High Resolution Spectroscopy of the Planetary Nebulae PM1-242, PM1-318 and PM1-322

TL;DR

This study uses high-resolution spectroscopy to analyze the internal kinematics and physical structures of three planetary nebulae, revealing their true shapes and potential symbiotic star features.

Contribution

It provides detailed kinematic and structural analysis of three PNe, correcting previous shape assumptions and suggesting possible symbiotic central stars.

Findings

PM1-242 is a tilted ring, not elliptical.

PM1-318 is a pole-on elliptical PN.

PM1-322 shows spectral features indicative of symbiotic stars.

Abstract

We have recently confirmed the planetary nebula (PN)nature of PM1-242, PM1-318 and PM1-322. Here we present high-resolution long-slit spectra of these three PNe in order to analyze their internal kinematics and to investigate their physical structure. PM1-242 is a tilted ring and not an elliptical PN as suggested by direct images. The object is probably related to ring-like PNe and shows an unusual point-symmetric brightness distribution in the ring. PM1-318 is a pole-on elliptical PN, instead of a circular one as suggested by direct images. PM1-322 is spatially unresolved and its spectrum shows large differences between the forbidden lines and H$\alpha$ profiles, with the latter showing a double-peaked profile and relatively extended wings (FWZI $\sim$ 325 km\,s$^{-1}$). These properties are found in other PNe that are suspected to host a symbiotic central star.