We report results from analysis of the X-ray observations of AE Aqr , made with Ginga in June 1988 and with ASCA in October 1995 .
Pulsations are detected clearly with a sinusoidal pulse profile with periods of 33.076 \pm 0.001 s ( Ginga ) and 33.077 \pm 0.003 s ( ASCA ) .
The pulse amplitude is relatively small and the modulated flux remains nearly constant despite a factor of 3 change in the average flux during the flare .
We reproduce the time-averaged spectrum in the 0.4 – 10 keV energy band by a thermal emission model with a combination of two different temperatures : kT _ { 1 } = 0.68 ^ { +0.01 } _ { -0.02 } keV and kT _ { 2 } = 2.9 ^ { +0.3 } _ { -0.2 } keV .
There is no significant difference between the quiescent and flare energy spectra , although a hint of spectral hardening is recognized during the flare .
We interpret these observational results with a model in which AE Aqr is in a propeller stage .
Based on this propeller scenario , we suggest that the X-ray emission is originated from magnetospheric radiation .