Three-dimensional hydrodynamical simulations of red giant stars: semi-global models for the interpretation of interferometric observations

Abstract

Context. Theoretical predictions from models of red giant branch stars are a valuable tool for various applications in astrophysics ranging from galactic chemical evolution to studies of exoplanetary systems. Aims. We use the radiative transfer code OPTIM3D and realistic 3D radiative-hydrodynamical (RHD) surface convection simulations of red giants to explore the impact of granulation on interferometric observables. Methods. We compute intensity maps for the 3D simulation snapshots in two filters: in the optical at 5000 \pm 300 Å and in the K band 2.14 $\pm$ 0.26 μm FLUOR filter, corresponding to the wavelength-range of instruments mounted on the CHARA interferometer. From the intensity maps, we construct images of the stellar disks, accounting for center-to-limb variations. We then derive interferometric visibility amplitudes and phases. We study their behavior with position angle and wavelength. Results. We provide average limb-darkening coefficients for different metallicities and wavelength-ranges. We detail the prospects for the detection and characterization of granulation and center-to-limb variations of red giant stars with today's interferometers. We find that the effect of convective-related surface structures depends on metallicity and surface gravity. We provided theoretical closure phases that should be incorporated into the analysis of red giant planet companion closure phase signals. We estimate 3D-1D corrections to stellar radii determination: 3D models are ~ 3.5% smaller to ~ 1% larger in the optical with respect to 1D, and roughly 0.5 to 1.5% smaller in the infrared. Even if these corrections are small, they are important to properly set the zero point of effective temperature scale derived by interferometry and to strengthen the confidence of existing red giant catalogues of calibrating stars for interferometry.

Accepted for publication on Astronomy & Astrophysics, 14 pages, 13 figures

References in corpus (10)

• A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
• Precise radial velocities of giant stars. III. Spectroscopic stellar parameters
• 3D Hydrodynamical Simulations of Surface Convection in Red Giant Stars. Impact on spectral line formation and abundance analysis
• Accurate fundamental parameters for Lower Main Sequence Stars
• Retired A Stars and Their Companions II: Jovian planets orbiting kappa Coronae Borealis and HD167042
• Tests of stellar model atmospheres by optical interferometry: VLTI/VINCI limb-darkening measurements of the M4 giant psi phe
• Discovery of a planet around the K giant star 4 UMa
• The 2010 Interferometric Imaging Beauty Contest
• Closure Phase Signatures of Planet Transit Events
• Prospects for near-infrared characterisation of hot Jupiters with VSI

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