Structure of sporadic meteor radiant distributions from radar observations

An analysis of sporadic meteor flux distributions over the celestial sphere is given. Symmetry of the radiant distribution relative to the plane crossing the ecliptic pole and the Earth's apex and antapex was identified.     

Modelling of neutral-gas releases into the earth's ionosphere

This paper discusses a mathematical model which is aimed at the interpretation of the effects by injections of chemically active gases into the ionosphere. A study is made of neutral-gas expansion processes as well as of processes associated with the formation of decreased plasma density regions, ionospheric holes. The spatial-temporal distribution of particles released during the transition to the diffusion regime is constructed using an approximate, analytic solution of the Boltzmann equation with the collision integral in the form of BGK, with proper allowance for gravitation and atmospheric inhomogeneity. The investigation of processes associated with the formation of ionospheric holes is carried out using a numerical model of ionosphere-plasmasphere coupling, in which the transfer equations for charged components are integrated along geomagnetic field lines. The purpose of the model is to calculate the electron density and temperature, ion composition and emission of a disturbed region in the 6300 Å line at ionospheric and plasmaspheric heights.     

Boundaries of intergrowths between mineral individuals: A zone of secondary mineral formation in aggregates

Intergrowth boundaries between mineral individuals in dunite of the Gal’moenan massif in Koryakia was studied in terms of crystal morphology, crystal optics, and ontogenesis. The results obtained allowed us to trace the staged formation of olivine and chromite and four generations of these minerals. Micro-and nanotopography of boundary surfaces between intergrown mineral individuals of different generations was examined with optic, electron, and atomic force microscopes. The boundaries between mineral individuals of different generations are distinguished by their microsculpture for both olivine and chromite grains. Both minerals demonstrate a compositional trend toward refinement from older to younger generations. The decrease in the iron mole fraction in olivine and chromite is accompanied by the crystallization of magnetite along weakened zones in olivine of the first generation and as outer rims around the chromite grains of the second generation observable under optic and electronic microscopes. The subsequent refinement of chromite results in the release of PGE from its lattice, as established by atomic power microscopy. The newly formed PGM are localized at the boundaries between mineral individuals and, thus, mark a special stage in the ontogenetic evolution of mineral aggregates. Further recrystallization is expressed in the spatial redistribution of grain boundaries and the formation of monomineralic intergrowth boundaries, i.e., the glomerogranular structure of rock and substructures of PGM, chromite, and olivine grains as intermediate types of organization of the granular assemblies in the form of reticulate, chain, and cellular structures and substructures of aggregates.     

First Data on Formation Conditions of the Zhilnoye Au–Ag Epithermal Gold Deposit (Eastern Chukotka,Russia)

The first data on study of individual fluid inclusions in the Zhilnoye deposit have been obtained. It has been found that the gold-bearing quartz veins of the deposit were formed by heterogeneous hydrothermal fluids with low salt concentrations (0.2–3.6 wt% equiv. NaCl under intermediate temperature conditions of 246–350°C). The fluid pressure was 80–160 bar corresponding to 0.3–0.6 km depths of formation under hydrostatic conditions. The parameters of the mineral-forming fluids of the Zhilnoye deposit correspond to typical parameters of the fluids of epithermal deposits.     

3D Doppler Tomography of the X-Ray Binary System Cygnus X-1 from Spectral Observations in 2007 in the HeII λ 4686 Å Line

The results of a 3D Doppler tomography analysis for the X-ray binary system Cyg X-1 in the HeII λ 4686 Å line are presented. Information about the motions of gaseous flows outside the orbital plane has been obtained for the first time. Line profiles obtained in June 2007 on the 2-m telescope of the Terskol Branch of the Institute of Astronomy (Russia) and on the 2.1-m telescope of the National Astronomical Observatory of Mexico were used. A detailed analysis of these spectral data is presented: the distribution of the data in time, distribution of orbital phases for the projections, comparison of the line profile shapes for the data from two observatories. The geometry of the total transfer function obtained in the reconstruction is considered. The possibility of applying the profiles obtained to realize 3D tomography is justified. The resolution of the constructed 3D tomogram in velocity space is 60 × 60 × 40 km/s for V _x , V _y , V _z . Fifteen cross sections for 15 different V _z values perpendicular to the orbital plane are presented. The intensity distributions corresponding to the velocities of gaseous structures in the binary system are obtained. The reconstruction was realized using the radio-astronomical approach, developed for solving problems in tomography with a limited number of projections.