2,269 research outputs found

    Spectral Statistics and Luminosity Function of a Hard X-ray Complete Sample of Brightest AGNs

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    We investigated the statistics of the X-ray spectral properties of a complete flux-limited sample of bright AGNs from HEAO-1 all-sky catalogs to provide the bright end constraint of the evolution of AGN hard X-ray luminosity function (HXLF) and the AGN population synthesis model of the X-ray background. Spectral studies have been made using ASCA and XMM-Newton observation data for almost all AGNs in this sample.Comment: PTPTex v0.88, 2 pages with 4 figures, Proceedings of the "Stellar-Mass, Intermediate -Masss, and Supermassive Black Holes" in Kyoto, Japa

    Spectral Statistics and Local Luminosity Function of a Hard X-ray Complete Sample of Brightest AGNs

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    We have measured the X-ray spectral properties of a complete flux-limited sample of bright AGNs from HEAO-1 all-sky catalogs to investigate their statistics and provide greater constraints on the bright-end of the hard X-ray luminosity function (HXLF) of AGNs and the AGN population synthesis model of the X-ray background. Spectral studies using data from ASCA, XMM-Newton and/or Beppo-SAX observations have been made for almost all AGNs in this sample. The spectral measurements enable us to construct the neutral absorbing column density (Log nH) distribution and separate HXLFs for absorbed (Log nH[cm-2]> 21.5) and unabsorbed AGNs in the local universe. Our results show evidence for a difference in the shapes of HXLFs of absorbed and unabsorbed AGNs in that absorbed AGN HXLF drops more rapidly at higher luminosities than that of unabsorbed AGNs, which is similar to that previously reported. In the Lx - nH plot, we found no AGN in the high-luminosity high-intrinsic absorption regime (Log Lx[erg/s]> 44.5, Log nH[cm-2]> 21.5) in our sample, where we expect about 5 AGNs if we assume that absorbed and unabsorbed having identical AGN HXLF shapes. We also find that the observed flux with ASCA or XMM-Newton is smaller than that with HEAO-1 by a factor of 0.29 on average, which is expected for re-observation of sources with a factor 2.5 variability amplitude scale.Comment: 43 pages(one column), 10 figures(5 electronic only figures have been included in the preprint source (tar.gz file)), accepted by The Astronomical Journal, 9. Mar 200

    Metabolic phenotyping of genetically diverged species in Gramineae

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    Early stage scaling in phase ordering kinetics

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    A global analysis of the scaling behaviour of a system with a scalar order parameter quenched to zero temperature is obtained by numerical simulation of the Ginzburg-Landau equation with conserved and non conserved order parameter. A rich structure emerges, characterized by early and asymptotic scaling regimes, separated by a crossover. The interplay among different dynamical behaviours is investigated by varying the parameters of the quench and can be interpreted as due to the competition of different dynamical fixed points.Comment: 21 pages, latex, 7 figures available upon request from [email protected]
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