Maps of torques created by stars younger than 2 Gyr (top) and by stars older than that age (bottom) at different simulated times (columns). Bottom panels include stars with ages up to 4.9, 7.8, and 12.7 Gyr from left to right. Stars inside 4 kpc were azimuthally shuffled before computing the torques. The colour coding follows an inverse hyperbolic sine scale. Dashed and solid lines indicate the 1.9 and 2 thresholds of the local dimension from stars younger than 0.5 Gyr at the corresponding time.