Browsing by Subject "accretion"

Now showing 1 - 7 of 7
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    Exploring inside-out Doppler tomography: magnetic cataclysmic variables
    (2016) Kotze, E J; Potter, S B; McBride, V A
    Context. Doppler tomography of magnetic cataclysmic variables is a valuable tool for the interpretation of the complex spectroscopic emission line profiles observed for these systems.
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    Exploring inside-out Doppler tomography: non-magnetic cataclysmic variables
    (2015) Kotze, E J; Potter, S B; McBride, V A
    Context. Doppler tomography is a technique that has revolutionised the interpretation of the phase-resolved spectroscopic observations of interacting binary systems.
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    Implications of the HST/FGS parallaxof SS Cygnion the disc instability model
    (2002) Schreiber, M R; Gänsicke, B T
    We analyse the consequences of the recently measured parallax of SS Cygni (Harrison et al. 1999) on the accretion disc limit cycle model. Using the observed long term light curve of SS Cyg and d = 166 ± 12 pc, we obtain for the mean mass transfer rate M˙ tr = 4.2±1.7×1017 g s−1. In addition, we calculate the vertical structure of the accretion disc taking into account heating of the outer disc by the stream impact. Comparing the mean accretion rate derived from the observations with the calculated critical mass transfer rate, we find that the disc instability model disagrees with the observed long term light curve of SS Cyg as M˙ tr is greater or similar to the critical mass transfer rate. The failure of the model indicated by this result can be confirmed by considering that the accretion rate at the onset of the decline should be exactly equal to the value critical for stability. In contrast to this prediction of the model, we find that the accretion rate required to explain the observed visual magnitude at the onset of the decline must be significantly higher than the critical mass transfer rate. Our results strongly suggest that either the usually assumed temperature dependence of the viscosity parameter α is not a realistic description of the disc viscosity, that the mass transfer rate in
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    Irradiated accretion discs in post novae
    (2001) Schreiber, M R; Gänsicke, B T
    We derive approximations for the
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    Phase-resolved optical and X-ray spectroscopy of low-mass X-ray binary X1822–371
    (2012) Somero, A; Hakala, P; Muhli, P; Charles, P; Vilhu, O
    Context. X1822–371 is the prototypical accretion disc corona X-ray source, a low-mass X-ray binary viewed at very high inclination, thereby allowing the disc structure and extended disc coronal regions to be visible. As the brightest (closest) such source, X1822–371 is ideal for studying the shape and edge structure of an accretion disc, and comparing with detailed models.
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    SALT long-slit spectroscopy of CTS C30.10: two-component Mg II line
    (2014) Modzelewska, J; Czerny, B; Hryniewicz, K; Bilicki, M; Krupa, M; Świȩtoń, A; Pych, W; Udalski, A; Adhikari, T P; Petrogalli, F
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    Towards equation of state of dark energy from quasar monitoring: reverberation strategy
    (2013) Czerny, B; Hryniewicz, K; Maity, I; Schwarzenberg-Czerny, A; Życki, P T; Bilicki, M
    Context. High-redshift quasars can be used to constrain the equation of state of dark energy. They can serve as a complementary tool to supernovae Type Ia, especially at z > 1.