arXiv subjects

V. N. Oraevsky

Publications and source records attributed to V. N. Oraevsky.

6 recordsLinked to original sources

arXiv2003

The Peculiarities of the Interaction of Phobos with the Solar Wind are Evidence of the Phobos Magnetic Obstacle (from Phobos-2 Data)

Using magnetic field and plasma data acquired during "Phobos-2" mission in regions which have not been explored before, we study the solar wind interaction with Phobos. The draping magnetic field of the solar wind around Phobos appears at distances of 200-300 km from the Phobos day-side due to a density and magnetic field pile up in front of the Phobos obstacle. The nature of the interaction and the magnetic field signatures observed are consistent with the ratio of the proton skin depth to the actual size of the Phobos obstacle to the solar wind. Phobos deflects the flow of the solar wind and the subsolar stand-off distance of the deflection is about 16-17 Phobos radii. Source with equivalent magnetic moment M'=10^{15} A m^2 in Phobos leads to the development of such an obstacle to solar wind flow around Phobos. These data give a lesson for the study of the interaction of the small, magnetized object with solar wind.

physics.space-ph↗

arXiv2002

In Situ Measurements of the Phobos Magnetic Field During the Phobos-2 Mission

In this communication, we examine in situ observations of the magnetic field in the vicinity of Phobos on the "Phobos-2" mission and give some analysis of the data during a unique experiment ``Celestial Mechanics,'' which leads to the support of evidence of the Phobos magnetic field. In particular, it is suggested that the peculiarity of the solar wind interaction with Phobos and rotating direction of the magnetic field obtained on the circular orbits around Mars are the evidence for the existence of an intrinsic planetary field of Phobos.

physics.space-ph↗

arXiv2002

Spin waves in the magnetized plasma of a supernova and its excitation by neutrino fluxes

The spin effects on electromagnetic waves in a strongly magnetized plasma with rare collisions is considered with the help of relativistic kinetic equations, which takes into account the electron spin dynamics in the selfconsistent electric and magnetic fields. It is shown that for electromagnetic waves propagating almost perpendicular to ambient magnetic field the spin effects become essential in the vicinity of electron gyrofrequency and the corresponding wave dispersion and growth rate of the electromagnetic spin waves in the presence of intense quasi monoenergetic fluxes of neutrino is determined.

hep-ph↗

arXiv2002

Neutrino kinetics in a magnetized dense plasma

The relativistic kinetic equations (RKE) for lepton plasma in the presence of a strong external magnetic field are derived in Vlasov approximation. The new RKE for the electron spin distribution function includes the weak interaction with neutrinos originated by the axial vector current ($\sim c_A$) and provided by the parity nonconservation. In a polarized electron gas Bloch equation describing the evolution of the magnetization density perturbation is derived from the electron spin RKE being modified in the presence of neutrino fluxes. Such modified hydrodynamical equation allows to obtain the new dispersion equation in a magnetized plasma from which the neutrino driven instability of spin waves can be found. It is shown that this instability is more efficient e.g. in a magnetized supernova than the analogous one for Langmuir waves enhanced in an isotropic plasma.

hep-ph↗

arXiv2002

Eigenoscillations of the Differentially Rotating Sun: I. 22-year, 4000-year, and quasi-biennial modes

Retrograde waves with frequencies much lower than the rotation frequency become trapped in the solar radiative interior. The eigenfunctions of the compressible, nonadiabatic, Rossby-like modes ($ε$-mechanism and radiative losses taken into account) are obtained by an asymptotic method assuming a very small latitudinal gradient of rotation, without an arbitrary choice of other free parameters. An integral dispersion relation for the complex eigenfrequencies is derived as a solution of the boundary value problem. The discovered resonant cavity modes (called R-modes) are fundamentally different from the known r-modes: their frequencies are functions of the solar interior structure, and the reason for their existence is not related to geometrical effects. The most unstable R-modes are those with periods of 1--3 yr, 18--30 yr, and 1500--20000 yrs; these three separate period ranges are known from solar and geophysical data. The growing times of those modes which are unstable with respect to the $ε$-mechanism are $\approx 10^2, 10^3,$ and $10^5$ years, respectively. The amplitudes of the R-modes are growing towards the center of the Sun. We discuss some prospects to develop the theory of R-modes as a driver of the dynamics in the convective zone which could explain, e.g., observed short-term fluctuations of rotation, a control of the solar magnetic cycle, and abrupt changes of terrestrial climate in the past.

astro-ph↗

arXiv2001

Alfven Wave Generation by means of High Orbital Injection of Barium Cloud in Magnetosphere

An analysis of the Alfven wave generation associated with the barium vapor release at altitudes ~ 5.2 Earth's radii (ER) in the magnetosphere is presented. Such injections were executed in G-8 and G-10 experiments of the Combined Radiation and Radiation Effects Satellite (CRRES) mission. It is shown that the generation of Alfven waves is possible during the total time of plasma expansion. The maximum intensity of these waves corresponds to the time of complete retardation of the diamagnetic cavity created by the expansion of plasma cloud. The Alfven wave exhibits a form of an impulse with an effective frequency ~ 0.03-0.05 Hz. Due to the background conditions and wave frequency, the wave mainly oscillates along the geomagnetic field between the mirror reflection points situated at ~ 0.7 ER. The wave amplitude is sufficient to the generation of plasma instabilities and longitudinal electric field, and to an increase in the longitudinal energy of electrons to ~ 1 keV. These processes are the most probable for altitudes ~ 1 ER. The auroral kilometric radiation (AKR) at frequencies ~ 100 kHz is associated with these accelerated electrons. The acceleration of electrons and AKR can be observed almost continuously during the first minute and then from time to time with pauses about 35-40 s till 6-8 min after the release. The betatron acceleration of electrons at the recovery of the geomagnetic field is also discussed. This mechanism could be responsible for the acceleration of electrons resulting in the aurorae and ultra short radio wave storm at frequencies 50-300 MHz observed at the 8-10th min after the release.

physics.space-ph↗