NGC 7009: Testing the Wind-Wind Interaction Formation of Planetary Nebulae

It is commonly accepted that planetary nebulae (PNe) are formed by interactions between the current fast wind and a previous slow wind from the central star. The shockheated fast wind in the central cavity should be a diffuse Xray source. ROSAT observations of PNe have detected diffuse emission in two nebulae, NGC\\,6543 and Abell 30, but in both cases the Xrays appear to be associated with jets and outflows. To date, diffuse Xray emission from shocked stellar winds in PNe has not been unambiguously detected. We request a 30 ks XMM EPIC pn observation of NGC\\,7009, which was detected but not resolved by the ROSAT PSPC. This observation and our complementary optical observations allow a comprehensive investigation of the windwind interaction model of PNe. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]