The X-ray Emission of Late-type Companions to Planetary Nebula Nuclei

Rapid rotation generates strong magnetic activity in latetype stars via adynamo. Latetype companions to the nuclei of planetary nebulae (PNe) areexpected to be rapid rotators due to accretion from the slow heavy wind of thenucleus while it was an AGB star, and hence strong Xray emitters. Yet,XMMNewton found two of three such stars to have Xray activity levels an orderof magnitude lower than those of other fast rotators. This impacts on ourunderstanding of unresolved Xray sources in PNe and may give clues as to thevital ingredients for an efficient dynamo. We aim to measure the Xray emissionlevel of the archetype, Abell 35, and the two brightest d. symbiotics, young PNecontaining latetype rapid rotators, to test the ubiquity of this low activity. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]