Spectroscopic investigations of planetary nebulae

Abstract

The morphologies of three selected asymmetrical planetary nebulae (PNe), namely NGC 4361, NGC 1514 and NGC 246, were studied using spatio-kinematic observations made with an Imaging Fabry-Perot Spectrometer. From the 3D spatio-kinematic models, plaussible nebular formation scenarios were proposed for NGC 4361 and NGC 1514 based on the interacting binary progenitor model. A few parameters regarding the binary, viz. the progenitor's mass and the binary separation, were suggested from this study. The elemental concentration of N and He in the nebulae were used to get some information regarding their progenitors. It is suggested from our study that the binary progenitor hypothesis gives more consistent / explanation of the observed structures of these PNe than the single star hypothesis. The physical condition of a PNe interacting with the ambient interstellar medium has been investigated in NGC 246. Its distorted morphology is attributed to its interaction with the Interstellar Medium (ISM).