Panchromatic HST WFC3 Imaging Studies of Young, Rapidly Evolving Planetary Nebulae II NGC 7027 by Paula Moraga Baez et al. on Wednesday 30 November

The iconic planetary nebula (PN) NGC 7027 is bright, nearby (D ~ 1 kpc),

highly ionized, intricately structured, and well observed. This nebula is hence

an ideal case study for understanding PN shaping and evolution processes.

Accordingly, we have conducted a comprehensive imaging survey of NGC 7027

comprised of twelve HST Wide Field Camera 3 images in narrow-band and continuum

filters spanning the wavelength range 0.243--1.67 microns. The resulting

panchromatic image suite reveals the spatial distributions of emission lines

covering low-ionization species such as singly ionized Fe, N, and Si, through H

recombination lines, to more highly ionized O and Ne. These images, combined

with available X-ray and radio data, provide the most extensive view of the

structure of NGC 7027 obtained to date. Among other findings, we have traced

the ionization structure and dust extinction within the nebula in sub-arcsecond

detail; uncovered multipolar structures actively driven by collimated winds

that protrude through and beyond the PN's bright inner core; compared the

ionization patterns in the WFC3 images to X-ray and radio images of its

interior hot gas and to its molecular outflows; pinpointed the loci of thin,

shocked interfaces deep inside the nebula; and more precisely characterized the

central star. We use these results to describe the recent history of this young

and rapidly evolving PN in terms of a series of shaping events. This

evolutionary sequence involves both thermal and ram pressures, and is far more

complex than predicted by extant models of UV photoionization or winds from a

single central progenitor star, thereby highlighting the likely influence of an

unseen binary companion.

arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2210.01859v2