{
  "id": "1503.07203",
  "version": "v1",
  "published": "2015-03-24T21:00:15.000Z",
  "updated": "2015-03-24T21:00:15.000Z",
  "title": "Peanuts, brezels and bananas: food for thought on the orbital structure of the Galactic bulge",
  "authors": [
    "M. Portail",
    "C. Wegg",
    "O. Gerhard"
  ],
  "comment": "Accepted for publication in MNRAS Letters",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "Recent observations have discovered the presence of a Box/Peanut or X-shape structure in the Galactic bulge. Such Box/Peanut structures are common in external disc galaxies, and are well-known in N-body simulations where they form following the buckling instability of a bar. From studies of analytical potentials and N-body models it has been claimed in the past that Box/Peanut bulges are supported by \"bananas\", or x1v1 orbits. We present here a set of N-body models where instead the peanut bulge is mainly supported by brezel-like orbits, allowing strong peanuts to form with short extent relative to the bar length. This shows that stars in the X-shape do not necessarily stream along banana orbits which follow the arms of the X-shape. The brezel orbits are also found to be the main orbital component supporting the peanut shape in our recent Made-to-Measure dynamical models of the Galactic bulge. We also show that in these models the fraction of stellar orbits that contribute to the X-structure account for 40-45% of the stellar mass.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2015-03-24T21:00:15.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "galactic bulge",
      "orbital structure",
      "n-body models",
      "external disc galaxies",
      "main orbital component"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}