X-ray variability in the quiescent state of Cen X-4
arXiv:astro-ph/9701234
Abstract
We report on a ROSAT-HRI observation of the soft X-ray transient Cen X-4 during quiescence. We discover a variation in the flux by a factor of 3 in less than four days. This relatively fast variation, the first observed from a quiescent soft X-ray transient, rules out some of the emission mechanisms that have been proposed for the quiescent flux. Accretion either onto the neutron star surface or onto the magnetospheric boundary is clearly favored.
2 pages and 1 figure, latex (A&A macro); accepted for publication in A&A