The wave-like disk oscillations of mono-age stellar populations in the Solar neighbourhood from Gaia DR3

TL;DR

This study uses Gaia DR3 data to analyze wave-like oscillations in the vertical structure of mono-age stellar populations in the Solar neighborhood, revealing consistent asymmetries across ages and larger velocity dispersions in older stars.

Contribution

It provides new evidence that vertical oscillations are uniform across different stellar ages, suggesting a common external influence affecting the Milky Way disk.

Findings

North-south asymmetries are consistent across all age groups.

Perturbations are likely ongoing or recent.

Older stars show larger vertical velocity dispersions.

Abstract

The North-South asymmetry in the number density and bulk velocity of stars in the solar neighborhood provides valuable insights into the formation and evolution of the Milky Way disk. Our objective is to investigate the wave-like disk oscillations of mono-age stellar populations in the Solar neighbourhood using data from Gaia Data Release 3. We have selected a comprehensive sample of main sequence turn off stars. The ages of these stars can be accurately determined using isochrone fitting methods. Our findings indicate that the north-south density and mean vertical velocity asymmetries remain consistent across all age groups.The uniformity of perturbations across all subsamples suggests that all populations are responding to the same external influence, which likely affects them irrespective of their age. Moreover, the fact that these perturbations appear consistently implies they could be either ongoing or recent. Regarding vertical velocity dispersions, we observe that older stars exhibit larger dispersions.