A Detailed Morpho-Kinematic Model of the Eskimo, NGC 2392. A Unifying View with the Cat's Eye and Saturn Planetary Nebulae

TL;DR

This paper presents a detailed 3D morpho-kinematic model of the Eskimo nebula, revealing its structure and relation to similar planetary nebulae, using high-resolution spectroscopic data and HST imaging.

Contribution

It introduces a comprehensive spatially resolved spectroscopic mapping and a 3D model that unifies the Eskimo nebula with Saturn and Cat's Eye nebulae, considering orientation effects.

Findings

Eskimo nebula is a rotated analog of Saturn and Cat's Eye nebulae.

The model applies broadly to elliptical planetary nebulae with ansae or FLIERS.

The study suggests a common evolutionary sequence for these nebulae.

Abstract

The 3-D and kinematic structure of the Eskimo nebula, NGC 2392, has been notoriously difficult to interpret in detail given its complex morphology, multiple kinematic components and its nearly pole-on orientation along the line of sight. We present a comprehensive, spatially resolved, high resolution, long-slit spectroscopic mapping of the Eskimo planetary nebula. The data consist of 21 spatially resolved, long-slit echelle spectra tightly spaced over the Eskimo and along its bipolar jets. This data set allows us to construct a velocity-resolved [NII] channel map of the nebula with a resolution of 10 km/s that disentangles the different kinematic components of the nebula. The spectroscopic information is combined with HST images to construct a detailed three dimensional morpho-kinematic model of the Eskimo using the code SHAPE. With this model we demonstrate that the Eskimo is a close analog to the Saturn and the Cat's Eye nebulae, but rotated 90 degrees to the line of sight. Furthermore, we show that the main characteristics of our model apply to the general properties of the group of elliptical planetary nebulae with ansae or FLIERS, once the orientation is considered. We conclude that these kind of nebulae belongs to a class with a complex common evolutionary sequence of events.