{
  "abstract": "Galaxy morphology is a fundamental tracer of galaxy assembly, but its characterization becomes increasingly uncertain in the early Universe. We investigate morphological classifications across different methodologies over the redshift range $0.6 < z < 8.0$, using JWST observations of 15,567 galaxies with 6,099 synthetic galaxies from IllustrisTNG. To quantify morphology without relying on visual labels or prescribed light profiles, we use an unsupervised-supervised hybrid machine-learning approach based on the non-parametric MEGG system, which combines the second moment of the light distribution, Entropy, Gini, and Gradient Pattern Analysis. We find that parametric and non-parametric classifications remain broadly consistent at $z < 2.5$, but diverge systematically at higher redshift. We identify this epoch as the Morphological Indeterminacy Regime (MIR), in which classical disc and spheroidal categories no longer provide a unique description of the galaxy population. The fraction of mixed-interpretation galaxies increases with redshift, reaching $F_{\\rm MIR} \\sim 0.55$ at $z > 2.5$. Cross-domain and projection-invariance tests show that the classifications are stable and insensitive to data set and viewing angle. In the interval $2.5 < z < 8.0$, MIR galaxies occupy an intermediate stellar-mass regime (median; $\\log(M_\\star/M_\\odot) \\sim 9.7$), between low-mass discs (median; $\\log(M_\\star/M_\\odot) \\sim 9.5$) and massive spheroids (median; $\\log(M_\\star/M_\\odot) \\sim 10.1$), while irregular systems have stellar-mass distributions similar to those of MIR galaxies. We interpret these results as evidence that morphological indeterminacy is a characteristic feature of galaxy assembly in the early Universe, reflecting a population of dynamically young systems that have not yet settled into the classical Hubble sequence.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.24078",
  "author_total": 6,
  "authors": [
    {
      "name": "Igor Kolesnikov"
    },
    {
      "name": "Reinaldo Ramos de Carvalho"
    },
    {
      "name": "Jeong Hwan Lee"
    },
    {
      "name": "Rodrigo Flores-Freitas"
    },
    {
      "name": "Vitor M. Sampaio"
    },
    {
      "name": "Luiz A. Silva-Lima"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/8yvjsqvxcz8rz.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.24078",
  "fulltext_url": null,
  "id": "8yvjsqvxcz8rz",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.24078",
  "language": null,
  "licence": "CC-BY-NC-ND-4.0",
  "licence_label": "CC BY-NC-ND 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.GA"
    ],
    [
      "openalex",
      "3103|Galaxies: Formation, Evolution, Phenomena"
    ]
  ],
  "openalex": "W7223065452",
  "pdf_url": "https://arxiv.org/pdf/2610.24078",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-20",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/8yvjsqvxcz8rz.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:34:04Z",
      "native_id": "2610.24078",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.24078"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    }
  ],
  "title": "Beyond the Disc--Spheroid Dichotomy at $0.6 < z < 8.0$: Evidence for a Morphological Indeterminacy Regime from JWST",
  "title_text": "Beyond the Disc--Spheroid Dichotomy at 0.6 < z < 8.0: Evidence for a Morphological Indeterminacy Regime from JWST",
  "type": "preprint",
  "updated_at": "2026-11-09T00:20:16Z",
  "url": "https://research.draconitic.com/paper/8yvjsqvxcz8rz",
  "venue": "arXiv",
  "versions": []
}