Diagnostics of the physical conditions in the powerful flare on October 28.2003

Аннотация

To study physical conditions in the solar flare we chose temperature sensitive lines of neutral iron with Lande-factor being equal to zero λ5434.534A, λ5123.73A. Usually such lines do not allow one to reproduce magnetic fields. Upper levels of FeI are connected with strong UV-lines which are thick in the photosphere and temperature minimum region and the lines support the level excitation nearly thermal. So non-LTE parameters of the lower and upper levels for the lines considered here are approximately equal that leads to S ≈ B; the latter condition provides the high sensitivity of lines to the temperature stratification.