The Origin of Soft X‐Rays in DQ Herculis

DQ Herculis (Nova Herculis 1934) is a deeply eclipsing cataclysmic variablecontaining a magnetic white dwarf primary. The accretion disk is thought toblock our line of sight to the white dwarf at all orbital phases due to itsextreme inclination angle. Nevertheless, soft X-rays were detected from DQ Herwith ROSAT PSPC. To probe the origin of these soft X-rays, we have performedChandra ACIS observations. We confirm that DQ Her is an X-ray source. The bulkof the X-rays are from a point-like source and exhibit a shallow partialeclipse. We interpret this as due to scattering of the unseen central X-raysource, probably in an accretion disk wind. At the same time, we observe whatappear to be weak extended X-ray features around DQ Her, which we interpret asan X-ray emitting knot in the nova shell.Comment: 18 pages including 4 figures, accepted for publication in Astrphyisical Journa