SNR-PWN system evolving in an interstellar medium with a density of ρ_ism = 10^-24 gcm^-3, with a higher density region, ρ_ism = 10^-23 gcm^-3 located at x = 5 pc. The results correspond to the M_ej = 3   M_⊙, τ = 3000 yr, and L₀ = 10³⁹ erg s^-1 scenario. The top halves of the panels show the density, and the bottom halves the magnetic field. The different panels represent snapshots of the evolution at various times. The time shown in the top-left corner of the panels correspond to the time elapsed after the initial explosion.