High Galactic latitude runaway stars as tracers of the spiral arms

TL;DR

This paper proposes a novel method using high Galactic latitude runaway stars to map the Galaxy's spiral arms and analyze their dynamics, overcoming observational challenges posed by our position within the Galactic plane.

Contribution

The paper introduces a new approach to trace spiral arms using runaway stars' birthplaces, with initial results and future prospects based on Gaia data.

Findings

Estimated pattern speed of spiral arms

Determined spiral arm phase angle

Assessed Gaia data's potential for this method

Abstract

A direct observation of the spiral structure of the Galaxy is hindered by our position in the middle of the Galactic plane. We propose a method based on the analysis of the birthplaces of high Galactic latitude runaway stars to map the spiral arms and determine their dynamics. As a proof of concept, the method is applied to a local sample of early-type stars and a sample of runaways stars to obtain estimates of the pattern speed and the spiral arm's phase angle. We also estimate the performance of this method once the data gathered by Gaia, in particular for runaway stars observed on the other side of the Galaxy, is available.