Detailed studies of IPHAS sources -- I. The disrupted late bipolar IPHASX J193718.6+202102

TL;DR

This paper provides a detailed analysis of the planetary nebula IPHASX J193718.6+202102, revealing its complex structure, kinematics, and chemical composition, and suggesting it is an evolved, disintegrating bipolar nebula.

Contribution

It offers the first detailed morpho-kinematic and photoionisation modeling of this nebula, uncovering its fragmented structure and evolutionary status.

Findings

The nebula has a fragmented torus and faint bipolar outflow.

The torus expands at 25 km/s and is breaking up.

Estimated age of the nebula is approximately 26,000 years.

Abstract

We present a detailed analysis of the new planetary nebula (PN) IPHASX J193718.6+202102 using deep imaging and intermediate- and high resolution spectroscopy that are interpreted through morpho-kinematic and photoionisation modelling. The physical structure of the nebula consists of a fragmented torus and an extremely faint orthogonal bipolar outflow, contrary to the pinched waist PN morphology suggested by its optical image. Our kinematic analysis indicates that the torus is expanding at 25$\pm$5 km s$^{-1}$ and is gradually breaking up. At an estimated distance of 7.1$_{-0.3}^{+0.8}$ kpc, the corresponding kinematic age of $\sim$26000 years is consistent with a faint and disintegrating PN. The intermediate-resolution spectra reveal an excited PN with chemical abundances typical of Type II PNe. Based on the latter we also estimate an initial mass for the progenitor in the range 2--3 M$_{\odot}$ and a central star (CSPN) mass $M_\mathrm{CSPN}\sim$0.61 M$_{\odot}$. The Spitzer MIPS 24 $\mu$m emission that closely follows the fragmented torus could be attributed to the emission of [O IV] at 25.9 $\mu$m rather than to dust emission. All the results coherently point towards an evolved moderately massive bipolar Type II PN on the brink of dissolving into the interstellar medium.