Expansion and age estimate for RX J1713.7−3946. Top panel: measured maximal proper motion μ_exp of filaments in the expanding shell versus their angular distance ϑ from the explosion site. We indicate values from the literature for the southeast (Acero et al. 2017), northwest (Tsuji & Uchiyama 2016), and southwest (Tanaka et al. 2020) regions, respectively. For the proper motion, we display the error bars as given in the respective paper, scaled to 68% confidence and including systematic errors for Acero et al. (2017). Bottom panel: derived likelihood and corresponding 90% confidence upper limits for the undecelerated expansion age τ, inferred for the respective filaments.