SF2A-2005 : Semaine de l'Astrophysique Française, eds. F. Casoli, T. Contini, J.-M. Hameury and L. Pagani, EdP-Sciences, Conference Series n/a, p. 7 (2005)
Astron. and Astroph., 412, pp. 555-565 (2003)
Context. The small-scale magnetism of the quiet Sun has been investigated by various means in recent decades. It is now well established that the quiet Sun contains in total more magnetic flux than active regions and represents an important reservoir of magnetic energy. But the nature and evolution of these fields remain largely unknown.Aims....
International audience
International audience
Context. The study of the continuum radiative transfer problem inside circumstellar envelopes is both a theoretical and numerical challenge, especially in the frequency-dependent and multi-dimensional case. While approximate methods are easier to handle numerically, they often fail to accurately describe the radiation field inside complex...
The Ba II resonance line at 455.4 nm is formed in the low solar chromosphere. It shows significant linear polarization outside active regions close to the solar limb. This so-called resonance polarization is sensitive to the Hanle effect of weak magnetic fields. We report on numerical simulations of the intensity and resonance polarization...
International audience
International audience
Third Franco-Chinese Meeting on solar physics, n/a, (2006)
Context. The study of the continuum radiative transfer problem inside circumstellar envelopes is both a theoretical and numerical challenge, especially in the frequency-dependent and multi-dimensional case. While approximate methods are easier to handle numerically, they often fail to accurately describe the radiation field inside complex...
International audience
Context. In order to constrain the models describing circumstellar environments, it is necessary to solve the radiative transfer equation in the presence of absorption and scattering, coupled with the equation for radiative equilibrium. However, solving this problem requires much CPU time, which makes the use of automatic minimisation...
Context. The contribution of quiet-Sun regions to the solar irradiance variability is currently unclear. Certain solar-cycle variations of the quiet-Sun's physical structure, such as the temperature gradient, might affect the irradiance. Accurate measurements of this quantity over the course of the activity cycle would improve our understanding...
EAS Publications Series, 14, pp. 95-100
In this work we explore the diagnostic properties of the Na I D resonance lines by calculating the response functions of their line profiles to temperature and velocity perturbations in the atmosphere. We propose a method to transform spectral line intensity fluctuations measured at several wavelengths into temperature and velocity disturbances...
EAS Publications Series, 25, pp. 81-84
SF2A-2003 : Semaine de l'Astrophysique Française, eds. F. Combes, D. Barret, T. Contini and L. Pagani, EdP-Sciences, Conference Series n/a, p. 111 (2003)
EAS Publications Series, 14, pp. 95-100
Journées SF2A 2007, Scientific highlights 2007, eds. J. Bouvier, A. Chalabaev and C. Charbonnel, SF2A n/a, p. 601 (2007)
International audience
EAS Publications Series, eds. M. Giard, F. Casoli and F. Paletou, 14, pp. 95-100 (2005)
Abstract We present a new method to measure the rotational height gradient in the solar photosphere. The method is inspired from differential interferometric techniques, we applied it to spectroscopic observations in the FeI 630.15 nm obtained at the solar telescope THEMIS which is equipped with an efficient adaptive optics system. The...