Posterior densities for the minimum magnetic field strength for four values of the period under the original M₁ (solid) and the extended M₂ (dashed) pendulum models. The top panel displays results obtained with uniform priors, 𝒰(B [G]; 1, 100) and 𝒰(n [cm⁻³]; 10⁹, 10¹¹). The bottom panel shows the results obtained with 𝒰(B [G]; 1, 100) and a Gaussian prior on particle density, 𝒢(n [cm⁻³]; μ_n, σ_n), with μ_n = 10¹⁰ cm⁻³ and σ_n = 0.2μ_n. The numerical summaries of the posteriors are given in Table 1. A value of σ_P = 10 min and a 2D grid with N_n = N_B = 800 points were considered.