{
  "abstract": "We present the long-term rotational evolution and radio emission properties of the magnetar Swift J1818.0−1607, using simultaneous 2.25/8.60 GHz observations obtained with the Shanghai Tian Ma Radio Telescope from MJD 58936 to 59427. The average pulse profiles exhibit significant evolution with time and frequency, attributable to relative changes in the leading, central, and trailing emission components. The magnetar generally spins down with an average rate of −1.65(4) × 10−11 s−2, with the magnitude of the spin-down rate first increasing and then decreasing over the monitoring span. The overall flux density shows an initial rise followed by a decline, with sporadic variability superimposed; the variations at 2.25 and 8.60 GHz are broadly consistent across most epochs. The two-point spectral index increased from α ≃ −1.8 shortly after the outburst to near-zero values around MJD 59030–59050, followed by repeated decreases and increases. Despite this variability, 41 of the 54 two-point spectral-index measurements in the later campaign have α > −1. Three component-dependent types of mode changing are identified: Type I, involving primarily intensity changes in the central component; Type II, involving central and trailing components; and Type III, involving leading and central components. All three classes include events showing a corresponding component response in the other observing band, with event-dependent response strengths and directions. Type I variations are generally more pronounced at 8.60 GHz than at 2.25 GHz.",
  "abstract_shown": true,
  "affiliations": [
    "School of Optoelectronic Information Engineering, Hubei University of Education , Wuhan 430205 ,",
    "Institute of Astronomy and High Energy Physics, Hubei University of Education , Wuhan 430205 ,",
    "Shanghai Astronomical Observatory, Chinese Academy of Sciences , Shanghai 200030 ,",
    "School of Astronomy and Space Sciences, University of Chinese Academy of Sciences , Beijing 100049 ,",
    "State Key Laboratory of Radio Astronomy and Technology, Shanghai Astronomical Observatory, Chinese Academy of Sciences , Shanghai 200030 ,",
    "School of Physics and Materials Science Department of Astronomy, , Guangzhou University, Guangzhou 510006 ,",
    "University of Chinese Academy of Sciences , Beijing 100049 ,",
    "School of Information Engineering, Sanming University , Sanming 365004 ,",
    "School of Physical Science and Technology , ShanghaiTech University, Shanghai 201210 ,",
    "College of Science, Shanghai University , Shanghai 200444 ,"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 14,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Zhi-Peng Huang"
    },
    {
      "affs": [
        2,
        3,
        4
      ],
      "name": "Zhen Yan"
    },
    {
      "affs": [
        2,
        3,
        4
      ],
      "name": "Zhi-Qiang Shen"
    },
    {
      "affs": [
        5
      ],
      "name": "Hao Tong",
      "orcid": "0000-0001-7120-4076"
    },
    {
      "affs": [
        6
      ],
      "name": "Wei-Yang Wang",
      "orcid": "0000-0001-9036-8543"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Xiao-Yu Lai",
      "orcid": "0000-0002-3093-8476"
    },
    {
      "affs": [
        2,
        4
      ],
      "name": "Rong-Bing Zhao"
    },
    {
      "affs": [
        2,
        4
      ],
      "name": "Ya-Jun Wu"
    },
    {
      "affs": [
        7
      ],
      "name": "Rui Wang"
    },
    {
      "affs": [
        2,
        3
      ],
      "name": "Xiao-Wei Wang"
    },
    {
      "affs": [
        2,
        8
      ],
      "name": "Fan Yang"
    },
    {
      "affs": [
        2,
        3
      ],
      "name": "Chu-Yuan Zhang"
    },
    {
      "affs": [
        2,
        3
      ],
      "name": "Zhen-Long Liao"
    },
    {
      "affs": [
        2,
        9
      ],
      "name": "Yang-Yang Lin"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/1g3y2nyxv7qvv.bib",
  "cited_by": 0,
  "doi": "10.1093/mnras/stag2092",
  "fulltext_url": null,
  "id": "1g3y2nyxv7qvv",
  "issns": [
    "0035-8711",
    "1365-2966"
  ],
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  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [],
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  "pdf_url": "https://academic.oup.com/mnras/advance-article-pdf/doi/10.1093/mnras/stag2092/73037086/stag2092.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-04",
  "publisher": "Oxford University Press (OUP)",
  "ris": "https://research.draconitic.com/paper/1g3y2nyxv7qvv.ris",
  "sources": [
    {
      "first_seen": "2026-11-05T00:20:45Z",
      "native_id": "10.1093/mnras/stag2092",
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      "url": "https://academic.oup.com/mnras/advance-article/doi/10.1093/mnras/stag2092/9012727"
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  "subjects": [
    {
      "field": "astronomy",
      "origin": "journal-openalex:3103|Stellar, planetary, and galactic studies",
      "subfield": "stellar"
    }
  ],
  "title": "Extended 2.25/8.60 GHz Observations of the Magnetar Swift J1818.0−1607",
  "title_text": "Extended 2.25/8.60 GHz Observations of the Magnetar Swift J1818.0−1607",
  "type": "peer-reviewed",
  "updated_at": "2026-11-05T00:20:45Z",
  "url": "https://research.draconitic.com/paper/1g3y2nyxv7qvv",
  "venue": "Monthly Notices of the Royal Astronomical Society",
  "versions": []
}