Kompaneets Model Fitting of the Orion-Eridanus Superbubble II: Thinking Outside of Barnard's Loop

TL;DR

This paper uses Kompaneets models to analyze the expanded shape of the Orion-Eridanus superbubble, demonstrating that its morphology aligns with expansion into the Galactic disk's exponential atmosphere with realistic scale heights.

Contribution

It provides the first fit of the Orion-Eridanus superbubble using updated boundary data, showing consistency with standard Galactic disk parameters.

Findings

Superbubble shape fits models with 80 pc scale height.

Expansion primarily influenced by the Galactic disk's exponential atmosphere.

Model orientation explains the larger observed morphology.

Abstract

The Orion star-forming region is the nearest active high-mass star-forming region and has created a large superbubble, the Orion-Eridanus superbubble. Recent work by Ochsendorf et al. has extended the accepted boundary of the superbubble. We fit Kompaneets models of superbubbles expanding in exponential atmospheres to the new, larger shape of the Orion-Eridanus superbubble. We find that this larger morphology of the superbubble is consistent with the evolution of the superbubble being primarily controlled by expansion into the exponential Galactic disk ISM if the superbubble is oriented with the Eridanus side farther from the Sun than the Orion side. Unlike previous Kompaneets model fits that required abnormally small scale heights for the Galactic disk (<40 pc), we find morphologically consistent models with scale heights of 80 pc, similar to that expected for the Galactic disk.