X-Ray Eclipse Mapping of AR Lacertae
Parmar, A. N.; White, N. E.; Culhane, J. L.; Horne, K.; Shafer, R. A.
Netherlands, United States, United Kingdom
Abstract
Exosat data of the binary cycle of the eclipsing RS CVn system AR Lac are studied. The data reveal that at energies of less than 1 ke V a factor of 2 intensity modulation is detected and at energies greater than 1 ke V no orbital modulation is observed. The chi-squared and maximum entropy methods are used to model low-energy modulation. The relation between the low-temperature component and height is examined. It is observed that 50 pct of the X-ray flux comes from a surface area covering up to 16 pct of the K star and 25 pct of the G star and that peak coronal pressure is about 100 dyne/sq cm.