Bibcode
DOI
Koesterke, L.; Allende Prieto, C.; Lambert, D. L.
Referencia bibliográfica
The Astrophysical Journal, Volume 680, Issue 1, pp. 764-773.
Fecha de publicación:
6
2008
Revista
Número de citas
99
Número de citas referidas
86
Descripción
We examine closely the solar center-to-limb variation of continua and
lines and compare observations with predictions from both a
three-dimensional (3D) hydrodynamic simulation of the solar surface
(provided by M. Asplund and collaborators) and one-dimensional (1D)
model atmospheres. Intensities from the 3D time series are derived by
means of the new synthesis code ASSɛT, which overcomes
limitations of previously available codes by including a consistent
treatment of scattering and allowing for arbitrarily complex line and
continuum opacities. In the continuum, we find very similar
discrepancies between synthesis and observation for both types of model
atmospheres. This is in contrast to previous studies that used a
``horizontal'' and time-averaged representation of the 3D model and
found a significantly larger disagreement with observations. The
presence of temperature and velocity fields in the 3D simulation
provides a significant advantage when it comes to reproducing solar
spectral line shapes. Nonetheless, a comparison of observed and
synthetic equivalent widths reveals that the 3D model also predicts more
uniform abundances as a function of position angle on the disk. We
conclude that the 3D simulation provides not only a more realistic
description of the gas dynamics, but despite its simplified treatment of
the radiation transport, it also predicts reasonably well the observed
center-to-limb variation, which is indicative of a thermal structure
free from significant systematic errors.