interaction...

The main goal of this paper is to explore why observations of many astrospheres (or circumstellar bubbles) show quite stable and smooth structures of astropauses – the tangential discontinuities separating the stellar and interstellar winds – while both theory and numerical simulations suggest that tangential discontinuities are unstable due to wel...

Aims. One of the important discoveries made by Voyager-2 is the nonadiabatic radial profile of the solar wind proton temperature. This phenomenon has been studied for several decades. The dissipation of turbulence energy has been proposed as the main physical process responsible for the temperature profile. The turbulence is both convected with the...

One of the important discoveries made by Voyager-2 is the nonadiabatic radial profile of the solar wind proton temperature. This phenomenon has been studied for several decades. The dissipation of turbulence energy has been proposed as the main physical process responsible for the temperature profile. The turbulence is both convected with the solar...

11 Understanding the role of neutral atoms in the heliospheric interface (between the bow shock 12 and heliopause) is critical to identifying dynamics within our local bubble. This article recommends 13 building upon existing measurements with new, high-spectral resolution observations of H Lyman-a, 14 from a heliospheric mapping mission, to resolv...

This review summarizes our current understanding of the outer heliosphere and local interstellar medium (LISM) inferred from observations and modeling of interplanetary Lyman- $\alpha $ α emission. The emission is produced by solar Lyman- $\alpha $ α photons (121.567 nm) backscattered by interstellar H atoms inflowing to the heliosphere from the LI...

This review summarizes our current understanding of the outer heliosphere and local interstellar medium (LISM) inferred from observations and modeling of interplanetary Lyman-$\alpha$ emission. The emission is produced by solar Lyman-alpha photons (121.567 nm) backscattered by interstellar H atoms inflowing to the heliosphere from the LISM. Studies...

Thanks to dedicated long-term missions like Voyager and GOES over the past 50 years, much insight has been gained on the activity of our Sun, the solar wind, its interaction with the interstellar medium, and, thus, about the formation, the evolution, and the structure of the heliosphere. Additionally, with the help of multi-wavelength observations...

Our understanding of the interaction of the large-scale heliosphere with the local interstellar medium (LISM) has undergone a profound change since the very earliest analyses of the problem. In part, the revisions have been a consequence of ever-improving and widening observational results, especially those that identified the entrance of interstel...

This review summarizes the current state of research aiming at a description of the global heliosphere using both analytical and numerical modeling efforts, particularly in view of the overall plasma/neutral flow and magnetic field structure, and its relation to energetic neutral atoms. Being part of a larger volume on current heliospheric research...

As the heliosphere moves through the surrounding interstellar medium, a fraction of the interstellar neutral helium, hydrogen, and heavier species crossing the heliopause make it to the inner heliosphere as neutral atoms with energies ranging from few eV to several hundred eV. In addition, energetic neutral hydrogen atoms originating from solar win...

Interstellar neutrals (ISNs), pick-up ions (PUIs), and energetic neutral atoms (ENAs) are fundamental constituents of the heliosphere and its interaction with the neighboring interstellar medium. Here, we focus on selected aspects of present-day theory and modeling of these particles. In the last decades, progress in the understanding of the role o...

Pickup protons originate as a result of the ionization of hydrogen atoms in the supersonic solar wind, forming the suprathermal component of protons in the heliosphere. While they are being picked by the heliospheric magnetic field and convected into the heliosheath, the pickup protons may suffer stochastic acceleration from the solar wind turbulen...

The heliosphere is the bubble formed by the solar wind as it interacts with the interstellar medium (ISM). The collimation of the heliosheath (HS) flows by the solar magnetic field in the heliotail into distinct north and south columns (jets) is seen in recent global simulations of the heliosphere. However, there is disagreement between the models...

Global models of the heliosphere are critical tools used in the interpretation of heliospheric observations. There are several three-dimensional magnetohydrodynamic (MHD) heliospheric models that rely on different strategies and assumptions. Until now only one paper has compared global heliosphere models, but without magnetic field effects. We comp...

Energetic neutral atom (ENA) models typically require post-processing routines to convert the distributions of plasma and H atoms into ENA maps. Here we investigate how two kinetic-MHD models of the heliosphere (the BU and Moscow models) manifest in modeled ENA maps using the same prescription and how they compare with Interstellar Boundary Explore...

The pickup protons originate as a result of the ionization of hydrogen atoms in the supersonic solar wind, forming the suprathermal component of protons in the heliosphere. While picked by the heliospheric magnetic field and convected into the heliosheath, the pickup protons may suffer the stochastic acceleration by the solar wind turbulence in the...

Energetic neutral atom (ENA) models typically require post-processing routines to convert the distributions of plasma and H atoms into ENA maps. Here we investigate how two different kinetic-MHD models of the heliosphere (the BU and Moscow models) manifest in modeled ENA maps using the same prescription and how they compare with Interstellar Bounda...

Global models of the heliosphere are critical tools used in the interpretation of heliospheric observations. There are several three-dimensional magnetohydrodynamic (MHD) heliospheric models that rely on different strategies and assumptions. Until now only one paper has compared global heliosphere models, but without magnetic field effects. We comp...

