{
  "id": "0911.3566",
  "version": "v1",
  "published": "2009-11-18T15:10:58.000Z",
  "updated": "2009-11-18T15:10:58.000Z",
  "title": "Variable precession of the neutron star in Her X-1",
  "authors": [
    "R. Staubert",
    "D. Klochkov",
    "K. Postnov",
    "N. Shakura",
    "J. Wilms",
    "R. E. Rothschild"
  ],
  "comment": "2 pages, 1 figure",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "We present evidence for an identical behavior of the precession of the accretion disk and that of the neutron star (NS) in Her X-1, based on investigating the well established 35 day modulation in Her X-1 in two different ways: 1) following the turn-ons, thought to be due to the precession of the accretion disk, and 2) following the re-appearance of the shape of the pulse profiles, which we assume to be due to precession of the NS. The turn-on evolution and the evolution of the phase-zero values of the precessing NS (as determined from the pulse profiles) track each other very closely. Since the turn-on evolution is strongly correlated with the pulse period evolution, this means that there is also a strong correlation between the spin and the precession of the NS. There is a very strong physical coupling between the NS and the accretion disk, we suggest through physical feedback in the binary system. The apparent long-term stability of the 35 d clock may be due to the interior of the NS, the coupling of which to the observable surface effects is of general importance for the physics of super-dense, highly magnetized material.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2009-11-18T15:10:58.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "97.10.Gz",
      "98.70.Qy",
      "78.70.En"
    ],
    "keywords": [
      "neutron star",
      "variable precession",
      "accretion disk",
      "pulse profiles",
      "turn-on evolution"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1063/1.3475209",
      "journal": "X-ray Astronomy 2009; Present Status, Multi-Wavelength Approach and Future Perspectives",
      "year": 2010,
      "month": "Jul",
      "volume": 1248,
      "pages": 209
    },
    "note": {
      "typesetting": "TeX",
      "pages": 2,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 837263,
      "adsabs": "2010AIPC.1248..209S"
    }
  }
}