(left panel), natural logarithm of the mode linewidth (middle panel), and entropy (right panel) of the m-averaged spectrum as a function of the shift coefficient a ₁ obtained from 10 simulated l = 15 spectra. The vertical dashed lines represent the introduced value of a ₁ (400 nHz) in the simulations. The horizontal dotted-dashed line in the center panel represents the mode linewidth of the simulated spectra, 0.4 μHz.