{
  "abstract": "Fast radio bursts (FRBs) are millisecond-duration radio transients whose emission mechanism remains an open question. The so-called synchrotron maser instability in relativistic magnetized shocks is a leading candidate for FRBs produced outside the compact object magnetosphere, yet its spectral and polarization predictions have not been systematically explored. We present three-dimensional particle-in-cell simulations of relativistic magnetized pair plasma shocks with upstream magnetization $σ> 1$ and bulk Lorentz factor $γ_0 = 10$, assuming a plane-parallel shock geometry and neglecting radiative cooling, and compute the spectra and polarization of the precursor maser emission for an arbitrary line of sight. For on-axis observers aligned with the shock-propagation direction, the X-mode dominates the emission. The O-mode power increases at off-axis viewing angles and is primarily associated with currents parallel to the upstream background magnetic field. Assuming a spherical shock, we find full-width-at-half-maximum fractional bandwidths of $Δν/ν_0\\simeq0.57$ and $0.82$ for $σ=3$ and $6$, respectively. For highly magnetized shocks, the intrinsic emission bandwidth accounts for most of the spectral width, while high-latitude contributions provide additional broadening. The integrated emission remains highly linearly polarized near the spectral peak, with a nearly constant polarization angle due to the dominance of the X-mode. Our results suggest that synchrotron maser emission can produce spectra with bandwidths and high linear polarization degrees compatible with observations of some non-repeating FRBs, and may provide testable signatures for distinguishing shock-powered FRBs from other emission mechanisms.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.30494",
  "author_total": 3,
  "authors": [
    {
      "name": "Yuanhong Qu"
    },
    {
      "name": "Joonas Nättilä"
    },
    {
      "name": "Lorenzo Sironi"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/15qh6txd3zeg5.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.30494",
  "fulltext_url": null,
  "id": "15qh6txd3zeg5",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.30494",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.HE"
    ],
    [
      "openalex",
      "3103|Gamma-ray bursts and supernovae"
    ]
  ],
  "openalex": "W7214617587",
  "pdf_url": "https://arxiv.org/pdf/2609.30494",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-24",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/15qh6txd3zeg5.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:24:52Z",
      "native_id": "2609.30494",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.30494"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.HE",
      "subfield": "high-energy-astrophysics"
    }
  ],
  "title": "Spectral and Polarization Properties of Coherent Radio Emission from Relativistic Magnetized Pair Plasma Shocks",
  "title_text": "Spectral and Polarization Properties of Coherent Radio Emission from Relativistic Magnetized Pair Plasma Shocks",
  "type": "preprint",
  "updated_at": "2026-10-30T12:24:52Z",
  "url": "https://research.draconitic.com/paper/15qh6txd3zeg5",
  "venue": "arXiv",
  "versions": []
}