Constraints on the dark-matter density profile of Eridanus 2 in the microphysical parametrization, assuming SIDM, found using CJAM and MultiNest. Units are omitted for clarity. The parameters are the characteristic dark-matter density (ρ₀) in M_⊙ kpc⁻³, the scale radius (r_s) in kpc, the effective self-interaction coefficient (fΓ) in cm³ s⁻¹ eV⁻¹ c², and the systemic velocity (v₀) in km s⁻¹. The contours correspond to 0.5σ, 1.0σ, 1.5σ, and 2.0σ confidence levels, where σ is the standard deviation of a two-dimensional normal distribution. The vertical dashed lines in the one-dimensional histograms indicate the median and the 68% confidence interval (without arrows) or the 68% and 95% confidence limits (upper and lower arrows, respectively).