An Empirical Relaxation Sequence Across the Full SPARC Disk-Galaxy Population

Empirical Relaxation Classes of Disk Galaxies from the Full SPARC Sample Description:This dataset accompanies the Empirical Relaxation Framework and provides a complete, machine-readable catalog of inner dynamical relaxation states for 175 disk galaxies from the SPARC database. Using strictly empirical, model-light diagnostics derived from observed rotation curves, we define a dimensionless relaxation parameter η=Vinner(2.5 kpc)/Vref(2.5 kpc),\eta = V_{\mathrm{inner}}(2.5\,\mathrm{kpc}) / V_{\mathrm{ref}}(2.5\,\mathrm{kpc}),η=Vinner(2.5kpc)/Vref(2.5kpc), which quantifies deviations of the inner rotation curve from a collisionless reference expectation.Based on η\etaη, each galaxy is assigned to one of five empirical relaxation classes (R-I to R-V), representing a continuous dynamical sequence from collisionless-like systems to strongly relaxed, dwarf-like systems. The catalog includes: Galaxy identifiers (SPARC) Observed outer velocities VflatV_{\mathrm{flat}}Vflat Inner rotation-curve shape proxies Empirical relaxation parameters (η\etaη, log⁡τ\log\taulogτ) Explicit relaxation class assignments for every galaxy Key findings supported by this dataset: Disk galaxies do not separate into a binary “core vs. cusp” population, but populate a continuous relaxation sequence The majority of systems occupy an intermediate relaxation regime, while strongly relaxed and collisionless-like systems form well-defined extremes The relaxation state provides additional information beyond mass or velocity scaling, indicating that inner halo structure is best described as a dynamical state, not a fixed type All quantities are derived directly from observed rotation curves with minimal assumptions, enabling full reproducibility and independent re-analysis.This dataset is intended for use in studies of dark matter phenomenology, galaxy dynamics, rotation-curve diversity, and empirical tests of relaxation or self-interaction scenarios. This work uses the relaxation parameter η as defined in Riolo (2026), canonical definition and data release: https://doi.org/10.5281/zenodo.18488426 Contextual Update:The interpretation limits and regime-dependence of the empirical dynamical-state construction are discussed in Riolo (2026), DOI: https://doi.org/10.5281/zenodo.18653714.