On the Shape of H and K Ca II Line Profiles in Sunspot Umbral Spectra

Emission cores of the H and K Caii lines observed in sunspot umbral spectra are mainly single-peaked, while semi-empirical umbral models predict their double-peak character. It is verified whether a single-peaked profile can be the result of the smearing of an originally double-peaked profile by macroturbulence. The integral convolution equation is solved for measured H and K profiles, and it is shown that, also after the deconvolution, they remain single-peaked even at an r.m.s. value of the macroturbulence velocity equal to 5 km s-1.