{
  "id": "2309.07953",
  "version": "v1",
  "published": "2023-09-14T18:00:01.000Z",
  "updated": "2023-09-14T18:00:01.000Z",
  "title": "Magnetic field evolution in high and low $β$ disks",
  "authors": [
    "Payton E. Rodman",
    "Christopher S. Reynolds"
  ],
  "comment": "16 pages, 11 figures, submitted to Apj",
  "categories": [
    "astro-ph.HE",
    "astro-ph.SR"
  ],
  "abstract": "We present results from a pair of high resolution, long timescale ($\\sim10^5 GM/c^3$), global, three dimensional magnetohydrodynamical accretion disk simulations with differing initial magnetic plasma $\\beta$ in order to study the effects of initial toroidal field strength on production of large-scale poloidal field. We initialize our disks in approximate equilibrium with purely toroidal magnetic fields of strength $\\beta_0=5$ and $\\beta_0=200$. We also perform a limited resolution study. We find that simulations of differing field strength diverge early in their evolution and remain distinct over the time studied, indicating that initial magnetic conditions leave a persistent imprint in our simulations. Neither simulation enters the Magnetically Arrested Disk (MAD) regime. Both simulations are able to produce poloidal fields from initially-toroidal fields, with the $\\beta_0=5$ simulation evolving clear signs of a large-scale poloidal field. We make a cautionary note that computational artifacts in the form of large-scale vortices may be introduced in the combination of initially-weak field and disk-internal mesh refinement boundaries, as evidenced by the production of an $m=1$ mode overdensity in the weak field simulation. Our results demonstrate that the initial toroidal field strength plays a vital role in simulated disk evolution for the models studied.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2023-09-14T18:00:01.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "magnetic field evolution",
      "field strength diverge",
      "large-scale poloidal field",
      "initial toroidal field strength plays",
      "dimensional magnetohydrodynamical accretion disk simulations"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 16,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}