{
  "abstract": "Photochemical hazes play an important role in shaping the spectra and radiative balance of N2-dominated planetary atmospheres. We present newly acquired FTIR and retrieved optical constants (N=n+ik) of laboratory-generated haze analogs from N2/CH4 and N2/CH4/CO gas mixtures under plasma discharge conditions. The retrievals use particle densities newly measured for the CH4-series and previously published particle densities for the CO-series. The experiments systematically explored CH4 concentrations from 0.5% to 10% and CO concentrations from 0% to 5% with fixed 5% CH4. Using measured particle densities together with the Beer-Lambert law and subtractive Kramers-Kronig (SKK) relation, we derived optical constants over the 350-25000 cm-1 (0.4-28.6 μm) spectral range, with the 0.4-25 μm results presented in the main text. The infrared spectra reveal prominent absorption features associated with hydrocarbon-, nitrogen-, and oxygen-bearing functional groups. Increasing CH4 abundance enhances aliphatic hydrocarbon features and corresponds to decreasing particle density, whereas increasing CO abundance promotes oxygen incorporation, broader mid-infrared absorptions, and higher particle density. The derived k spectra exhibit strong absorptions near ~3 μm, ~4.6 μm, and ~6-10 μm, while the real refractive index n generally ranges from ~1.2 to 1.7. The controlled CH4- and CO-series establish composition-dependent variations in haze optical properties. A benchmark comparison among Titan-, Pluto-, and Triton-like haze analogs then uses these experimentally identified trends to interpret the optical differences among N2-dominated planetary haze compositions. The density and optical constants provide laboratory constraints for atmospheric radiative transfer models and for interpreting planetary and exoplanetary spectra from spacecraft and telescopes.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.22982",
  "author_total": 7,
  "authors": [
    {
      "name": "Zhengbo Yang"
    },
    {
      "name": "Chao He"
    },
    {
      "name": "Haixin Li"
    },
    {
      "name": "Sai Wang"
    },
    {
      "name": "Xiao'ou Luo"
    },
    {
      "name": "Yu Liu"
    },
    {
      "name": "Sarah M. Hörst"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/37yx3tce476sw.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.22982",
  "fulltext_url": null,
  "id": "37yx3tce476sw",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.22982",
  "language": null,
  "licence": "CC-BY-SA-4.0",
  "licence_label": "CC BY-SA 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by-sa/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.EP"
    ],
    [
      "openalex",
      "3103|Astro and Planetary Science"
    ]
  ],
  "openalex": "W7214003284",
  "pdf_url": "https://arxiv.org/pdf/2609.22982",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-19",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/37yx3tce476sw.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:23:19Z",
      "native_id": "2609.22982",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.22982"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.EP",
      "subfield": "planetary"
    }
  ],
  "title": "Optical Constants of Photochemical Haze Analogs in N2-CH4-CO Atmospheres from 0.4 to 28.6 μm",
  "title_text": "Optical Constants of Photochemical Haze Analogs in N2-CH4-CO Atmospheres from 0.4 to 28.6 μm",
  "type": "preprint",
  "updated_at": "2026-10-30T12:23:19Z",
  "url": "https://research.draconitic.com/paper/37yx3tce476sw",
  "venue": "arXiv",
  "versions": []
}