An X-ray study of AM Herculis. I. Discovery of a new mode of soft X-ray emission.
Stella, L.; Heise, J.; King, A. R.; Watson, M.; Brinkman, A. C.; Gronenschild, E.; Kieboom, K.
Netherlands, United Kingdom
Abstract
The discovery of a new mode of soft X-ray emission of the magnetic cataclysmic variable AM Her is reported. AM Her has been observed in June, August and September 1983 with EXOSAT in both hard (1-30 keV) and soft (40-120 A) X-rays. Hard X-rays were seen to be partially eclipsed and periodic with the white dwarf rotation period. The eclipse phases are consistent with previous X-ray observations. Soft-X-rays were seen in sharply separate high and low intensity levels, also periodic with the white dwarf rotation period. The soft X-ray high levels, however, coincide with the hard X-ray eclipses. In contrast to previous X-ray observations. These light curves are discussed in terms of emission from two magnetic poles of the white dwarf.