843 resultados para Multi-centre study


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This paper forms part of Lukasz Mikolajczyk's PhD dissertation, which is supervised by Karen Milek

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Context. Since its launch, the X-ray and γ-ray observatory INTEGRAL satellite has revealed a new class of high-mass X-ray binaries (HMXB) displaying fast flares and hosting supergiant companion stars. Optical and infrared (OIR) observations in a multi-wavelength context are essential to understand the nature and evolution of these newly discovered celestial objects. Aims. The goal of this multiwavelength study (from ultraviolet to infrared) is to characterise the properties of IGR J16465−4507, to confirm its HMXB nature and that it hosts a supergiant star. Methods. We analysed all OIR, photometric and spectroscopic observations taken on this source, carried out at ESO facilities. Results. Using spectroscopic data, we constrained the spectral type of the companion star between B0.5 and B1 Ib, settling the debate on the true nature of this source. We measured a high rotation velocity of v = 320 ± 8km s-1 from fitting absorption and emission lines in a stellar spectral model. We then built a spectral energy distribution from photometric observations to evaluate the origin of the different components radiating at each energy range. Conclusions. We finally show that, having accurately determined the spectral type of the early-B supergiant in IGR J16465−4507, we firmly support its classification as an intermediate supergiant fast X-ray transient (SFXT).

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The regions of the Russian Federation are immensely diverse economically and geographically as well as when it comes to their national identity, civic awareness and political activity. We are in fact dealing with a ‘multi-speed Russia’: along with the post-industrial regions with their higher living standards and a need for pluralism in politics, there are poverty-stricken, inertial regions, dependent on subsidies from the centre. As a result of the policy of centralisation pursued by the Kremlin since 2000, the autonomy of the regions has been reduced fundamentally. This has affected the performance of the regional elites and made it difficult for the regions to use their natural advantages (such as resources or location) to their benefit. One of the effects of this policy has been the constantly decreasing number of the donor regions. The current model promotes the role of the region as a passive supplicant, for whom it is easier to seek support from the central government, offering loyalty in exchange, than to implement complex systemic reforms that would contribute to long-term development. Moscow’s control (political, economic and administrative) over the regions is currently so thorough that it contradicts the formally existing federal form of government in Russia.

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National Highway Traffic Safety Administration, Washington, D.C.

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"This condensation (SW-9c. 1)--is based on the Ralph Stone and Company, Inc., report by the same title."

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Bibliography: p. 57-59.

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"This report was prepared by University of Florida, Gainesville, Florida, under USAF Contract no. F 33615-67-C-1227."