Ionisation Structure of NGC 6543

Fuse Observations of Nebular O Vi Emission from Ngc 6543 ∗

NGC6543 is one of the few planetary nebulae (PNe) whose X-ray emission has been shown to be extended and originate from hot interior gas. Using FUSE observations we have now detected nebular O VI emission from NGC6543. Its central star, with an effective temperature of ∼50,000 K, is too cool to photoionize O V, so the O VI ions must have been produced by thermal collisions at the interface betw...

The central stars of the planetary nebulae NGC 7027 and NGC 6543 ?

Infrared spectra of NGC 7027 and NGC 6543 ranging from 2.4 to 45 m were obtained with the Short Wavelength Spectrometer on board the Infrared Space Observatory. A first analysis of these spectra, with the aid of photo-ionization models, is presented. We report the first detection of the [Arvi] 4.53 m and [Nevi] 7.65 m lines in the spectrum of NGC 7027. When compared with older observations it i...

Physical Conditions in Ngc 6543 from Iso and Hst Data and the Pitfalls of Temperature Maps

We determine the physical conditions in NGC 6543, obtaining two different estimates of the electron temperature (Te) and one estimate of the electron density (Ne). The electron temperature is computed by means of the [O iii] ratio λ 5007/λ 4363, and of the diagnostic diagram combining λ 5007 to the [O iii] infrared lines 52μ and 88μ. The continuum intensity measured on slit spectra is much high...

Physical conditions in the O + + zone from ISO 1 and HST data . NGC 6543 revisited

Ionisation Structure in Accretion Shocks with a Composite Cooling Function

We have investigated the ionisation structure of the post-shock regions of magnetic cataclysmic variables using an analytic density and temperature structure model in which effects due to bremsstrahlung and cyclotron cooling are considered. We find that in the majority of the shock-heated region where Hand He-like lines of the heavy elements are emitted, the collisional-ionisation and corona-co...