Investigation of the Earth Ionosphere using the Radio Emission of Pulsars

The investigation of the Earth ionosphere both in a quiet and a disturbed states is still desirable. Despite recent progress in its modeling and in estimating the electron concentration along the line of sight by GPS signals, the impact of the disturbed ionosphere and magnetic field on the wave propagation still remains not sufficiently understood. This is due to lack of information on the polarization of GPS signals, and due to poorly conditioned models of the ionosphere at high altitudes and strong perturbations. In this article we consider a possibility of using the data of pulsar radio emission, along with the traditional GPS system data, for the vertical and oblique sounding of the ionosphere. This approach also allows to monitor parameters of the propagation medium, such as the dispersion measure and the rotation measure using changes of the polarization between pulses. By using a selected pulsar constellation it is possible to increase the number of directions in which parameters of the ionosphere and the magnetic field can be estimated.Comment: 13 pages, 4 figures, Baltic Astronomy, vol.22, 53-65, 201

Tunnelling series in terms of perturbation theory for quantum spin systems

Considered is quantum tunnelling in anisotropic spin systems in a magnetic field perpendicular to the anisotropy axis. In the domain of small field the problem of calculating tunnelling splitting of energy levels is reduced to constructing the perturbatio n series with degeneracy, the order of degeneracy being proportional to a spin value. Partial summation of this series taking into account ''dangerous terms'' with small denominators is performed and the value of tunnelling splitting is calculated with allowance for the first correction with respect to a magnetic field.Comment: 7 pages, REVTeX 3.

Some evolutionary aspects of the binary stellar systems containing neutron star

The obvious lack of the binary stellar systems that contain neutron stars (NS) is observed at present. Partly it is caused by the fact that it is very difficult to detect neutron star in a binary system if this relativistic component does not manifest itself as a radio pulsar. Among 1879 pulsars that are listed in the ATNF pulsar catalogue, only 141 pulsars are known to be the companions in binary systems. Only 81 objects having median mass estimation of more than 0.2 $M_{\odot}$ constitute the binary systems with pulsars. Nevertheless, such systems should be much more numerous and their investigation is of the great interest because thier structure and evolution can certainly help in our understanding of many unique properties that are seen in some stars.Comment: Accepted to published in the Odessa Astronomical Publications, 2012, vol. 25/1, p.35-3

Some Statistical Picture of Magnetic CP Stars Evolution

We discuss some statistical results on the evolution of magnetic CP stars in the framework of the supposition about their binary nature.Comment: 3 pages, 3 figure

Petrology and classification of new Antarctic carbonaceous chondrites PCA-91082, TIL-91722 and WIS-91600

Three Antarctic chondrites : Pecora Escarpment (PCA) 91082,Thiel Mountains (TIL) 91722 and Wisconsin Range (WIS) 91600 were studied by SEMEDS methods and classified as CR2,CV3 and CM2,respectively. PCA91082 and TIL91722 contain rare fine-grained refractory inclusions and amoeboid olivine aggregates without any traces of secondary alteration processes. Chondrule pyroxene is enriched in Cr and Mn compared to pyroxenes from refractory inclusions. Presence of Cr^ and Ti^ with normal Cr^ and Ti^ in chondrule pyroxenes probably indicates reducing conditions during chondrule formation. Several unusual objects, such as a compound P-rich chondrule in PCA91082,and P and Cr enriched glasses in WIS91600,were studied. The metal fraction of PCA91082 shows a positive Nivs. Co trend which can be produced by volatilization process. Bulk composition of inclusions and chondrules follows to condensation trend, but exsolution structures and glasses indicate crystallization from melts