The standstill luminosity in Z Cam systems |
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| Authors: | R Stehle A King C Rudge |
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| Institution: | Astronomy Group, University of Leicester, Leicester LE1 7RH |
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| Abstract: | We consider accretion discs in close binary systems. We show that the heating of a disc at the impact point of the accretion stream contributes significantly to the local energy budget at its outer edge. As a result, the thermal balance relation between local accretion rate and surface density (the 'S-curve') changes; the critical mass transfer rate above which no dwarf nova outbursts occur can be up to 40 per cent smaller than without impact heating. Standstills in Z Cam systems thus occur at smaller mass transfer rates than otherwise expected, and are fainter than the peak luminosity during the dwarf nova phase as a result. |
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| Keywords: | accretion accretion discs instabilities binaries: close novae cataclysmic variables |
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