{
  "id": "2305.16447",
  "version": "v1",
  "published": "2023-05-25T19:47:39.000Z",
  "updated": "2023-05-25T19:47:39.000Z",
  "title": "Simulations of dynamo action in slowly rotating M dwarfs: Dependence on dimensionless parameters",
  "authors": [
    "C. A. Ortiz-Rodríguez",
    "P. J. Käpylä",
    "F. H. Navarrete",
    "D. R. G Schleicher",
    "R. E. Mennickent",
    "J. P. Hidalgo",
    "B. Toro"
  ],
  "comment": "11 pages, 12 figures, submitted to A&A",
  "categories": [
    "astro-ph.SR"
  ],
  "abstract": "The aim of this study is to explore the magnetic and flow properties of fully convective M dwarfs as a function of rotation period Prot and magnetic Reynolds ReM and Prandlt numbers PrM. We performed three-dimensional simulations of fully convective stars using a star-in-a-box setup. This setup allows global dynamo simulations in a sphere embedded in a Cartesian cube. The equations of non-ideal magnetohydrodynamics were solved with the Pencil Code. We used the stellar parameters of an M5 dwarf with 0.21M_odot at three rotation rates corresponding to rotation periods (Prot): 43, 61 and 90 days, and varied the magnetic Prandtl number in the range from 0.1 to 10. We found systematic differences in the behaviour of the large-scale magnetic field as functions of rotation and PrM. For the simulations with Prot = 43 days and PrM <= 2, we found cyclic large-scale magnetic fields. For PrM > 2 the cycles vanish and field shows irregular reversals. In simulations with Prot = 61 days for PrM <= 2 the cycles are less clear and the reversal are less periodic. In the higher-PrM cases, the axisymmetric mean field shows irregular variations. For the slowest rotation case with Prot = 90 days, the field has an important dipolar component for PrM <= 5. For the highest PrM the large-scale magnetic field is predominantly irregular at mid-latitudes, with quasi-stationary fields near the poles. For the simulations with cycles, the cycle period length slightly increases with increasing ReM.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2023-05-25T19:47:39.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "simulations",
      "dynamo action",
      "dimensionless parameters",
      "large-scale magnetic field",
      "slowly rotating"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 11,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}