{
  "abstract": "The line spread function (LSF) of a spectrograph encodes the inherent broadening of a single spectral line. It is typically reported as a single number, the resolving power $R = λ/Δλ$ with $Δλ$ the FWHM of the LSF. In standard pipelines for extracting stellar kinematics the LSF is assumed to be a wavelength dependent Gaussian. However, detailed LSF measurements from real integral field spectrographs reveal a variety of shapes, some close to Gaussian, others with large wings or that appear boxy. I have studied the impact that these non-Gaussian LSF profiles have on the recovery of the stellar kinematics of a mock spectrum based on MUSE ($σ_{\\rm inst} = 51 $ km s$^{-1}$) and find that even in the high dispersion case of 300 km s$^{-1}$, there is up to a 7 percent bias in the dispersion due to non-Gaussian LSF profiles. Additionally, higher order Gauss-Hermite moments $h_3$ and $h_4$ can be biased by up to $\\pm$0.1. To resolve this bias, I developed a method to match the LSF of the template spectra to the LSF of a target spectrum when the LSF of either one or both is non-Gaussian and show that it can reduce bias in the dispersion to less than a percent down to the instrumental resolution. A Python implementation of this method has been made publicly available.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2606.30129",
  "author_total": 1,
  "authors": [
    {
      "name": "David A. Simon"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/0ez27e6807ym3.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2606.30129",
  "fulltext_url": null,
  "id": "0ez27e6807ym3",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2606.30129",
  "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": null,
  "pdf_url": "https://arxiv.org/pdf/2606.30129",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-27",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/0ez27e6807ym3.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:19:48Z",
      "native_id": "2606.30129",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2606.30129"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    }
  ],
  "title": "The Impact of Non-Gaussian Line Spread Functions on Stellar Kinematic Recovery: Consequences for Dynamical Models",
  "title_text": "The Impact of Non-Gaussian Line Spread Functions on Stellar Kinematic Recovery: Consequences for Dynamical Models",
  "type": "preprint",
  "updated_at": "2026-10-30T12:19:48Z",
  "url": "https://research.draconitic.com/paper/0ez27e6807ym3",
  "venue": "arXiv",
  "versions": [
    {
      "doi": "10.33232/001c.168763",
      "pid": null,
      "relation": "published-as",
      "title": null,
      "venue": null
    }
  ]
}