{
  "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 $α_{\\mathrm{nth}}$ and the SFR surface density $Σ_{\\mathrm{SFR}}$. All 19 galaxies exhibit statistically significant nonthermal spectral flattening with increasing $Σ_{\\mathrm{SFR}}$, with a sample median slope of $0.19_{-0.03}^{+0.09}$ 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 $α_{\\mathrm{nth}}$-$Σ_{\\mathrm{SFR}}$ 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 $α_{\\mathrm{nth}}$ 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": [],
  "article_type": null,
  "arxiv": "2609.33211",
  "author_total": 9,
  "authors": [
    {
      "name": "Jianghui Xu"
    },
    {
      "name": "Volker Heesen"
    },
    {
      "name": "Jiang-Tao Li"
    },
    {
      "name": "Guilin Liu"
    },
    {
      "name": "Rainer Beck"
    },
    {
      "name": "Li-Yuan Lu"
    },
    {
      "name": "Yang Yang"
    },
    {
      "name": "Jayanne English"
    },
    {
      "name": "Shengtao Wang"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/ecj5gbkpq2mhe.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.33211",
  "fulltext_url": null,
  "id": "ecj5gbkpq2mhe",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.33211",
  "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"
    ],
    [
      "openalex",
      "3106|Astrophysics and Cosmic Phenomena"
    ]
  ],
  "openalex": "W7214756589",
  "pdf_url": "https://arxiv.org/pdf/2609.33211",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-27",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/ecj5gbkpq2mhe.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:25:12Z",
      "native_id": "2609.33211",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.33211"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    }
  ],
  "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": "preprint",
  "updated_at": "2026-10-30T12:25:12Z",
  "url": "https://research.draconitic.com/paper/ecj5gbkpq2mhe",
  "venue": "arXiv",
  "versions": []
}