The general aim of this project is the investigation of astrophysical processes through the use of stateoftheart numerical codes on massively parallel computers. More specifically, the research in many astrophysical fields requires an understanding of gas dynamical, magnetic, radiative transfer and gravitational phenomena not accessible to purely theoretical analysis. In the framework of this project calculation aimed at understanding the multidimensional structure and evolution of magnetic fields in stellar atmospheres and interiors are carried out, including magnetohydrodynamical aspects, radiative transfer and spectral line polarization. Special emphasis is placed on the comparison of the theoretical/numerical results with observational data.
Members of the project
Highlights and results
- Small magnetic loops are observed to appear in the interior of individual granules in the quiet Sun. Using 3D numerical the mechanisms that produce this emergence is discovered. The results have been published in ApJ Letter 859, id. L26 and led by Prof Fernando Moreno-Insertis.
- In an international collaboration, almost 200 solar prominence oscillations events have been catalogued. This is the first statistically significant study of these phenomena done that also includes large-amplitude oscillations. This work has been led by Dr Manuel Luna and published in ApJ Supplement Series, 236, id. 35.
Magneto-acoustic waves in sunspots from observations and numerical simulations
We study the propagation of waves from the photosphere to the chromosphere of sunspots. From time series of cospatial Ca II H (including its line blends) intensity spectra and polarimetric spectra of Si I λ 1082.7 nm and He I λ 1083.0 nm we retrieve the line-of-sight velocity at several heights. The analysis of the phase difference andFelipe, T. et al.
Non-LTE Determination of the Silicon Abundance Using a Three-dimensional Hydrodynamical Model of the Solar Photosphere
Confrontations of spectroscopic observations with local thermodynamic equilibrium (LTE) spectral syntheses in a three-dimensional (3D) hydrodynamical model of the solar photosphere led to a downward revision of the photospheric and meteoritic silicon abundances. Here we derive the photospheric silicon abundance taking into account non-LTE (NLTE)Shchukina, N. et al.
Stellar Kinematics in Double-Barred Galaxies: The σ-Hollows
We present SAURON integral-field stellar velocity and velocity dispersion maps for four double-barred early-type galaxies: NGC 2859, NGC 3941, NGC 4725, and NGC 5850. The presence of the inner bar does not produce major changes in the line-of-sight velocity, but it appears to have an important effect in the stellar velocity dispersion maps: we findde Lorenzo-Cáceres, A. et al.