Fig. 1: The fundamental acceleration scale in galaxy data.
From: Presence of a fundamental acceleration scale in galaxies
a–d, The baryonic Tully–Fisher relation between the observed mass in stars and gas, Mb, and the flat rotation velocity Vf from our analysis1 (a) and that of ref. 3 (b). Blue points show high-quality data with distance uncertainties less than 20% and excluding the worst rotation curves (Q = 3 in SPARC2). Crosses show the remaining data. The data follow a line of constant a0 = 1.2 × 10–13 km s–2 (ref. 6). Each galaxy has g† = xVf4/(GMb) (ref. 8), where G is Newton’s constant and x = 0.8 accounts for the disk geometry of rotating galaxies9. The line is not a fit; it simply shows g† = a0. Scatter around this line is shown in c and d. Grey histograms include all available data; blue histograms are restricted to higher-quality data as defined above. The red histogram in d shows the fitted a0 of ref. 3.
