Technical Note XLVIII
Galaxy typology, datasets, and the test groups for the component-resolved campaign
Before modelling galaxies component by component, this note fixes the experimental design: which galaxy types exist, which datasets supply them, how they are grouped for testing, the named galaxies in each group, and the exact count to be used. The validated 101 (bulgeless disks, T ≥ 4) are the baseline; the new groups extend into bulges, dwarfs and clusters.
1. Galaxy typology (by structure relevant to BeeTheory)
BeeTheory’s wave term depends on how visible mass is distributed, so the natural classification is by kinematic support and components, not by appearance alone.
| Class | Hubble T | Support | Components to model |
|---|---|---|---|
| Bulgeless disks | T ≥ 4 | rotation | stellar disk + gas disk |
| Bulged disks | T ≤ 3 | rotation | disk + gas + bulge |
| Gas-rich dwarfs (dIrr) | T = 8–11 | rotation | gas-dominated disk |
| Dwarf spheroidals (dSph) | — | dispersion | pressure-supported spheroid |
| Ellipticals / cluster galaxies | E / S0 | dispersion | spheroid (no extended HI) |
2. Datasets
SPARC alone does not cover every class — it is a disk-galaxy database. The campaign therefore draws on several catalogues:
| Dataset | Content | Used for |
|---|---|---|
| SPARC (Lelli, McGaugh, Schombert 2016) | 175 disk galaxies, S0–Irr, Spitzer [3.6] + HI rotation curves; clean subsample 153 (i ≥ 30°) | disks, bulged disks, dIrr |
| Gaia DR3 | Milky Way rotation curve (Eilers 2019; Ou 2024) | Milky Way (bulged) |
| MW dSph kinematics (Walker; Gaia DR3 PMs) | velocity dispersions of classical dwarf spheroidals | pressure-supported test |
| Cluster virial data (Coma, Virgo) | σ, R_vir, M_dyn from virial studies | cluster-scale test |
Note: dense X-ray clusters (e.g. Virgo core) are absent from SPARC because gas-poor / truncated-HI galaxies lack extended rotation curves — hence the separate cluster dataset.
3. Test groups, named galaxies, and counts
Group A — Bulgeless disks (baseline) validated
The established 101: 20 calibration + 81 blind, all T ≥ 4 from SPARC. Includes the LSB Schombert F-series that drove the ℓ_floor refinement.
Representative members: F568-1, F568-3, F571-8, NGC3198, DDO154, NGC2403, UGC2885, NGC6503, DDO064, CamB …
Count used: 101 (20 + 81).
Group B — Bulged disks to test
SPARC galaxies with T ≤ 3 (prominent bulge), plus the Milky Way via Gaia DR3. These require the 4-component decomposition (disk + thick disk + gas + bulge).
Named: Milky Way, NGC2841, NGC7814, NGC2955, NGC0891, NGC4258, NGC5055, NGC2903, NGC3521, UGC2487 … (+ the ~13 bulged SPARC galaxies in the blind pool)
Count used: ~15 (Milky Way + ~14 SPARC bulged disks).
Group C — Gas-rich dwarfs (dIrr) to test
The extreme low-mass, gas-dominated end of SPARC — strongest test of the wave term at low surface density.
Named: DDO154, DDO168, DDO126, WLM, NGC1705, UGCA442, UGC7559, DDO52, KK98-251, NGC3109 …
Count used: ~20 SPARC dIrr (T = 8–11).
Group D — Dwarf spheroidals (dispersion-supported) to test
Outside SPARC entirely: pressure-supported, no rotation curve. Tests whether the wave formalism extends to dispersion. The 8 classical Milky Way dSphs.
Named: Fornax, Sculptor, Draco, Carina, Sextans, Ursa Minor, Leo I, Leo II
Count used: 8 classical dSphs.
Group E — Cluster scale to test
The regime where MOND is weakest; pure independent check. Virial data, not rotation curves.
Named: Coma Cluster, Virgo Cluster
Count used: 2 clusters.
4. Total sample for the calculation campaign
| Group | Class | Source | Count | Status |
|---|---|---|---|---|
| A | Bulgeless disks | SPARC | 101 | validated |
| B | Bulged disks | SPARC + Gaia DR3 | 15 | new |
| C | Gas-rich dwarfs | SPARC | 20 | new |
| D | Dwarf spheroidals | MW satellites | 8 | new |
| E | Clusters | virial data | 2 | new |
| Total campaign | 146 | — | ||
101 already validated (Group A); 45 new objects across four new groups (B–E) extend the test into bulges, gas-rich dwarfs, dispersion-supported systems, and cluster scales — for a total of 146. Each is modelled by its true components with the same wave mechanism. Groups C and D probe low surface density (where ℓ_floor matters most); B probes bulge geometry; E is an independent check in MOND’s weak regime.
Counts for the new groups are target sizes drawn from data availability (extended HI for disks, published dispersions for dSphs, virial estimates for clusters). The exact SPARC bulged and dIrr counts will be finalized when the rotation-curve quality cuts (inclination i ≥ 30°, quality flag) are applied to each candidate.
BeeTheory.com — Galaxy typology, datasets and test groups · Initial generation: 21 May 2026 with Claude.ai · © Technoplane S.A.S. 2026