Quantum nature of cyclotron harmonics in thermal spectra of neutron stars

Some isolated neutron stars show harmonically spaced absorption features in their thermal soft X-ray spectra. The interpretation of the features as a cyclotron line and its harmonics has been suggested, but the usual explanation of the harmonics as caused by relativistic effects fails because the relativistic corrections are extremely small in this case. We suggest that the features correspond to the peaks in the energy dependence of the free-free opacity in a quantizing magnetic field, known as quantum oscillations. The peaks arise when the transitions to new Landau levels become allowed with increasing the photon energy; they are strongly enhanced by the square-root singularities in the phase-space density of quantum states in the case when the free (non-quantized) motion is effectively one-dimensional. To explore observable properties of these quantum oscillations, we calculate models of hydrogen neutron star atmospheres with B \sim 10^{10} - 10^{11} G (i.e., electron cyclotron energy E_{c,e} = 0.1 - 1 keV) and T_{eff} = 1 - 3 MK. Such conditions are thought to be typical for the so-called central compact objects in supernova remnants, such as 1E 1207.4-5209 in PKS 1209-51/52. We show that observable features at the electron cyclotron harmonics form at moderately large values of the quantization parameter, b_{eff} = E_{c,e}/kT_{eff} = 0.5 - 20. The equivalent widths of the features can reach 100 - 200 eV; they grow with increasing b_{eff} and are lower for higher harmonics.Comment: 6 pages; shortened, references updated; published in Ap

On a Nonlocal Ostrovsky-Whitham Type Dynamical System, Its Riemann Type Inhomogeneous Regularizations and Their Integrability

Short-wave perturbations in a relaxing medium, governed by a special reduction of the Ostrovsky evolution equation, and later derived by Whitham, are studied using the gradient-holonomic integrability algorithm. The bi-Hamiltonicity and complete integrability of the corresponding dynamical system is stated and an infinite hierarchy of commuting to each other conservation laws of dispersive type are found. The well defined regularization of the model is constructed and its Lax type integrability is discussed. A generalized hydrodynamical Riemann type system is considered, infinite hierarchies of conservation laws, related compatible Poisson structures and a Lax type representation for the special case N=3 are constructed

Seasonal and long-term sea level variability in the marginal seas of the Arctic Ocean

One of the parameters useful for monitoring large-scale climate variability in the Arctic Ocean is sea level. It integrates virtually all static and dynamic processes in the hydrosphere and atmosphere of the Arctic. Previously unavailable mean monthly sea level data at 44 coastal and island stations in the Kara, Laptev, East Siberian and Chukchi seas covering years from 1950 to 1990 were used to analyse seasonal and inter-annual variability. Sea level has a significant annual cycle with an average seasonal amplitude (from peak to peak) in the coastal zone of the Arctic seas on the order of 20 - 30 cm. The analysis of inter-annual and inter-decadal changes has shown that at nearly all stations in the Kara, Laptev, East Siberian and Chukchi seas from the beginning of the 1950s through the end of 1980s there is a positive trend in sea level variability. The main contribution to the sea level rise was in the 1980s; on average for the coastal zone of Siberian shelf the sea level in the 1980s was 5 - 6 cm higher than in the previous decades. A reasonable agreement between observed decadal mean sea level values and the results of diagnostic model simulations suggests that this rise in the Arctic seas is connected with the reorganization of large-scale circulation of the Arctic Ocean, rather than the regional lowering of the coasts, as has been suggested previously

Analysis of realization of regional industrial policy in the former Soviet Union: problems and prospects

АНАЛИЗ РЕАЛИЗАЦИИ РЕГИОНАЛЬНОЙ ПРОМЫШЛЕННОЙ ПОЛИТИКИ НА ПОСТСОВЕТСКОМ ПРОСТРАНСТВЕ: ПРОБЛЕМЫ И ПЕРСПЕКТИВЫ д-р экон. наук, проф. В.К. ПАВЛОВ (Ижевский филиал Российского университета кооперации, Россия); д-р экон. наук, проф. О.В. НОСОВА (Харьковский учебно-научный институт университета банковского дела, Украина)The article is devoted to a research of a role of industrial policy in regional development and contains a list of the main measures for carrying out structural transformations in the former Soviet Union. The theoretical analysis of variety of approaches confirms the existence of unfair competition and proves the necessity of further empirical researches for assessment of efficiency of industrial policy. Use of complexity, limited rationality and social and economic dynamics provides application of cross-disciplinary approach. Process of reforming in regions depends on success of industrial policy which includes use of various measures, in particular, of support of national producers (granting subsidies, applications of protectionism in various branches and others). Researches of interrelation of trade and economic growth demonstrate the existence of correlation between growth rates of trade and indicators of an economic environment in regions. The assessment of regional imbalances is defined by indicators of a gross regional product per capita, regional employment and expenses for education.= Исследуется роль промышленной политики в региональном развитии. Представлен перечень основных мер для проведения структурных преобразований на постсоветском пространстве. Теоретический анализ многообразия подходов подтверждает существование недобросовестной конкуренции и обосновывает необходимость дальнейших эмпирических исследований для оценки эффективности промышленной политики. Использование комплексности, ограниченной рациональности и социально-экономической динамики предусматривает применение междисциплинарного подхода. Показано, что процесс реформирования в регионах зависит от успеха промышленной политики, которая включает использование различных мер, в частности поддержки национальных производителей (предоставление субсидий, применения политики протекционизма в различных отраслях и другие). Исследования взаимосвязи торговли и экономического роста свидетельствуют о существовании корреляции между темпами роста торговли и показателями экономической конъюнктуры в регионах. Оценка региональных дисбалансов определяется показателями валового регионального продукта в расчете на душу населения, региональной занятости и расходами на образование

Channeling of electrons and positrons in straight and periodically bent diamond(110) crystals

In this paper we present the results of a systematic numerical analysis of the channeling properties of electrons and positrons in oriented straight and periodically bent diamond(110) crystals. We analyse dependence of the intensity of the radiation emitted on the projectile energy as well as on the bending amplitude. The analysis presented is based on the grounds of accurate numerical simulations of the channeling process. The simulation parameters, such as the crystal orientation, thickness and bending parameters of the crystals as well as the energy of the projectiles, were chosen to match those used in past and ongoing experiments. The peculiarities which appear in the radiation spectra are attributed to the interplay of various radiation mechanisms. The analysis performed can be used to predict and explain future experimental results.Comment: 14 pages, 8 figures, 1 tabl