ℓ Car IR excess fitting result of ionized gas shell following the method described in Paper I. Yellow region is the error on the magnitude obtained using the covariance matrix of the fitting result. We find a thin shell of ionized gas with radius R_shell = 1.13 ± 0.02 R_⋆; temperature T_shell = 3791 ± 85 K; mass of ionized gas M = 9.10 × 10⁻⁸ ± 8.5 × 10⁻⁹ M_⊙, using an ad hoc offset of +0.03 mag on the data in order to match the IR excess found by VLTI/MATISSE and the one of SPIPS (see the text); and . The subplot shows the comparison between the flux contribution derived from the Gaussian CSE (dashed line), the IR excess from SPIPS (red point) and IR excess from a shell of ionized gas in the LM band (red line).