3-D Dynamics of Interactions between Stellar Winds and the Interstellar Medium as Seen by AKARI and Spitzer

TL;DR

This paper discusses a new technique to analyze the 3-D dynamics of stellar wind and interstellar medium interactions using far-infrared observations from AKARI and Spitzer, demonstrated on three stars.

Contribution

It introduces a novel method to determine the local ISM flow vector by fitting bow shock structures observed in infrared data.

Findings

Successful application to Betelgeuse, R Hydrae, and R Cassiopeiae

Provides insights into local ISM flow vectors

Enhances understanding of stellar wind-ISM interactions

Abstract

Recent far-infrared mapping of mass-losing stars by the AKARI Infrared Astronomy Satellite and Spitzer Space Telescope have suggested that far-infrared bow shock structures are probably ubiquitous around these mass-losing stars, especially when these stars have high proper motion. Higher spatial resolution data of such far-infrared bow shocks now allow detailed fitting to yield the orientation of the bow shock cone with respect to the heliocentric space motion vector of the central star, using the analytical solution for these bow shocks under the assumption of momentum conservation across a physically thin interface between the stellar winds and interstellar medium (ISM). This fitting analysis of the observed bow shock structure would enable determination of the ambient ISM flow vector, founding a new technique to probe the 3-D ISM dynamics that are local to these interacting systems. In this review, we will demonstrate this new technique for three particular cases, Betelgeuse, R Hydrae, and R Cassiopeiae.