{
  "abstract": "Models of bursty star formation in low-mass (10^8-10^9.5 Msun) galaxies at z>4 differ most in the suppressed phases: what drives the decline, how fast star formation falls, and how long it stays low. OASIS Paper I showed that such quiet galaxies are common and old; here we measure how they got there and how their ionized gas responds. We compare Balmer-line star-formation rates (SFRs) with 100-Myr averages from the stellar continuum, in NIRSpec/PRISM spectra of 54 OASIS galaxies at z>4, including three mini-quenched galaxies below the quenching threshold and five lulling galaxies at least 0.6 dex below the star-forming main sequence (SFMS) but still star-forming. Galaxies above the SFMS rise and fade equally often, whereas those below it are mostly fading: the lulling galaxies formed little more than a tenth of their mass in the last 100 Myr, and their decline began tens to ~100 Myr before observation. Suppressed phases thus last of order 100 Myr, as long as or longer than in most simulations, whereas recovery is much faster: few galaxies below the SFMS are rising. The ionized gas tracks these changes in star formation. [OIII]/[OII] falls from galaxies above the SFMS to the lulling ones, even at fixed mass and after dust correction, and follows the recent change in SFR (SFR_10/SFR_100) more closely than the position relative to the SFMS: two rising galaxies below the SFMS are highly ionized. This is expected if fewer and softer ionizing photons than in strongly star-forming galaxies meet gas depleted by earlier star formation. Lulling galaxies show ISM conditions distinct from those of strongly star-forming galaxies. The declines are faster than passive gas exhaustion predicts, favoring feedback that expels the gas or keeps it from forming stars. Quiet phases are thus long, feedback-driven episodes, and the ionized gas traces where a galaxy is in its burst cycle.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.41490",
  "author_total": 22,
  "authors": [
    {
      "name": "Tobias J. Looser"
    },
    {
      "name": "Francesco D'Eugenio"
    },
    {
      "name": "William M. Baker"
    },
    {
      "name": "Santiago Arribas"
    },
    {
      "name": "Andrew J. Bunker"
    },
    {
      "name": "Stefano Carniani"
    },
    {
      "name": "Stéphane Charlot"
    },
    {
      "name": "Jacopo Chevallard"
    },
    {
      "name": "Mirko Curti"
    },
    {
      "name": "Qiao Duan"
    },
    {
      "name": "Kevin Hainline"
    },
    {
      "name": "Jakob M. Helton"
    },
    {
      "name": "Yuki Isobe"
    },
    {
      "name": "Benjamin D. Johnson"
    },
    {
      "name": "Pierluigi Rinaldi"
    },
    {
      "name": "Brant Robertson"
    },
    {
      "name": "Fengwu Sun"
    },
    {
      "name": "Sandro Tacchella"
    },
    {
      "name": "James A. A. Trussler"
    },
    {
      "name": "Hannah Übler"
    },
    {
      "name": "Joris Witstok"
    },
    {
      "name": "Zihao Wu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/9x5gkq8amvymd.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.41490",
  "fulltext_url": null,
  "id": "9x5gkq8amvymd",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.41490",
  "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.GA"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2610.41490",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-30",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/9x5gkq8amvymd.ris",
  "sources": [
    {
      "first_seen": "2026-11-02T12:21:15Z",
      "native_id": "2610.41490",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.41490"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    }
  ],
  "title": "OASIS II: The Ionized Gas Traces Feedback-Driven Declines into the Quiet Side of Bursty Star Formation at z > 4",
  "title_text": "OASIS II: The Ionized Gas Traces Feedback-Driven Declines into the Quiet Side of Bursty Star Formation at z > 4",
  "type": "preprint",
  "updated_at": "2026-11-04T15:20:51Z",
  "url": "https://research.draconitic.com/paper/9x5gkq8amvymd",
  "venue": "arXiv",
  "versions": []
}