{
  "id": "2205.05721",
  "version": "v1",
  "published": "2022-05-11T18:33:39.000Z",
  "updated": "2022-05-11T18:33:39.000Z",
  "title": "Investigating the nature and properties of MAXI J1810-222 with radio and X-ray observations",
  "authors": [
    "T. D. Russell",
    "M. Del Santo",
    "A. Marino",
    "A. Segreto",
    "S. E. Motta",
    "A. Bahramian",
    "S. Corbel",
    "A. D'Aì",
    "T. Di Salvo",
    "J. C. A. Miller-Jones",
    "C. Pinto",
    "F. Pintore",
    "A. Tzioumis"
  ],
  "comment": "15 pages, 8 figures, 5 tables, accepted for publication in MNRAS",
  "doi": "10.1093/mnras/stac1332",
  "categories": [
    "astro-ph.HE"
  ],
  "abstract": "We present results from radio and X-ray observations of the X-ray transient MAXI J1810-222. The nature of the accretor in this source has not been identified. In this paper, we show results from a quasi-simultaneous radio and X-ray monitoring campaign taken with the Australia Telescope Compact Array (ATCA), the Neil Gehrels Swift observatory X-ray telescope (XRT), and the Swift Burst Alert Telescope (BAT). We also analyse the X-ray temporal behaviour using observations from the Neutron star Interior Composition Explorer (NICER). Results show a seemingly peculiar X-ray spectral evolution of MAXI J1810-222 during this outburst, where the source was initially only detected in the soft X-ray band for the early part of the outburst. Then, ~200 days after MAXI J1810-222 was first detected the hard X-ray emission increased and the source transitioned to a long-lived (~1.5 years) bright, harder X-ray state. After this hard state, MAXI J1810-222 returned back to a softer state, before fading and transitioning again to a harder state and then appearing to follow a more typical outburst decay. From the X-ray spectral and timing properties, and the source's radio behaviour, we argue that the results from this study are most consistent with MAXI J1810-222 being a relatively distant ($\\gtrsim$6 kpc) black hole X-ray binary. A sufficiently large distance to source can simply explain the seemingly odd outburst evolution that was observed, where only the brightest portion of the outburst was detectable by the all-sky X-ray telescopes.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2022-05-11T18:33:39.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "x-ray observations",
      "peculiar x-ray spectral evolution",
      "gehrels swift observatory x-ray telescope",
      "properties",
      "neutron star interior composition explorer"
    ],
    "tags": [
      "journal article"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 15,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}