A Detailed Morpho-Kinematic Model of the Eskimo, NGC 2392: A Unifying View With the Cat's Eye and Saturn Planetary 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 −1 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 • 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.

Characterization of the planetary nebula Tc 1 based on VLT X-shooter observations

“…In (a) the ellipsoid is seen pole on; in (b) and (c) the ellipsoid is turned to the right by 50 and 90 degrees angles, respectively; (d) is the observer's view, i.e., the ellipsoid originally pole-on (a) is turned down by 6 degrees from the light of sight and clockwise 50 degrees. strongly resembles that of NGC 2392 (García-Díaz et al 2012), which also has similar asymmetries seen in [N ii]. The main difference between the two nebulae is that NGC 2392 shows a spherical rather than an elliptical morphology.…”

The imprints of the last jets in core collapse supernovae

“…The jets shaped the inner bright part to have a hollow cylindrical shape, that on projection reveals two arcs. For more PNe that show jets together with a hollowed central bright nebula see for example García-Díaz et al (2012), Clark et al (2013) and Clyne et al (2015). Had the jets of A 63 been a little fainter, we would not have detected them.…”

Variable Hard X-Ray Emission from the Central Star of the Eskimo Nebula

“…First, the outflow speed of 180 km s −1 is not able to shockheat material up to X-ray-emitting temperatures. Second, the spatial distributions of the diffuse X-ray emission and collimated outflows do not match; the collimated outflows extends further out from the inner shell (García-Díaz et al 2012), whereas the diffuse emission is well confined within the inner shell and it does not show any "hot spot" indicative of interactions between the collimated outflow and the nebular material (Ruiz et al 2013). According to recent hot bubble hydrodynamical simulations (Toalá & Arthur 2016), the stellar wind of the CSPN of NGC 2392 is only just capable of powering the diffuse X-ray emission, a situation that can be favored by the contribution of the stellar wind from the WD companion (Miszalski et al 2019).…”

“…Everything else in NGC 2392 is atypical. The expansion velocity of its inner shell, ∼120 km s −1 , is spectacularly large among elliptical shells of PNe Corresponding author: Martín A. Guerrero mar@iaa.es (Reay et al 1983;O'Dell & Ball 1985;O'Dell et al 1990;García-Díaz et al 2012). Its fast ∼180 km s −1 collimated outflow, the first ever detected among PNe (Gieseking et al 1985), can be traced down to its central star (CSPN), a situation uncommon among collimated outflows of PNe.…”