High-Resolution Spectroscopy of the Planetary Nebulae PM 1-242, PM 1-318 and PM 1-322

Abstract

We have recently confirmed the planetary nebula (PN) nature of PM 1-242, PM 1-318 and PM 1-322. 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. PM 1-242 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. PM 1-318 is a pole-on elliptical PN, instead of a circular one as suggested by direct images. PM 1-322 is spatially unresolved and its spectrum shows large differences between the forbidden lines and Ha profiles, with the latter showing a double-peaked profile and relatively extended wings (FWZI similar to 325 km s(-1)). These properties are found in other PNe that are suspected to host a symbiotic central star.