Time evolution of the fitting parameters. The top rows show the total flux of the Voigt function (I ₀), the HWHM of the Gaussian component (﹩\sigma \sqrt{{\rm{ln}}4}﹩), and the HWHM of the Lorentzian component (γ) in the Voigt–Gauss function, respectively. The bottom row only shows the height (a _n ), the centroid (m), and the HWHM (﹩s\sqrt{{\rm{ln}}2}﹩) in the Gaussian function for the last four spectra, where profile asymmetries are observed. In each panel, the error bars represent uncertainties calculated from the fitting errors.