First overtone and higher-order modes in the ringdown signal of GW231028

Analyze the ringdown signal of GW231028 using the F-statistic method, with the start time range set to [8, 20]M after the polarization peak, in 2M intervals (where M corresponds to 246.4 solar masses in time dimension). Files should be named in the format "{mode}_{start_t}_{duration}" – for instance, "222_10M_0-4s" indicates analysis of 220+221 modes starting 10M post-merger with 0.4s ringdown data. Posterior samples are stored in corresponding JSON files, where amplitude and phase parameters prefixed with "P_" denote posteriors under physical priors (refer to arXiv:2509.08657 for details); those without prefixes represent amplitude and phase values calculated at maximum likelihood based directly on θ. For example, the posterior name for the 221 mode amplitude under physical priors would be "P_amp221".