{
  "abstract": "Radio continuum emission traces star formation in galaxies, but cosmic-ray electron (CRE) propagation between the disk and halo complicates this connection. We present a wide-band, spatially resolved analysis of 19 nearby edge-on galaxies, combining LOFAR observations at 144 MHz with CHANG-ES VLA imaging at 1.575, 3.0, and 6.0 GHz, and hybrid H α +22 μ m star formation rate (SFR) maps. All maps are convolved to a common 2.1 kpc resolution for pixel-by-pixel analysis of the nonthermal spectral index α nth and the SFR surface density Σ SFR . All 19 galaxies exhibit statistically significant nonthermal spectral flattening with increasing Σ SFR , with a sample median slope of 0.1 9 − 0.03 + 0.09 that traces the contrast between CRE injection in the star-forming disk and cooling in the halo. The galaxy-to-galaxy scatter in this slope shows no dependence on global galaxy properties and instead appears to be modulated by the local dynamical environment, with the largest α nth –Σ SFR slopes appearing in tidally perturbed systems. The resolved radio–SFR slope steepens from 0.57 at 144 MHz to 0.95 at 6 GHz, approaching linearity at high frequencies. This trend is consistent with energy-dependent CRE cooling and transport, with the deviation from linearity most pronounced at low frequencies, where the edge-on line of sight blends midplane and halo CRE populations. These results are robust against thermal contamination, beam smearing, and spectral curvature. Together, our analysis establishes α nth as an observational probe of projected disk-to-halo CRE transport in edge-on galaxies and quantifies how this transport reshapes the frequency dependence of resolved radio–SFR calibrations.",
  "abstract_shown": true,
  "affiliations": [
    "University of Science and Technology of China",
    "Universität Hamburg",
    "Chinese Academy of Sciences",
    "Max-Planck-Institut für Radioastronomie",
    "Qinghai University",
    "Xiangtan University",
    "University of Manitoba",
    "Yunnan University"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 9,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Jianghui Xu",
      "orcid": "0009-0006-3887-8988"
    },
    {
      "affs": [
        1
      ],
      "name": "Volker Heesen",
      "orcid": "0000-0002-2082-407X"
    },
    {
      "affs": [
        2
      ],
      "name": "Jiang-Tao Li",
      "orcid": "0000-0001-6239-3821"
    },
    {
      "affs": [
        0
      ],
      "name": "Guilin Liu",
      "orcid": "0000-0003-2390-7927"
    },
    {
      "affs": [
        3
      ],
      "name": "Rainer Beck",
      "orcid": "0009-0001-8154-3562"
    },
    {
      "affs": [
        4
      ],
      "name": "Li-Yuan Lu",
      "orcid": "0000-0002-3286-5346"
    },
    {
      "affs": [
        5
      ],
      "name": "Yang Yang",
      "orcid": "0000-0001-7254-219X"
    },
    {
      "affs": [
        6
      ],
      "name": "Jayanne English",
      "orcid": "0000-0001-5310-1022"
    },
    {
      "affs": [
        7
      ],
      "name": "Shengtao Wang",
      "orcid": "0009-0003-9052-1976"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/25phms8m66x4d.bib",
  "cited_by": 0,
  "doi": "10.3847/1538-4357/aead99",
  "fulltext_url": null,
  "id": "25phms8m66x4d",
  "issns": [
    "1538-4357",
    "0004-637X"
  ],
  "landing_url": "https://iopscience.iop.org/article/10.3847/1538-4357/aead99",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "feed-journal",
      "astronomy/general"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://iopscience.iop.org/article/10.3847/1538-4357/aead99/pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-03",
  "publisher": "American Astronomical Society",
  "ris": "https://research.draconitic.com/paper/25phms8m66x4d.ris",
  "sources": [
    {
      "first_seen": "2026-11-03T12:20:16Z",
      "native_id": "10.3847/1538-4357/aead99",
      "source": "feed-iop",
      "url": "https://iopscience.iop.org/article/10.3847/1538-4357/aead99"
    },
    {
      "first_seen": "2026-11-03T12:20:32Z",
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      "source": "crossref",
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  "subjects": [
    {
      "field": "astronomy",
      "origin": "journal-openalex:3103|Stellar, planetary, and galactic studies",
      "subfield": "stellar"
    }
  ],
  "title": "CHANG-ES. XLII. Cosmic-Ray Electron Transport and the Spatially Resolved Radio–SFR Relation in Edge-on Galaxies",
  "title_text": "CHANG-ES. XLII. Cosmic-Ray Electron Transport and the Spatially Resolved Radio–SFR Relation in Edge-on Galaxies",
  "type": "peer-reviewed",
  "updated_at": "2026-11-05T00:20:44Z",
  "url": "https://research.draconitic.com/paper/25phms8m66x4d",
  "venue": "The Astrophysical Journal",
  "versions": []
}