Structure of the Solar Core: Effect of Asymmetry of Peak Profiles

Recent studies have established that peaks in solar oscillation power spectra are not Lorentzian in shape but have a distinct asymmetry. Fitting a symmetric Lorentzian profile to the peaks, therefore, produces a shift in frequency of the modes. Accurate determination of low-frequency modes is essential to infer the structure of the solar core by inversion of the mode frequencies. In this paper we investigate how the changes in frequencies of low-degree modes obtained by fitting symmetric and asymmetric peak profiles change the inferred properties of the solar core. We use data obtained by the Global Oscillations at Low Frequencies (GOLF) project on board the SOHO spacecraft. Two different solar models and inversion procedures are used to invert the data in order to determine the sound speed in the solar core. We find that for a given set of modes no significant difference in the inferred sound speed results from taking asymmetry into account when fitting the low-degree modes.