SOLARNET Conference: The Many Scales of the Magnetic Sun

Many solar spectral lines have poorly determined atomic parameters, such as the transition probability or the central wavelength, especially in the near-ultraviolet (NUV) range. We present a novel approach to exploit high-angular-resolution spectropolarimetric observations of the Sun to obtain precise atomic parameters of spectral lines, required for the proper analysis of solar and stellar observations. The inversion-based approach requires that unique (global) values of atomic parameters must represent very well spectral line profiles originating from very different solar atmospheres within an observed field of view. To test this so-called global method, we analyzed synthetic spectra computed from magneto-hydrodynamic models of the solar atmosphere and compared the results to the previously used methods. The method is general enough to be applied to the spectral lines from the NUV to the infrared wavelengths. The global method is able to retrieve reliable estimates of atomic parameters even for weak and blended spectral lines, thus extending the list of spectral lines with reliable atomic parameters used to analyze solar and stellar spectra.