{
  "abstract": "Dark matter halos exhibit slow tumbling known as “figure rotation.” Figure rotation occurs in roughly 80% of isolated ΛCDM halos and is relatively unaffected by baryonic feedback, making it an attractive and relatively unexplored test for ΛCDM. However, galaxy mergers are capable of exerting strong torques on a host halo’s quadrupole, warranting an investigation of whether such interactions are capable of influencing figure rotation. Using isolated N- body simulations and six TNG50 halos containing Milky Way analog galaxies, we investigate figure rotation in the context of massive mergers. For isolated galaxies we find that massive mergers elicit rotation of the host halo in both a rapid transient phase during the satellite infall with pattern speeds between 10° and 60° Gyr ⁻¹ , and postmerger as a steady tumbling with pattern speeds between 2° and 40° Gyr ⁻¹ lasting for at least 6–8 Gyr. Both transient and long-lived tumbling depend on the trajectory of the infalling satellite. We find that figure rotation can be induced by radial mergers with no orbital angular momentum, suggesting that tidal torques from the satellite are a driving mechanism. Meanwhile, quadrupole tumbling in TNG50 halos is modified in both pattern speed (3/6 halos) and rotation axis orientation (6/6 halos) during major mergers. Quadrupole tumbling remains stable after the last major merger in five of our six halos. Our results suggest that, rather than tracing the early tidal shear, figure rotation at present day may instead retain a dynamical memory of a halo’s last major merger.",
  "abstract_shown": true,
  "affiliations": [
    "University of Michigan"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 2,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Neil Ash",
      "orcid": "0009-0003-7613-3109"
    },
    {
      "affs": [
        0
      ],
      "name": "Monica Valluri",
      "orcid": "0000-0002-6257-2341"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/2trbptvat5g2k.bib",
  "cited_by": 0,
  "doi": "10.3847/1538-4357/aea14d",
  "fulltext_url": null,
  "id": "2trbptvat5g2k",
  "issns": [
    "0004-637X",
    "1538-4357"
  ],
  "landing_url": "https://iopscience.iop.org/article/10.3847/1538-4357/aea14d",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "3103|Galaxies: Formation, Evolution, Phenomena"
    ]
  ],
  "openalex": "W7207779335",
  "pdf_url": "https://iopscience.iop.org/article/10.3847/1538-4357/aea14d/pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-30",
  "publisher": "American Astronomical Society",
  "ris": "https://research.draconitic.com/paper/2trbptvat5g2k.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:11Z",
      "native_id": "10.3847/1538-4357/aea14d",
      "source": "crossref",
      "url": "https://iopscience.iop.org/article/10.3847/1538-4357/aea14d"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "openalex:3103|Galaxies: Formation, Evolution, Phenomena",
      "subfield": "galaxies"
    }
  ],
  "title": "Dark Matter Halo Tumbling Induced by Torques from Massive Mergers",
  "title_text": "Dark Matter Halo Tumbling Induced by Torques from Massive Mergers",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:11Z",
  "url": "https://research.draconitic.com/paper/2trbptvat5g2k",
  "venue": "The Astrophysical Journal",
  "versions": []
}