Numerical simulations of solar surface convection have predicted the existence of supersonic horizontal flows in the photospheric granulation. Recently, the detection of such flows in data from the Hinode satellite was reported. We study supersonic …
Phase-diversity techniques provide a novel observational method for overcoming the effects of turbulence and instrument-induced aberrations in ground-based astronomy. Two implementations of phase-diversity techniques that differ with regard to noise …
We present a method to obtain diffraction limited spectrograms of extended sources from a series of ground-based slit- spectrograms. The method is a combination of speckle deconvolution (Keller & von der Luehe 1992) and a rapid spectrograph …
A set of narrow-band filtergrams of the solar photosphere recorded in three widely separated true continuum windows and in Mg I b1 with a spatial resolution of about 0.5 arcsec is analyzed. The influence of small-scale magnetic fields on the …