The Role of Dark Matter in Driving Disk Perturbations: Application to LMC-SMC Like Galaxy Interactions

@misc{rathore2026role,
  title = {{The Role of Dark Matter in Driving Disk Perturbations: Application to LMC-SMC Like Galaxy Interactions}},
  author = {Himansh Rathore and Hayden R. Foote and Gurtina Besla and Silvio Varela-Lavin and Nicolas Garavito-Camargo and Martin D. Weinberg and Facundo A. Gomez and Kathryne J. Daniel and Chervin F. P. Laporte},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2609.07867},
  eprint = {2609.07867},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.07867},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - The Role of Dark Matter in Driving Disk Perturbations: Application to LMC-SMC Like Galaxy Interactions
AU  - Himansh Rathore
AU  - Hayden R. Foote
AU  - Gurtina Besla
AU  - Silvio Varela-Lavin
AU  - Nicolas Garavito-Camargo
AU  - Martin D. Weinberg
AU  - Facundo A. Gomez
AU  - Kathryne J. Daniel
AU  - Chervin F. P. Laporte
PY  - 2026
DA  - 2026/10/04
PB  - arXiv
DO  - 10.48550/arxiv.2609.07867
UR  - https://arxiv.org/abs/2609.07867
AB  - Dark-matter (DM) models predict that satellite galaxies distort their host's DM halo. As such, both the satellite and the distorted halo can perturb the host's stellar disk. The LMC-SMC system is a nearby ∼1:10~mass-ratio binary with a well-constrained orbit and well-characterized LMC disk perturbations. Hence, the system offers unique opportunities to test DM theory, provided the impact of halo torques on the LMC's disk can be characterized along with the SMC's torques. We use halo Basis Function Expansions (BFEs) of an N-body simulation of an isolated LMC-SMC-like interaction to quantify the time-dependent torques exerted on the LMC's disk by the SMC and the LMC's DM halo. We find that the halo torques arise from the quadrupole halo distortion, and the inner (R<6 kpc) LMC disk warps are the most promising probe of this quadrupole. For the first time, we construct a BFE to quantify the LMC's disk perturbations resulting from the SMC and halo torques. We find that the LMC's disk is significantly perturbed prior to the Clouds' Milky Way infall, possessing warps with a mean vertical extent of ∼1 kpc. Finally, we apply multi-channel singular spectral analysis (mSSA) to the time-series of the disk BFE coefficients, halo quadrupole, and the LMC-SMC orbit. mSSA successfully separates the temporal evolution of the LMC warps into components correlated with the halo versus the SMC. Our framework identifies correlated evolution between the LMC's halo distortions and the LMC's disk perturbations, enabling the Clouds to be a precision laboratory for DM physics.
ER  -