On the difference of the formation depth of centre of weak Fraungofer lines and far wings of strong ones

The Voigt function H(a, v) influence on the absorption coefficient of the centre and of the wing of a Fraunhofer line of the photosphere is investigated. The absorption coefficient of the line centre is K(0) approximately N/Δlambdasub(D), and the one of the far wings is K(v) approximately Nγ. Here N is the concentration of absorbing atoms, Δlambdasub(D) is the Doppler width, γ is the damping-broadening constant, sharply increasing downward into the photosphere. Due to this, the effective depths of formation of far wings of strong lines are larger than those of weak lines, having the same atomic parameters