Empirical Re-analysis of Galaxy Rotation Curves in the SPARC Sample

This record contains an updated version of the empirical analysis of galaxy rotation curves based on the SPARC database. The study re-examines the structure of outer rotation-curve slopes and the radial acceleration relation using the full SPARC galaxy sample. Outer slopes are measured using log–log linear regression in the region R > 2.5 Rdisk with quality selection Q ≤ 2. The analysis shows that the distribution of outer slopes is centred near zero and exhibits internal structure rather than purely random scatter. A sliding-window reconstruction of the Radial Acceleration Relation (RAR) further reveals a continuous dynamical transition between inner baryon-dominated regions and an outer asymptotic regime. The accompanying supplementary material provides the full data-processing pipeline, algorithmic steps, and reproducibility instructions required to repeat the analysis directly from the publicly available SPARC data. All calculations are based on the SPARC database: Lelli, McGaugh & Schombert (2016) SPARC: Mass Models for 175 Disk Galaxies with Spitzer Photometry and Accurate Rotation Curves. No modification of the observational data is performed. All measurements are derived directly from the publicly available SPARC observational files.