Density ratio of old stars (>10 Gyr old) between sex156 models and the Sextans-type isolation model. Line colours and styles are the same as in Fig. 2. The age threshold selects only stars that were formed well before star formation was quenched in any simulation (see also Fig. 8). Even with such an old stellar population, the tidal effects are still visible, with all models having the central density lowered (although with some scatter) and increasing in density at higher radius. The magnitude of the change indicates that tidal forces (at 60 kpc) are sufficient to reduce the central density of a dSph by 80% after two passages and >99% after three.