{
  "abstract": "We present a multiwavelength radio study of the changing-look AGN 1ES 1927+654 following its renewed X-ray brightening since mid-2022, combining VLBA imaging with multi-band and time-resolved VLA observations. Our main results are: (i) VLBA observations continue to reveal the bipolar jet structure first reported in Meyer et al. (2025), with new X-band detections confirming the morphology at larger separation and K-band imaging revealing a bridge of emission consistent with a continuous outflow; (ii) the VLBA core exhibits a GHz-peaked spectrum, and VLA/VLITE observations from 340 MHz to 45 GHz show emission from an inhomogeneous synchrotron source, self-absorbed below ~3 GHz and optically thin above; (iii) VLA and VLBA flux densities are consistent above 8 GHz, indicating emission dominated by a compact core; (iv) linear polarization is detected above ~3 GHz, with fractional polarization increasing with frequency from ~0.2% to ~6% and EVPAs exhibiting non-linear lambda^2 behavior; (v) long-term VLA X-band monitoring reveals a large, smooth rotation of the EVPA of ~137 degrees over ~81 days in 2026, followed by a partial return, at stable total intensity and suppressed fractional polarization <~1.4%, consistent with a propagating disturbance crossing the compact emitting region; and (vi) circular polarization is not detected at any epoch. These observations demonstrate that 1ES 1927+654 has transitioned from an X-ray-dominated, non-jetted state to a radio-loud AGN (Laha et al. 2025) hosting a newly launched relativistic jet, a unique laboratory for studying jet birth and early magnetic field evolution.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.09539",
  "author_total": 13,
  "authors": [
    {
      "name": "Onic I. Shuvo"
    },
    {
      "name": "Eileen T. Meyer"
    },
    {
      "name": "Sibasish Laha"
    },
    {
      "name": "Agniva Roychowdhury"
    },
    {
      "name": "Dev R. Sadaula"
    },
    {
      "name": "Tracy E. Clarke"
    },
    {
      "name": "Wendy M. Peters"
    },
    {
      "name": "Mitchell C. Begelman"
    },
    {
      "name": "Markos Georganopoulos"
    },
    {
      "name": "Rostom Mbarek"
    },
    {
      "name": "Amelia M. Hankla"
    },
    {
      "name": "Alexander Philippov"
    },
    {
      "name": "Navin Sridhar"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/ej28s1s5d0nnw.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.09539",
  "fulltext_url": null,
  "id": "ej28s1s5d0nnw",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.09539",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.GA"
    ],
    [
      "arxiv",
      "astro-ph.HE"
    ],
    [
      "openalex",
      "3103|Astrophysical Phenomena and Observations"
    ]
  ],
  "openalex": "W7212152933",
  "pdf_url": "https://arxiv.org/pdf/2609.09539",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-10",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/ej28s1s5d0nnw.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:29:06Z",
      "native_id": "2609.09539",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.09539"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.HE",
      "subfield": "high-energy-astrophysics"
    }
  ],
  "title": "First Detection of Radio Polarization During Jet Formation in the Changing-Look AGN 1ES 1927+654",
  "title_text": "First Detection of Radio Polarization During Jet Formation in the Changing-Look AGN 1ES 1927+654",
  "type": "preprint",
  "updated_at": "2026-10-30T12:29:06Z",
  "url": "https://research.draconitic.com/paper/ej28s1s5d0nnw",
  "venue": "arXiv",
  "versions": []
}