Left: dependence of the molecular gas mass in PHANGS central rings on the bar length. Data points are color-coded by their host galaxies’ stellar mass M_*^gal. Right: Dependence of the relative ring molecular gas content on the relative bar length, color-coded by their host galaxies’ gas fraction $(M_{\mathrm{mol}}+M_{\mathrm{atomic}}^{\mathrm{gal}})/M_{\ast }^{\mathrm{gal}}$. The blue line is a linear fit to the data, obtained with the Python tool scipy.optimize.curve_fit. In both panels, the symbols follow Fig. 1 (barred spiral = diamond, barred ETGs = cross) and the Pearson correlation coefficients are provided in the bottom right.