Physical Structure of Planetary Nebulae. II. NGC 7662

Physical Structure of Planetary Nebulae . Ii . Ngc 7662

We present a study of the structure and kinematics of the triple-shell planetary nebula NGC7662 based on long-slit echelle spectroscopic observations and HST archival narrow-band images. The structure of NGC 7662 main nebula consists of a central cavity surrounded by two concentric shells. The bright inner shell has a non-negligible thickness and the highest density in the nebula. The outer she...

Physical Structure of Planetary Nebulae. Iii. the Large and Evolved Ngc 1360

NGC1360 is a large planetary nebula (PN) without an obvious shell morphology. We have analyzed Hα images and high-dispersion echelle spectra of NGC1360 in order to construct spatio-kinematic models and to determine its density distribution. The best-fit model indicates that NGC 1360 is a prolate ellipsoidal shell whose major axis is twice as long as its minor axis and is tilted by 60 with respe...

Abundances in planetary nebulae: NGC 2792

The mid-infrared spectrum of the rather circular planetary nebula NGC 2792 taken with the Spitzer Space Telescope is presented. This spectrum is combined with the ultraviolet IUE spectrum and with the spectrum in the visual wavelength region to obtain a complete, extinction corrected, spectrum. The chemical composition of the nebula is then calculated in two ways. First by directly calculating ...

Planetary nebulae as probes of dark matter in NGC 3384

Spectra of planetary nebulae in NGC 5128 ( Centaurus - A )

Low dispersion spectra have been obtained of five planetary nebulae in the elliptical galaxy NGC 5128 (Centaurus-A) from the catalogue of Hui et al. (1993b). The planetary nebulae (PN) cover a range of galactocentric radius from 7.9 to 17.7 (8 to 18Kpc). The spectra display typical emission lines of H I, He I, He II, [O III], [N II] and [S II] and appear very similar to high excitation planetar...