Constraining the shape of the accretion disk in Her X-1: II. EUV observations
نویسنده
چکیده
The bright X-ray binary pulsar Hercules X-1 has a 35-day cycle in hard x-ray intensity: ”Main High state – low state – Short High state – low state”. This is caused by a tilted-twisted precessing accretion disk. What is less well known is that during low states the soft x-rays and extreme ultraviolet radiation are modulated at the orbital period . This radiation is mainly due to reflection off of the companion star HZ Her. Here a model of the accretion disk and the companion star is constructed to model the observations of Her X-1 by the Extreme Ultraviolet Explorer (EUVE). It is found that there is also an EUV emission component from the accretion disk. The accretion disk shape is constrained from the shadowing effect on HZ Her.
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