{
  "abstract": "Weakly-collisional plasmas are found in several turbulent astrophysical environments, such as the Intra-galaxy-cluster medium (ICM) and the solar wind, where magnetic fields can be amplified by the turbulent dynamo. The onset of dynamo action is determined by the critical magnetic Reynolds number, ${\\rm Rm}_{\\rm crit}$, above which turbulent motions amplify magnetic energy. Although ${\\rm Rm}_{\\rm crit}$ has been studied extensively in collisional magnetohydrodynamic (MHD) turbulence, its value in supersonic weakly-collisional plasmas remains unknown. Here we determine ${\\rm Rm}_{\\rm crit}$ using three-dimensional hybrid particle-in-cell (HPIC) simulations of solenoidally driven turbulence with a sonic Mach number $\\approx 2$. We vary the magnetic Reynolds number over ${\\rm Rm}\\approx31$-$1000$ and consider two initial plasma magnetisations, characterised by initial Larmor ratios $r_{\\rm Larmor, 0}/L_{\\rm box}=1$ and $100$. We find that the magnetic energy grows exponentially at sufficiently large ${\\rm Rm}$ and decays when magnetic diffusion dominates at low ${\\rm Rm}$. By fitting the magnetic-energy growth rate as a function of ${\\rm Rm}$, we measure ${\\rm Rm}_{\\rm crit}=190^{+21}_{-17}$ and $198^{+16}_{-18}$ for the initially magnetised and unmagnetised plasma, respectively. These values are the same within their uncertainties, indicating that the initial plasma magnetisation does not significantly affect ${\\rm Rm}_{\\rm crit}$ in the supersonic regime. The measured values are higher than those previously obtained for the subsonic weakly-collisional dynamo, showing that increasing compressibility makes weakly-collisional turbulent dynamo action more difficult to excite. The measured values are also approximately 1.5 times higher than the ${\\rm Rm}_{\\rm crit}$ value reported for supersonic MHD turbulence.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.24394",
  "author_total": 2,
  "authors": [
    {
      "name": "Radhika Achikanath Chirakkara"
    },
    {
      "name": "Christoph Federrath"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/4wednmvh40gc6.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.24394",
  "fulltext_url": null,
  "id": "4wednmvh40gc6",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.24394",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.CO"
    ],
    [
      "arxiv",
      "physics.plasm-ph"
    ],
    [
      "openalex",
      "3103|Solar and Space Plasma Dynamics"
    ]
  ],
  "openalex": "W7223050863",
  "pdf_url": "https://arxiv.org/pdf/2610.24394",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-17",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/4wednmvh40gc6.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:30:52Z",
      "native_id": "2610.24394",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.24394"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    },
    {
      "field": "physics",
      "origin": "arxiv:physics.plasm-ph",
      "subfield": "plasma"
    }
  ],
  "title": "Critical magnetic Reynolds number of the weakly-collisional turbulent dynamo in supersonic plasmas",
  "title_text": "Critical magnetic Reynolds number of the weakly-collisional turbulent dynamo in supersonic plasmas",
  "type": "preprint",
  "updated_at": "2026-10-30T12:33:41Z",
  "url": "https://research.draconitic.com/paper/4wednmvh40gc6",
  "venue": "arXiv",
  "versions": []
}