Publication Date:
2015-09-16
Description:
In this paper we present the results of optical high-resolution imaging and spectroscopy of the complex planetary nebula (PN) NGC 3242. Our study is based on the analysis of the narrow-band Hα 6563, [O iii ] 5007, [N ii ] 6584, and [S ii ] 6724 Å images, and high-resolution spectroscopy using spectral ranges centred on the Hα 6564, [N ii ] 6583, and [O iii ] 5007 Å. We detected and analysed morphological components beyond the multiple-shell structure of this PN, to investigate the small-scale morphological components aligned towards its major axis (such as knots and ansae, as well as the arc-like features) and its surroundings. Thus, we investigated the morpho-kinematical properties of NGC 3242, as well as their nature and formation. Our results regarding the elliptical double-shell structure and the distance to this nebula are in concordance with previous studies. Furthermore, we have used the software shape to construct a 3D model of NGC 3242, allowing us to successfully reproduce our observational data. We conclude that the prominent knots emitting in the [N ii ] line are fast, low-ionization emission regions related to high-velocity jets and the so-called ansae-like features rather resemble bubbles. The disruptions immersed in the halo, whose emission was detected in the [O iii ] high-excitation emission line, remarkably display high velocities and were formed likely in an earlier ejection event, in comparison to the innermost low-ionization structures and bubbles. Finally, according to our model, the kinematical ages of the structures in NGC 3242 range from 390 to 5400 yr.
Print ISSN:
0035-8711
Electronic ISSN:
1365-2966
Topics:
Physics
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