Towards an explanation for the 30 Dor (LMC) Honeycomb nebula - the impact of recent observations and spectral analysis

TL;DR

This paper investigates the unique Honeycomb nebula in 30 Doradus, analyzing spectral data and modeling to explore its origin, suggesting it may be part of a larger shell structure and considering a supernova or microquasar origin.

Contribution

It provides a new spectral and spatiokinematic analysis of the Honeycomb nebula, proposing a novel interpretation of its structure and origin involving a giant shell and secondary supernova or microquasar activity.

Findings

The nebula's appearance is likely due to viewing angle effects.

It may be part of a larger, previously undetected giant shell.

A secondary supernova or microquasar activity could explain its features.

Abstract

The unique Honeycomb nebula, most likely a peculiar supernova remnant, lies in 30 Doradus in the Large Magellanic Cloud. Due to its proximity to SN1987A, it has been serendipitously and intentionally observed at many wavelengths. Here, an optical spectral analysis of forbidden line ratios is performed in order to compare the Honeycomb high-speed gas with supernova remnants in the Galaxy and the LMC, with galactic Wolf-Rayet nebulae and with the optical line emission from the interaction zone of the SS433 microquasar and W50 supernova remnant system. An empirical spatiokinematic model of the images and spectra for the Honeycomb reveals that its striking appearance is most likely due to a fortuitous viewing angle. The Honeycomb nebula is more extended in soft X-ray emission and could in fact be a small part of the edge of a giant LMC shell revealed for the first time in this short wavelength domain. It is also suggested that a previously unnoticed region of optical emission may in fact be an extension of the Honeycomb around the edge of this giant shell. A secondary supernova explosion in the edge of a giant shell is considered for the creation of the Honeycomb nebula. A microquasar origin of the Honeycomb nebula as opposed to a simple supernova origin is also evaluated.