{
  "id": "1109.2868",
  "version": "v1",
  "published": "2011-09-13T17:59:56.000Z",
  "updated": "2011-09-13T17:59:56.000Z",
  "title": "Unraveling the Geometry of the Crab Nebula's \"Inner Ring\"",
  "authors": [
    "Martin C. Weisskopf",
    "Ronald F. Elsner",
    "Jeffery J. Kolodziejczak",
    "Stephen L. O'Dell",
    "Allyn F. Tennant"
  ],
  "comment": "12 pages, f figures, submitted to the Astrophysical Journal",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "Chandra images of the Crab Nebula resolve the detailed structure of its \"inner ring\", possibly a termination shock where pulsar-accelerated relativistic particles begin to emit X radiation. Analysis of these images finds that the center of the ellipse-presumably a circular ring in projection-lies about 0.9\" (10 light-days at 2 kpc) from the pulsar's image, at a position angle of about 300{\\deg} (East of North). This analysis also measures properties of the ellipse: The position angle of the semi-major axis is about 210{\\deg} (East of North); the aspect ratio, 0.49. In a simple-albeit, not unique-de-projection of the observed geometry, a circular ring is centered on the axis of symmetry of the pulsar wind nebula. This ring is not equatorial but rather lies near +4.5{\\deg} latitude in pulsar-centered coordinates. Alternative geometries are briefly discussed.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2011-09-13T17:59:56.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "inner ring",
      "position angle",
      "pulsar wind nebula",
      "pulsar-accelerated relativistic particles begin",
      "crab nebula resolve"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1088/0004-637X/746/1/41",
      "journal": "The Astrophysical Journal",
      "year": 2012,
      "month": "Feb",
      "volume": 746,
      "number": 1,
      "pages": 41
    },
    "note": {
      "typesetting": "TeX",
      "pages": 12,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 927209,
      "adsabs": "2012ApJ...746...41W"
    }
  }
}