The astropause (heliopause for the Sun) is the tangential discontinuity separating the stellar wind from the interstellar plasma. The global shape of the heliopause is a matter of debates. Two types of the shape are under discussion: comet-like and tube-like. In the second type the two-jets oriented toward the stellar rotation axis are formed by th...

In this paper, we search for the possible imprints of the secondary interstellar hydrogen atoms created at the heliospheric boundary in the full-sky maps of the hydrogen fluxes at the Earth orbit. By using our three-dimensional time-dependent kinetic model the maps of the hydrogen fluxes are calculated for different phases of the solar cycle and di...

Interstellar dust (ISD) penetrates into the heliosphere due to the relative motion of the Sun and the local interstellar medium (LISM). Inside the heliosphere and at the boundaries, where solar wind interacts with the LISM, distribution of ISD is modified due to the action of the electromagnetic forces, the solar gravitation and the radiation press...

The heliosphere is the bubble formed by the solar wind as it interacts with the interstellar medium (ISM). Studies show that the solar magnetic field funnels the heliosheath solar wind (the shocked solar wind at the edge of the heliosphere) into two jet-like structures1-2. Magnetohydrodynamic simulations show that these heliospheric jets become uns...

The global shape of the heliopause - the tangential discontinuity separating the solar wind from interstellar plasma - is a matter of recent hot debates. Two types of the shape are under discussion: comet-like and tube-like. In the second type the two-jets oriented toward the solar rotation axis are formed by the action of azimuthal component of th...

The Interstellar Boundary Explorer (IBEX) has been measuring interstellar hydrogen fluxes at 1 AU since 2009. In this paper, we analyzed all available data obtained with the IBEX-Lo instrument at energies 11-41 eV by using our numerical kinetic model of the interstellar hydrogen distribution in the heliosphere. We performed a fitting of the data to...

In this paper we present the numerical modeling results of the problem of the hypersonic stellar wind interaction with fully ionized interstellar medium that moves with respect to the star with supersonic speed. This is the classical problem that has been firstly studied in 1970 by Baranov et al. [1] under the thin layer approximation. In this pape...

The Interstellar Boundary Explorer (IBEX) has been measuring fluxes of the Energetic Neutral Atoms (ENAs) using the IBEX-Hi (0.3 -- 6 keV) instrument since 2008. We have developed a numerical time-depended code to calculate globally distributed flux (GDF) of hydrogen ENAs employing both 1) 3D kinetic-MHD model of the global heliosphere and 2) recon...

The interstellar boundary explorer (IBEX) has been measuring fluxes of the energetic neutral atoms (ENAs) using the IBEX-Hi (0.3–6 keV) instrument since 2008. We have developed a numerical time-depended code to calculate globally distributed flux (GDF) of hydrogen ENAs employing both (1) 3D kinetic-MHD model of the global heliosphere and (2) recons...

In this Letter, we provide constraints on the direction and magnitude of the pristine (i.e., unperturbed by the interaction with the Sun) local interstellar magnetic field. The constraints are based on analysis of the interstellar magnetic field components at the heliopause measured by magnetometer instruments on board Voyager 1 and 2 spacecraft. T...

In this Letter, we provide constraints on the direction and magnitude of the pristine (i.e., unperturbed by the interaction with the Sun) local interstellar magnetic field. The constraints are based on analysis of the interstellar magnetic field components at the heliopause measured by magnetometer instruments on board Voyager 1 and 2 spacecraft. T...

Interstellar dust penetrates into the heliosphere/astrosphere due to relative motion of the Sun and the local interstellar medium (LISM). Inside the heliosphere/astrosphere and at the heliospheric boundaries, where the solar/stellar wind interacts with LISM, distribution of the interstellar dust is modified due to an action of electromagnetic force...

In this paper we consider the distribution of interstellar dust in the vicinity of a star under the influence of stellar gravitation and radiation pressure. This study is applicable to stars with relatively weak stellar wind and strong radiation, when the stellar radiation has swept out the interstellar dust much further from the star than the posi...

Solar wind — a plasma stream flowing out of the solar corona — is interesting both as a carrier of solar activity and as an example of a collisionless plasma. We present the main results of Russian studies in recent years. The original MHD model allows interpreting the bifurcation of the heliospheric current sheet during maximum activity years as o...

In this paper we consider the distribution of the interstellar dust in the vicinity of the star under an influence of the stellar gravitation and radiation pressure. This study is applicable to the stars with relatively weak stellar wind and strong radiation, when the stellar radiation swept out the interstellar dust much further from the star than...

The Earth's hydrogen exosphere Lyman‐α radiation was mapped with the Solar Wind Anisotropies/Solar and Heliospheric Observatory (SWAN/SOHO) instrument in January 1996, 1997, and 1998 (low solar activity). The use of a hydrogen absorption cell allowed to disentangle the interplanetary emission from the geocoronal one and to assign the absorbed signa...

