Modeling the Local Warm/Hot Bubble

TL;DR

This paper reviews recent advances in modeling the Local Bubble, highlighting the role of a moving group in its formation, and demonstrates that high-resolution simulations can reproduce observed properties and evolution of this local interstellar structure.

Contribution

It provides new insights into the origin of the Local Bubble and demonstrates the effectiveness of 3D simulations in reproducing its properties and evolution.

Findings

Simulations match the observed extension and OVI absorption of the LB.

The LB likely formed due to a moving group crossing the region.

The LB experienced blow-out into the Milky Way halo about 5 Myr ago.

Abstract

In this paper we review the modeling of the Local Bubble (LB) with special emphasis on the progress we have made since the last major conference "The Local Bubble and Beyond (I)" held in Garching in 1997. Since then new insight was gained into the possible origin of the LB, with a moving group crossing its volume during the last 10 - 15 Myr being most likely responsible for creating a local cavity filled with hot recombining gas. Numerical high resolution 3D simulations of a supernova driven inhomogeneous interstellar medium show that we can reproduce both the extension of the LB and the OVI column density in absorption measured with FUSE for a LB age of 13.5 - 14.5 Myr. We further demonstrate that the LB evolves like an ordinary superbubble expanding into a density stratified medium by comparing analytical 2D Kompaneets solutions to NaI contours, representing the extension of the local cavity. These results suggest that LB blow-out into the Milky Way halo has occurred roughly 5 Myr ago.