{
  "abstract": "Baryonic feedback remains one of the primary uncertainties in galaxy formation models because of its impact on the interstellar medium (ISM) and star formation. We investigate its effect on the H$α$ luminosity function (LF) using the Illustris and IllustrisTNG simulations, incorporating direction-dependent dust attenuation and a physically motivated treatment of the propagation of Lyman-series photons. We model three sources of H$α$ emission: star-forming H II regions, collisional excitation and recombination in the diffuse ISM, and AGN-induced photo-excitation of diffuse gas. The models are calibrated against observed H$α$ LFs at $z\\sim 1-1.5$ using a single free parameter relating the star formation rate to the H II-region H$α$ luminosity. We find that emission from diffuse gas contributes $\\sim 1\\%-10\\%$ of the total H$α$ luminosity in both simulation sets. AGN photo-excitation produces only a modest enhancement of the bright end of the LF, although it dominates the H$α$ emission of Illustris galaxies with $L_{\\text{H}α}\\gtrsim 3\\times10^{42}\\ \\rm{erg \\ s^{-1}}$. The low-feedback IllustrisTNG simulations provide good agreement with the observed LFs for all emission models considered, whereas the high-feedback Illustris simulation fails to simultaneously reproduce the faint and bright ends of the LF at $z\\sim 1$. This tension between H$α$ LFs and stacked kSZ measurements highlights the combined power of these probes for constraining the interplay between baryonic feedback, gas properties, and the physics governing emission-line galaxies.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2608.30698",
  "author_total": 4,
  "authors": [
    {
      "name": "Ivan Rapoport"
    },
    {
      "name": "Vincent Desjacques"
    },
    {
      "name": "Ehud Behar"
    },
    {
      "name": "Shmuel Bialy"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/3qdbsjawhky31.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2608.30698",
  "fulltext_url": null,
  "id": "3qdbsjawhky31",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2608.30698",
  "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",
      "3103|Galaxies: Formation, Evolution, Phenomena"
    ]
  ],
  "openalex": "W7204871534",
  "pdf_url": "https://arxiv.org/pdf/2608.30698",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-31",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/3qdbsjawhky31.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:41Z",
      "native_id": "2608.30698",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2608.30698"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    }
  ],
  "title": "Constraining Baryonic Feedback at $z\\sim 1$ with the H$α$ Luminosity Function",
  "title_text": "Constraining Baryonic Feedback at z∼ 1 with the Hα Luminosity Function",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:41Z",
  "url": "https://research.draconitic.com/paper/3qdbsjawhky31",
  "venue": "arXiv",
  "versions": []
}