In this work we study the temporal and latitudinal variations of the solar wind mass flux at 1 AU derived from SOHO/SWAN data on backscattered solar Lyman-\(\alpha \) radiation in 1996 – 2018. Previously Katushkina et al. (J. Geophys. Res. 118, 2800, 2013) have shown that the latitudinal profiles of the solar wind mass flux during the solar maximum...

We consider the effect of the solar/stellar wind collimation towards the solar/stellar wind rotation axis in the heliosheath between the termination shock and the heliopause/astropause. The collimation is due to the magnetic force produced by the toroidal component of the solar/stellar magnetic field. The collimation leads to formation of a two-jet...

Quantitative analysis of the interstellar heavy (oxygen and neon) atom fluxes obtained by the Interstellar Boundary Explorer (IBEX) suggests the existence of the secondary interstellar oxygen component. This component is formed near the heliopause due to charge exchange of interstellar oxygen ions with hydrogen atoms, as was predicted theoretically...

In this work, we present for the first time the Lyman $\alpha$ intensities measured by Voyager 1/UVS in 2003-2014 (at 90-130 AU from the Sun). During this period Voyager 1 measured the Lyman $\alpha$ emission in the outer heliosphere at an almost fixed direction close to the upwind (that is towards the interstellar flow). The data show an unexpecte...

In this work, we present for the first time the Lyman $\alpha$ intensities measured by Voyager 1/UVS in 2003-2014 (at 90-130 AU from the Sun). During this period Voyager 1 measured the Lyman $\alpha$ emission in the outer heliosphere at an almost fixed direction close to the upwind (that is towards the interstellar flow). The data show an unexpecte...

High-resolution mid-infrared observations carried out by the Spitzer Space Telescope allowed one to resolve the fine structure of many astrospheres. In particular, they showed that the astrosphere around the B0.7 Ia star kappa Cas (HD 2905) has a clear-cut arc structure with numerous cirrus-like filaments beyond it. Previously, we suggested a physi...

This paper is a brief overview of research into the interaction between the solar wind and local interstellar medium. This interaction determines the global structure of the heliosphere (the region occupied by the solar wind) and has a complex multicomponent character. We describe the three-dimensional kinetic-magnetohydrodynamic model of the inter...

The interstellar neutral (ISN) oxygen atoms penetrate into the heliosphere from the Local Interstellar Medium (LISM). Oxygen atoms that directly penetrate into the heliosphere are called primary, while secondary oxygen population is formed near the heliopause due to the process of charge exchange of interstellar oxygen ions with hydrogen atoms and...

In the present paper we consider the steady flow produced by the hypersonic magnetized spherical source into the steady unmagnetized medium. The magnetic field of the source is considered purely azimuthal. The basic dimensionless parameter of the problem is Alfvén number at the inflow boundary at the source equatorial plane, which we denote as ε. W...

High-resolution mid-infrared observations of astrospheres show that many of them have filamentary (cirrus-like) structure. Using numerical models of dust dynamics in astrospheres, we suggest that their filamentary structure might be related to specific spatial distribution of the interstellar dust around the stars, caused by a gyrorotation of charg...

Opher et al. (2015), Drake et al. (2015) have shown that the heliospheric magnetic field results in formation of two-jet structure of the solar wind flow in the inner heliosheath, i.e. in the subsonic region between the heliospheric termination shock and the heliopause. In this scenario the heliopause has a tube-like topology as compared with a she...

Opher et al. (2015), Drake et al. (2015) have shown that the heliospheric magnetic field results in formation of two-jet structure of the solar wind flow in the inner heliosheath, i.e. in the subsonic region between the heliospheric termination shock and the heliopause. In this scenario the heliopause has a tube-like topology as compared with a she...

We developed a numerical model of the interstellar dust distribution in the global heliosphere including the heliospheric interface, where the solar wind plasma interacts with the local interstellar plasma. The model is based on the plasma distributions obtained by the 3D kinetic-MHD model of the heliospheric interface developed by Izmodenov & Alex...

Fluxes of energetic protons in the range from 30 keV up to several MeV measured at the Voyager 1/2 spacecraft downstream of the heliospheric termination shock can be explained by shock-drift acceleration theory, which includes variations of the magnetic field direction in a vicinity of the shock. The variations can be connected with the sector stru...

We perform a new analysis of the Lyman-alpha data obtained by Voyager 1 during the spatial scans in 1993-2003 while Voyager 1 was at 53-88 AU from the Sun. These data are the important source of information on the hydrogen distribution in the outer heliosphere. A sophisticated global kinetic-MHD model of the heliospheric interface and radiative tra...

The Interstellar Boundary Explorer (IBEX) has been directly observing neutral atoms from the local interstellar medium for the last six years (2009-2014). This paper ties together the 14 studies in this Astrophysical Journal Supplement Series Special Issue, which collectively describe the IBEX interstellar neutral results from this epoch and provid...

This paper provides a detailed description of the latest version of our model of the solar wind (SW) interaction with the local interstellar medium (LISM). This model has already been applied to the analysis of Lyman-alpha absorption spectra toward nearby stars and for analyses of Solar and Heliospheric Observatory/SWAN data. Katushkina et al. (thi...