Supersoft X-Ray Source CAL 83: A Possible AE Aqr-like System

Authors

  • A. Odendaal Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein, 9300, South Africa
  • P. J. Meintjes Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein, 9300, South Africa
  • P. A. Charles School of Physics and Astronomy, Southampton University, Southampton SO17 1BJ
  • A. F. Rajoelimanana Department of Physics, North-West University, Private Bag X2046, Mmabatho 2735, South Africa

DOI:

https://doi.org/10.14311/APP.2015.02.0094

Abstract

CAL83 is a close binary supersoft X-ray source in the Large Magellanic Cloud. A ~67 s periodicity detected in supersoft X-rays is most probably associated with the spin period of a highly spun-up white dwarf (WD). The variability in the period is ascribed to the obscuration of the WD by the hydrogen burning envelope surrounding it, rotating with a period that is close to, but not quite synchronized with, the WD rotation period. Optical spectra obtained with SALT exhibit accretion disc emission lines with broad wing structures and P Cyg profiles, indicating mass outflows. Timing analysis of photometrical observations performed at the South African Astronomical Observatory (SAAO) revealed variable signals at ≤1 mHz which are thought to be associated with quasi-periodic oscillations from an accretion disc. The short spin period inferred for CAL83 can be the result of spin-up by accretion disc torques during a long mass transfer history, placing this source on a similar evolutionary track as the cataclysmic variable AE Aqr.

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Published

2015-02-23

Issue

Vol. 2 No. 1 (2015): THE GOLDEN AGE OF CATACLYSMIC VARIABLES AND RELATED OBJECTS - II

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Articles

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