Letter to the Editor
An eclipse in the X-ray flux from the dwarf nova Z Cha
André van Teeseling
Received 5 December 1996 / Accepted 10 January 1997
Observations obtained with the ROSAT HRI show that the X-rays from the dwarf nova Z Cha in quiescence are eclipsed together with the white dwarf. This confirms the idea that the X-rays are emitted by a narrow boundary layer between the accretion disk and the white dwarf, although a point-like X-ray source near the white-dwarf surface cannot be excluded. The observations further show that during quiescence the mass accretion onto the white dwarf continues, even more than three months after outburst, at a level of yr-1.
Key words: accretion, accretion disks - stars: individual: Z Cha - cataclysmic variables - X-rays: stars
© European Southern Observatory (ESO) 1997
Online publication: July 3, 1998