Observations, analysis and interpretation with non-LTE of chromospheric structures of the Sun

TL;DR

This thesis presents high-resolution observations and analysis of solar chromospheric structures like spicules and fibrils, using advanced spectropolarimetric and imaging techniques to understand their dynamics and properties with non-LTE modeling.

Contribution

It provides detailed observational data and analysis of chromospheric features using non-LTE methods, high-resolution imaging, and speckle reconstruction, advancing understanding of solar chromospheric dynamics.

Findings

Spicules can reach heights of 8 Mm above the limb.

Spicules outside the limb continue as dark fibrils inside the disc.

Variation of off-limb emission profiles correlates with distance from the limb.

Abstract

This thesis is based on observations performed at the Vacuum Tower Telescope (Tenerife). We have used an infrared spectropolarimeter (TIP) and a Fabry-Perot spectrometer (G-FPI) from years 2004 to 2006. We have applied several imaging speckle reconstruction techniques, and compared them. We have studied chromospheric dynamics inside the solar disc and at the limb using H\alpha with very high spatial, spectral and temporal resolution. Keywords (see full abstract for details): fibrils, surge, MHD waves, speckle, blind deconvolution, Fabry-Perot, mini-flares, cloud model, spicules in Halpha, spicules continuing on the disc) Using He I 10830 we studied the offlimb spicular spectral I profiles with height over the limb. The analysis shows the variation of the off-limb emission profiles as a function of the distance to the visible solar limb. The intensity ratio of the multiplet (which is related to the optical thickness and coronal irradiation) is studied and compared with standard atmospheric models. We report observational properties from high-resolution filtergrams in the H$\alpha$ spectral line taken with the G-FPI. We find that spicules can reach heights of 8 Mm above the limb. We show that spicules outside the limb continue as dark fibrils inside the disc.