Morpho-kinematics of the planetary nebula NGC 3242: an analysis beyond its multiple-shell structure

• Published in: Monthly notices of the Royal Astronomical Society 2015-11, Vol.453 (4), p.4175-4184
• Main Authors: Gómez-Muñoz, M. A., Blanco Cárdenas, M. W., Vázquez, R., Zavala, S., Guillén, P. F., Ayala, S.
• Format: Article
• Language: English
• Subjects: Astronomy; Bubbles; Computer programs; Emission; Imaging; Kinetics; Knots; Morphology; Nebulae; Planetary nebulae; Planets; Spectroscopy; Spectrum analysis; Symbols
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1093/mnras/stv1922

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 λ6563, [O iii] λ5007, [N ii] λ6584, and [S ii] λ6724 Å images, and high-resolution spectroscopy using spectral ranges centred on the Hα λ6564, [N ii] λ6583, and [O iii] λ5007 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.