{
  "id": "2411.10353",
  "version": "v1",
  "published": "2024-11-15T16:59:11.000Z",
  "updated": "2024-11-15T16:59:11.000Z",
  "title": "First spectropolarimetric observation of the neutron star low-mass X-ray binary GX 3+1",
  "authors": [
    "Andrea Gnarini",
    "Ruben Farinelli",
    "Francesco Ursini",
    "Stefano Bianchi",
    "Fiamma Capitanio",
    "Giorgio Matt",
    "Mason Ng",
    "Antonella Tarana",
    "Anna Bobrikova",
    "Massimo Cocchi",
    "Sergio Fabiani",
    "Philip Kaaret",
    "Juri Poutanen",
    "Swati Ravi"
  ],
  "comment": "7 pages, 6 figures, 4 tables. Accepted for publication in Astronomy & Astrophysics. arXiv admin note: text overlap with arXiv:2408.02309",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "We report the first simultaneous X-ray spectropolarimetric observation of the bright atoll neutron star low-mass X-ray binary GX 3+1, performed by the Imaging X-ray Polarimetry Explorer (IXPE) joint with NICER and NuSTAR. The source does not exhibit significant polarization in the 2-8 keV energy band, with an upper limit of 1.3% at a 99% confidence level on the polarization degree. The observed spectra can be well described by a combination of thermal disk emission, the hard Comptonization component, and reflected photons off the accretion disk. In particular, from the broad Fe K$\\alpha$ line profile, we were able to determine the inclination of the system ($i \\approx 36^\\circ$), which is crucial for comparing the observed polarization with theoretical models. Both the spectral and polarization properties of GX 3+1 are consistent with those of other atoll sources observed by IXPE. Therefore, we may expect a similar geometrical configuration for the accreting system and the hot Comptonizing region. The low polarization is also consistent with the low inclination of the system.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2024-11-15T16:59:11.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "star low-mass x-ray binary gx",
      "neutron star low-mass x-ray binary",
      "first spectropolarimetric observation",
      "atoll neutron star low-mass",
      "simultaneous x-ray spectropolarimetric observation"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 7,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}