Stellar Motion around Spiral Arms: Gaia Mock Data

TL;DR

This study uses Gaia mock data to differentiate between two models of spiral arm formation by analyzing stellar motions, demonstrating Gaia's capability to distinguish these scenarios.

Contribution

The paper introduces a method to compare stellar motions around spiral arms in different formation scenarios using Gaia mock data, highlighting Gaia's potential for such analyses.

Findings

Clear velocity differences between the two spiral arm models.

Gaia data volume and accuracy are sufficient for scenario distinction.

Method demonstrates potential for understanding spiral arm dynamics.

Abstract

We compare the stellar motion around a spiral arm created in two different scenarios, transient/co-rotating spiral arms and density-wave-like spiral arms. We generate Gaia mock data from snapshots of the simulations following these two scenarios using our stellar population code, SNAPDRAGONS, which takes into account dust extinction and the expected Gaia errors. We compare the observed rotation velocity around a spiral arm similar in position to the Perseus arm, and find that there is a clear difference in the velocity features around the spiral arm between the co-rotating spiral arm and the density-wave-like spiral arm. Our result demonstrates that the volume and accuracy of the Gaia data are sufficient to clearly distinguish these two scenarios of the spiral arms.