Testing MURaM and MPS-ATLAS against the quiet solar spectrum

Abstract

Three-dimensional (3D) radiative magnetohydrodynamics (MHD) simulations are the only way to model stellar atmospheres without any ad hoc parameterisations. Several 3D radiative MHD codes have achieved good quantitative agreement with observables for our Sun. We aim to validate the most up-to-date version of the MURaM code against well established quiet Sun measurements, in particular spatially averaged measurements that are relevant for stellar studies. This validation extends the number of solar observables that MURaM can reproduce with high precision. It is also an essential condition for using MURaM to accurately calculate spectra of other cool stars. We simulate the solar upper convection zone and photosphere harbouring a small-scale-dynamo. Using time series of 3D snapshots we calculate the spectral irradiance, limb darkening and selected spectral lines, which we compare to observations. The computed observables agree well with the observations, in particular the limb darkening of the quiet Sun is reproduced remarkably well.

9 Page, 7 figures, accepted in A&A

References in corpus (12)

• A Substantial Amount of Hidden Magnetic Energy in the Quiet Sun
• Numerical simulations of quiet Sun magnetism: On the contribution from a small-scale dynamo
• A solar surface dynamo
• The Stagger-grid: A grid of 3D stellar atmosphere models - IV. Limb darkening coefficients
• Strong horizontal photospheric magnetic field in a surface dynamo simulation
• Solar Irradiance Variability is Caused by the Magnetic Activity on the Solar Surface
• MPS-ATLAS: A fast all-in-one code for synthesising stellar spectra
• Spectral variability of photospheric radiation due to faculae I: The Sun and Sun-like stars
• Can 1D radiative equilibrium models of faculae be used for calculating contamination of transmission spectra?
• Effects of continuum fudging on non-LTE synthesis of stellar spectra. I. Effects on estimates of UV continua and Solar Spectral Irradiance variability
• Small-scale dynamo in cool main sequence stars. II. The effect of metallicity
• Opacity for realistic 3D MHD simulations of cool stellar atmospheres

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• 3D Radiative MHD Simulations of Starspots II: Large-scale Structure
• Simulations of facular magnetic fields on cool stars I: Main sequence stars with solar metallicity
• A Panchromatic JWST Spectrum of a Giant Starspot on the Fully Convective M-dwarf TOI-3884