On the modifications of oscillator strengths and damping constants of Fe I spectral lines from 500 nm to 510 nm

Abstract

We modified oscillator strengths and enhancement factors of van der Waals damping constants for 84 moderately strong and weak neutral iron spectral lines between 500 nm and 510 nm, by fitting the solar synthetic spectrum to the observed one. We have found significant difference between the oscillator strengths and damping constants taken from an extensive spectral line list, frequently used for spectral synthesis, and their modified values. Our findings include: (1) the mean value of the distribution of the difference between our and listed oscillator strengths is -0.31dex and its width is 0.42 dex, (2) a decrease of this difference with increasing equivalent width of spectral lines, (3) unusually high values of the obtained enhancement factors in comparison with the results of other authors, (4) a decrease of enhancement factor with increasing excitation potential for lines with equivalent width greater than 7.5 pm, (5) a decrease of enhancement factors with increasing equivalent width and (6) a decrease of enhancement factors with increasing oscillator strengths.