422 research outputs found

    Origin of Correlations between Central Black Holes Masses and Galactic Bulge Velocity Dispersions

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    We argue that the observed correlations between central black holes masses M_{BH} and galactic bulge velocity dispersions \sigma_e in the form M_{BH}\propto\sigma_e^4 may witness on the pregalactic origin of massive black holes. Primordial black holes would be the centers for growing protogalaxies which experienced multiple mergers with ordinary galaxies. This process is accompanied by the merging of black holes in the galactic nuclei.Comment: 6 pages, 1 figure, submitted to Astron. and Astrophys. Transaction

    Weather data errors analysis in solar power stations generation forecasting

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    The paper presents a short-term forecasting model for solar power stations (SPS) generation developed by the authors. This model is based on weather data and built into the existing software product as a separate short-term forecasting module for the SPS generation. The main problems associated with forecasting the SPS generation on cloudy days were revealed in the framework of authors' research, which is due not to the error of the developed model but to the use of the same learning sample for both solar and cloudy days. This paper contains analysis of the main problems related to the learning sampling, samples pattern, quality and representativeness for forecasting the SPS generation on cloudy days. Besides, the paper includes a calculation example performed for the existing SPS and a detailed analysis of the forecast generation on cloudy days based on the actual weather provider data. © The Authors, published by EDP Sciences

    Solar activity beyond the disk and variations of the cosmic ray gradient

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    Part of galactic cosmic rays (CR) observed near the Earth and on the Earth come from beyond-disk regions of circumsolar space. But CR of those energies which undergo substantial modulation cover too large a path across the lines of force of the interplanetary magnetic field (IMF) in order that they could provide an effective transfer of information about beyond-disk solar activity. And if it is still possible, the most probable channel for transferring such information must be a neutral layer of heliomagnetosphere in which the transverse CR transport is facilitated by their drift in an inhomogeneous magnetic field. A simple diffusion model for an expected CR variation in a neutral layer near the Earth is discussed. It is of importance that variations of the CR gradient are not at all always accompanied by considerable variations of IMF and solar wind velocity at the point of observation

    Siting and sizing of distributed generation with integrated project feasibility analysis

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    Научно-исследовательская работа выполнена по договору № 1.2.1.5./10 от 27 мая 2013 г. В ходе выполнения была разработана методика оценки целесообразности строительства объекта малой генерации, позволяющая качественно и количественно оценить влияние генерирующего источника на энергосистему, а также оценить опти-мальную точку подключения и мощность генерирующего источника в соответствии с перечнем разработанных технико-экономических критериев.The research work was carried out under contract № 1.2.1.5./10 of 27 May 2013. The final report contains the detailed description of the methodology, developed for distributed generation implementation feasibility assessment. Proposed approach makes it possible to provide quantitative and qualitative assessment of distributed generation influence on the power system, as well as to assess the optimal point of power generation unit connection in accordance with the list of technical and economic criteria.Программа развития УрФУ на 2013 год (п.1.2.2.3

    Remnants of dark matter clumps

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    What happened to the central cores of tidally destructed dark matter clumps in the Galactic halo? We calculate the probability of surviving of the remnants of dark matter clumps in the Galaxy by modelling the tidal destruction of the small-scale clumps. It is demonstrated that a substantial fraction of clump remnants may survive through the tidal destruction during the lifetime of the Galaxy if the radius of a core is rather small. The resulting mass spectrum of survived clumps is extended down to the mass of the core of the cosmologically produced clumps with a minimal mass. Since the annihilation signal is dominated by the dense part of the core, destruction of the outer part of the clump affects the annihilation rate relatively weakly and the survived dense remnants of tidally destructed clumps provide a large contribution to the annihilation signal in the Galaxy. The uncertainties in minimal clump mass resulting from the uncertainties in neutralino models are discussed.Comment: 13 pages, 6 figures, added reference
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