3D hydrodynamical model atmospheres: a tool to correct radial velocities and parallaxes for Gaia

TL;DR

This paper discusses the use of 3D hydrodynamical models of stellar atmospheres to improve the accuracy of radial velocity and parallax measurements in Gaia by accounting for convection-related surface effects.

Contribution

It introduces 3D time-dependent hydrodynamical simulations as a tool to correct Gaia measurements for convection-induced biases.

Findings

3D models improve radial velocity accuracy

Enhanced parallax estimates with convection corrections

Better understanding of surface variability effects

Abstract

Convection plays an essential role in the emerging intensity for many stars that will be observed by Gaia. Convective-related surface structures affect the shape, shift, and asymmetry of absorption lines, the phocentric and photometric variability causing bias in Gaia measurements. Regarding the importance of Gaia mission and its goals, it is mandatory to have the best models of the observed stars. 3D time-dependent hydrodynamical simulations of surface convection are crucial to model the photosphere of late type stars in a very realistic way. These simulations are an important tool to correct the radial velocities and better estimates the parallaxes and photometric variability.