Unified Galaxy Rotation Curve Corpus (v3.1): SPARC + THINGS + LITTLE THINGS

Unified Galaxy Rotation Curve Corpus (v3.1)SPARC + THINGS + LITTLE THINGS — Structured for Computational Astrophysics and LLM-Based InferenceFlynn, D.C. (EPS Research, Laurel MD)ORCID: 0000-0002-2768-6650Contact: [e-mail]---SummaryThis dataset provides a unified, semantically structured collection of galaxy rotation curve data drawn from three major observational surveys: SPARC (Spitzer Photometry and Accurate Rotation Curves; Lelli, McGaugh & Schombert 2016), THINGS (The HI Nearby Galaxy Survey; de Blok et al. 2008, Walter et al. 2008), and LITTLE THINGS (Local Irregulars That Trace Luminosity Extremes; Oh et al. 2015).The corpus unifies 7,217 radial measurement points across 220 galaxies (with an additional 15 THINGS galaxies retaining metadata only), applies consistent unit conventions (kpc, km/s), cross-matches 14 galaxies appearing in multiple surveys, and annotates known data-quality issues at the galaxy level. It was constructed to support both traditional numerical analysis and Large Language Model (LLM) retrieval-augmented generation (RAG) pipelines for astrophysical inference.CoverageSurvey Galaxies Data Rows Primary ReferenceSPARC 175 3,391 Lelli et al. (2016), AJ 152, 157THINGS (de Blok subset) 19 2,110 de Blok et al. (2008), AJ 136, 2648THINGS (metadata only) 15 — Walter et al. (2008), AJ 136, 2563LITTLE THINGS 26 1,716 Oh et al. (2015), AJ 149, 180Total (with data) 220 7,217 14 galaxies appear in two surveys; the crossmatch index is included in the JSON metadata.Filesrotation_curve_corpus_v3.json — Master JSONSingle JSON document containing all 235 galaxy entries in a unified schema. Top-level object includes a metadata block (title, version, creator, survey descriptions, crossmatch index) and a `galaxies` array. This is the authoritative source from which the other formats are derived.rotation_curve_corpus_v3_flat.csv — Flat TableOne row per radial measurement (7,217 rows). Columns include galaxy name, survey, distance, bulge flag, radius (kpc), and survey-specific velocity fields: SPARC provides full baryonic decomposition (Vobs, Vgas, Vdisk, Vbul, SBdisk, SBbul); THINGS and LITTLE THINGS provide tilted-ring rotation velocities (Vrot, e_Vrot). Directly loadable with pandas, R, or any tabular analysis tool.rotation_curve_corpus_v3_by_galaxy.zip — Per-Galaxy JSONZIP archive containing 235 individual JSON files organised into three subdirectories (SPARC/, THINGS/, LITTLE_THINGS/). Each file is self-contained with corpus metadata and the full galaxy object. Optimised for LLM/RAG ingestion where each galaxy constitutes a single retrieval document.Key ConventionsRadii: All radii are in kiloparsecs. THINGS radii were converted from arcseconds using R[kpc] = R[arcsec] × D[Mpc] × 1000 × π / 648000.SPARC baryonic velocities: Gas contribution Vgas may be negative at inner radii (thermal pressure exceeds rotational support). Quadrature summation uses sign-preserving convention: V_bar = sqrt(Υ★ V²_disk + Υ_b V²_bul + sign(V_gas) V²_gas). All velocity components stored at mass-to-light ratio Υ = 1.Omega correction: The corpus supports application of the empirical omega correction (Flynn & Cannaliato 2025, Frontiers in Astronomy and Space Sciences), where V_obs(R) = V_kepler(R) + R × ω. The Rad and Vobs columns provide direct inputs for this computation.Related WorkFlynn, D.C. & Cannaliato, J. (2025). "A new empirical fit to galaxy rotation curves." Frontiers in Astronomy and Space Sciences, 12. DOI: 10.3389/fspas.2025.1680387Flynn, D.C. (2025). "High-Performance Dual-Node AI Infrastructure for Astrophysics and Cybersecurity." TechRxiv. DOI: 10.36227/techrxiv.176369640.06690868/v1Data ProvenanceAll underlying rotation curve data are drawn from published, publicly available sources:SPARC: Lelli, McGaugh & Schombert (2016), AJ 152, 157 — astroweb.cwru.edu/SPARCTHINGS RC: de Blok et al. (2008), AJ 136, 2648THINGS survey: Walter et al. (2008), AJ 136, 2563 — THINGS DataLITTLE THINGS: Oh et al. (2015), AJ 149, 180 — VizieR J/AJ/149/180LicenseThe corpus (schema, normalisation, annotations, crossmatch index, and unified structure) is original work by D.C. Flynn / EPS Research and is released under CC BY 4.0.CitationIf you use this corpus, please cite:> Flynn, D.C. (2026). *Unified Galaxy Rotation Curve Corpus (v3.1): SPARC + THINGS + LITTLE THINGS.* Zenodo. DOI: 10.5281/zenodo.19425428and the relevant underlying survey papers listed above.