Skew-symmetric solar p modes in low-l BiSON data

The p-mode oscillations of the Sun are manifestations of resonantly trapped acoustic waves propagating within its interior. The effective size of the resulting resonant cavity changes with the properties of the modes - the in teraction of this phenomenon with a highly localized excitation source in t he upper layers of the convection zone gives rise to skew-symmetric resonan t profiles whose degree of asymmetry changes with frequency. Here, we have fitted low-angular-degree (low-l) resonant p-mode peaks - in a power spectr um generated from 32 months of BiSON Doppler velocity observations of the v isible solar disc - to a skew-symmetric formalism to account for this effec t. We present the fitted frequencies, fine-structure spacings [d(0)(n) and d(1)(n)] and mode-skewness estimates; and discuss the quantitative impact o f fitting a skew, rather than symmetric, limit model. We also consider the reliability of the extracted parameters through the application of a useful statistical test, and extensive Monte Carlo fits to artificial data.