http://dspace.nbuv.gov.ua:80/handle/123456789/114711 2026-04-15T05:00:34Z http://dspace.nbuv.gov.ua:80/handle/123456789/119937 A quasar sample for the Lyα forest studies from the Data Release 10 of the Sloan Digital Sky Survey Torbaniuk, O. We present a new sample of the z ≥ 2 quasar spectra. It contains 102 643 spectra which were visually selected from the SDSS DR10, and includes also a subsample of 65 976 spectra for the composite spectra compilation. This sample will be used for the Lyα forest studies, and can be used for other studies, including those of the quasar spectral properties and the spatial distribution of quasars at z > 2. The compiled composite spectra will be used for the determination of the intrinsic spectrum in the Lyα forest studies. Those objects which were not included into the main sample and rejected during the visual examination, are 11 192 quasars with the broad absorption lines, 6 804 spectra with the damped Lyα systems, 1 248 and 493 spectra with the absorption in the Lyα and Lyβ lines, respectively. The "non-quasar" objects, including 191 candidates for blazars and 30 galaxies with starburst, as well as 617 quasar spectra with wrong redshift, 417 incomplete spectra and 1 497 spectra with low S/N ratio, were also excluded. 2015-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/119936 The luminosity - spectral index dependence of the X-ray bright Seyfert galaxies Sadova, V.A.; Tugay, A.V. X-ray luminosities and spectral indices of 97 bright Seyfert 1 (Sy1) galaxies from the XMM-Newton archive are analysed in this article. Distribution of these values is random, so we conclude that the model of emission should be at least two-parametric. Within the framework of the merging model of active galactic nuclei (AGN), the relation between black hole mass, stage of merging and observable X-ray parameters is roposed. 2015-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/119935 Cyclic Period Changes of β Lyrae-type Eclipsing Variable Stars KR Cyg, V382 Cyg and BX And Tvardovskyi, D.E.; Marsakova, V.I. We have studied three binary stellar systems KR Cyg, V382 Cyg and BX And, which are eclipsing variables of the β Lyrae - type. We have studied the phase curves and O-C curves. The forms of their O-C curves are sinusoidal with a trend, so we made the conclusion that the periods of binary systems change periodically and we suppose that the systems have third components that do not take part in the eclipses, but produce a periodic "light time" effect, as the inner eclipsing binary rotates around the common centre of masses of the triple system. For the analysis, we used data published in the AAVSO and NSVS databases, as well as our own observations. For the O-C curves, the data were taken from the BRNO database, as well as from our own calculations of the moments of minima from the light curves. We determined secondary periods, calculated the minimal masses of the third components, estimated the mass transfer rate for the system V382 Cyg and corrected the ephemeris for these three eclipsing variables. 2015-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/119934 Magnetosheath and solar wind turbulence processes features identification Prokhorenkov, A.S.; Kozak, L.V.; Lui, A.T.Y. A different kind of analysis should be applied to a turbulent process, than that applied to a nondisturbed medium. In this work we present the result of extended self-similarity analysis (ESS) by comparing between different turbulent models: Kolmogorov K41 model, She-Leveque (isotropic log-Poisson model) of order 3; Iroshnikov-Kraichnan model and Politano-Pouquet model of order 4. Two regimes were observed for large and small times ales: the Gaussian distribution was used for small times ales for magnetic field fluctuation probability distribution function (PDF), and the Lèvy distribution was used for large-scale timescale non-Gaussian distributions. The intersection of two asymptotes corresponds to approximately 1 s, which agrees with the ion-cyclotron period. 2015-01-01T00:00:00Z