Analysis of asymmetric p-mode profiles in GOLF data

We show here evidence for the necessity of an asym- metric form in modelling the profile of an acoustic mode in the power spectral density. The analysis was performed on a 805- day series of GOLF data ('=0 to 3). The assumptions used for the fits are discussed and their consequences quantified, in par- ticular for the optimum choice of the fitting spectral window. Values are given for the bias on the mode parameters (frequency, width, splitting) when using a Lorentzian fit. The bias depends on the degree ' and on the frequency, and when taken into ac- count leads to variations in the mode parameters with degree more consistent with theoretical expectations.