The Astrophysical Journal · 1990 · 57 citations · 0 references
Natural SciencesAstronomyPhysicsAstrophysicsStellar AstronomyX-ray AstronomySolar X-ray AstronomySpace-based Gamma-ray ObservatoriesStellar StructureX-ray BinariesX-ray Data AnalysisBinary Orbital ModulationEclipse MappingEclipsing Binary SpectraEclipsing Binary StarsEclipsing X-ray BinariesIntensity ModulationMaximum Entropy EstimationStellar X-ray Radiation
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.