AI Clustering of ALMA ISM �& Star Formation Data
Yun-Chi Wang(NTU)
Supervisor : Dr. Tien-Hao Hsieh (TARA)
Background
The Atacama Large Millimeter/submillimeter Array (ALMA)
George Kosugi, Eisuke Morita, Hiroshi Yoshida, et al. "Implementation and cost estimation of ALMA archive using cloud technology", Proc. SPIE 14155, Software and Cyberinfrastructure for Astronomy IX, 1415544 (19 Aug 2026); https://doi.org/10.1117/12.3104417
Background
Methodology
http://iopscience.iop.org/article/10.1086/671105
VICReg
https://doi.org/10.48550/arXiv.2105.04906
Umap Cluster
interpret clusters physically
Methodology-UMAP
Dimension /Criterion | PCA | t-SNE | UMAP | Astrophysical Impact for ALMA |
Manifold Geometry | Linear only | Non-linear | Non-linear | Captures complex velocity fields and varied emission morphologies |
Global Structure | Preserved | Lost (local only) | Preserved | Preserves evolutionary connections |
New Data Projection | Yes | No (requires full rerun) | Yes | Instantly projects future ALMA cycles without retraining |
Cluster Morphology | Heavy overlap | Scattered clumps | Distinct "Islands" | Isolates clean physical archetypes (Disks, Outflows, Filaments) |
Verification Labled Sample
Keplerian disks
outflows
Moment 0
(Symmetric Intensity)
Moment 0
(Collimated Lobes)
Moment 1
(Butterfly Velocity Gradient)
Moment 1
(Red/Blue-shifted
High-Velocity Wings)
Curated benchmark of ~100 known astrophysical sources used to validate unsupervised clustering.
UMAP
Min_dist
0.1
0.5
0.9
n_neighbors
20
50
100
🔴 Infall
🟩 Keplerian Disk ➕ Outflow
✖️ Point Source 🔶 Filament
🟡 Jet
Issue with primary beam correction
Without primary beam correction
PCA : technique that rotates the high-dimensional space to find the orthogonal axes of maximum variance
Measures total signal power
PC1
PC2
Umap of right island
orthogonal projection
project our vector onto the subspace that is strictly orthogonal to the PC1.
Conclusions
Future work
Back-up slides
morphology of disks
morphology of outflows
morphology of infall
morphology of jet
morphology of filaments
morphology of point sources
Domain Variance Removal via Orthogonal Projection