46 research outputs found

    An atlas of line profile studies for SU UMa type cataclysmic variables

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    We present H-alpha line-profile analyses for the seven SU UMa type dwarf novae AK Cnc, WX Cet, AQ Eri, VW Hyi, RZ Leo, TU Men, and HS Vir. All data sets are treated in the same manner, applying a sequence of techniques for each system. The basic ingredients of this sequence are the diagnostic diagram to determine the zero point of the orbital phase, and Doppler tomography to visualise the emission distribution. We furthermore introduce a new qualitative way of to evaluate the Doppler fit, by comparing the line profile of the reconstructed with the original spectrum in the form of the V/R plot. We present the results of the analysis in the compact form of an atlas, allowing a direct comparison of the emission distribution in our targets. Although most of the data sets were not taken with the intention of a line-profile analysis, we obtain significant results and are able to indicate the type of the additional emission in these systems. Our objects should have in principle very similar physical properties, i.e. they cover only a small range in orbital periods, mass ratios, and mass-transfer rates. Nevertheless, we find a large variety of phenomena both with respect to the individual systems and also within individual data sets of the same object. This includes `canonical' additional emission components from the secondary star and the bright spot, but also emission from the leading side of the accretion disc.Comment: 20 pages, 25 figures, accepted for publication in A&A, figures have been diminished in size and qualit

    Period changes in six semi-detached Algol-type binaries

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    Six semi-detached Algol-type binaries lacking a period analysis were chosen to test for a presence of a third body. The O-C diagrams of these binaries were analyzed with the least-squares method by using all available times of minima. Also fourteen new minima, obtained from our observations, were included in the present research. The light-time effect was adopted as a main factor for the detailed description of the long-term period changes. Third bodies were found with orbital periods from 46 up to 84 years, and eccentricities from 0.0 to 0.78 for the selected binaries. The mass functions and the minimal masses of such bodies were also calculated.Comment: 14 pages, 8 figure

    Elastic Scattering of Medium-Energy Protons

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    This work was supported by National Science Foundation Grant PHY 75-00289 and Indiana Universit

    The Optical Model Analysis of 200 MeV p + 16-O Elastic Scattering

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    This work was supported by the National Science Foundation Grant NSF PHY 81-14339 and by Indiana Universit

    Polarization in Medium-Energy Proton-Nucleus Elastic Scattering

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    This work was supported by National Science Foundation Grants PHY 76-84033A01, PHY 78-22774, and Indiana Universit

    The Optical Potential for Medium-Energy Proton Scattering

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    This work was supported by National Science Foundation Grant PHY 76-84033 and Indiana Universit

    V2051 Ophiuchi after superoutburst : out-of-plane material and the superhump light source

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    Aims. We performed a detailed spectroscopic analysis of the dwarf nova V2051 Oph at the end of its 1999 superoutburst. We studied and interpreted the simultaneous behaviour of various emission lines. Methods. We obtained high-resolution echelle spectroscopic data at ESO’s NTT with EMMI, covering the spectral range of 4000–7500 Å. The analysis was performed using standard IRAF tools. The indirect imaging technique of Doppler tomography was applied, in order to map the accretion disc and distinguish between the different emission sources. Results. The spectra are characterised by strong Balmer emission, together with lines of He i and the iron triplet Fe ii 42. All lines are double-peaked, but the blue-to-red peak strength and central absorption depth vary. The primary’s velocity was found to be 84.9 kms−1. The spectrograms of the emission lines reveal the prograde rotation of a disc-like emitting region and, for the Balmer and He i lines, an enhancement of the red-wing during eclipse indicates a bright spot origin. The modulation of the double-peak separation shows a highly asymmetric disc with non-uniform emissivity. This is confirmed by the Doppler maps, which apart from the disc and bright spot emission also indicate an additional region of enhanced emission in the 4th quadrant (+Vx, −Vy), which we associate with the superhump light source. Given the behaviour of the iron triplet and its distinct differences from the rest of the lines, we attribute its existence to an extended gas region above the disc. Its origin can be explained through the fluorescence mechanism

    Phenomenological and Microscopic Optical-Model Descriptions of 99 MeV 6-Li Scattering

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    This work was supported by National Science Foundation Grants PHY 76-84033A01, PHY 78-22774, and Indiana Universit

    Analyzing Powers for Deuteron-Induced Reactions Leading to Continuum Final States

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    This work was supported by the National Science Foundation Grant NSF PHY 78-22774 A02 & A03 and by Indiana Universit
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