Fredagskollokvium: Robertus Erdelyi: Solar Magneto-Seismology: Are we close to solve one of the great problems of modern astrophysics?

Robertus Erdelyi, Head of Solar Physics and Space Plasma Research Centre in the Applied Mathematics Department at the University of Sheffield (UK).

The latest satellite and ground-based observations have provided a wealth of evidence of waves and oscillations present in the solar atmosphere. Our understanding of the structure and dynamics of the solar atmosphere has been considerably changed in light of the high spatial and time resolution observations (e.g. DST/ROSA, IBIS, CoMP, STT/CRISP; SOHO, TRACE, STEREO, Hinode, SDO, etc.) allowing us to perform sub-resolution magneto-seismology of MHD waveguides. First I will outline the basic recent developments in MHD wave theory focussing on linear waves.

Next,  I will concentrate on the role of Alfven waves,  and will discuss the latest status of the sometimes controversial observations of these particular,  and fundamentally important waves. Our theoretical interpretations of the detected Alfven wave and oscillatory phenomena within the framework of MHD will be shown. The photospheric origin and generation mechanism of these (and other) peculiar waves is addressed numerically. We will show how MHD (slow, fast and Alfven) waves penetrate into the chromosphere,  transition region or even into the corona. The coupling role of the magnetic field for MHD waves and oscillations between the solar interior and atmosphere will be addressed briefly. Finally,  we conclude how solar magneto-seismology evolved with MHD waves and how the new observational data on waves can be used for a more accurate solar and stellar atmospheric diagnostics,  including such important aspects as e.g. determining (i) the extent of the force free (or not!) nature of the solar and stellar atmosphere, (ii) the geometry,  (iii) fine structure,  and (iv) even the heating mechanism(s) of solar and stellar coronal plasmas.
 

Publisert 5. okt. 2011 15:37 - Sist endret 17. nov. 2011 20:33