{
  "abstract": "This study introduces GraphShed, a data-derived group-finder that applies top-down watershed segmentation to Voronoi-induced graphs, identifying galaxy systems directly from the density field via a GraphShed-derived linking length, with no density thresholds or tunable parameters. A GraphShed galaxy group catalog compared to a friends-of-friends (FoF) catalog is built from the IllustrisTNG100-1 simulation with a box size of ∼75 Mpc h ⁻¹ yielding 1067 and 987 systems, respectively. The GraphShed-derived linking length adapts to the global clustering power of the sample, varying by ∼18% relative to FoF across different sample selections; thus, catalog differences originate in the watershed segmentation. A cross-catalog comparison shows that ∼58% of FoF systems are identically reproduced by GraphShed, ∼5% are completely removed, and the remainder are partially shaved and/or split into multiple systems. While the M ₂₀₀ distributions of the two catalogs are statistically consistent, other structural properties including, R ₂₀₀ , sphericity, compactness, spin, and centroid shift, differ significantly in at least some richness ranges. The unweighted two-point correlation function of GraphShed systems exhibits a higher amplitude on small scales, r ≲ 1 Mpc h ⁻¹ and agrees with FoF for r ≳ 5 Mpc h ⁻¹ . A velocity-based classification reveals that GraphShed resolves more interacting pairs than FoF, demonstrating its ability to distinguish nearby overdense structures that position-only methods merge into single systems. These results demonstrate that GraphShed preserves cosmological statistics while providing a more resolved detection of galaxy systems and their dynamical interactions.",
  "abstract_shown": true,
  "affiliations": [
    "Shahid Beheshti University",
    "Institute for Research in Fundamental Sciences (IPM)",
    "The University of Lahore"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 4,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "P. Ghafour",
      "orcid": "0009-0003-2960-1563"
    },
    {
      "affs": [
        1
      ],
      "name": "S. Ansarifard",
      "orcid": "0000-0002-3655-5417"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "M. H. Jalali Kanafi",
      "orcid": "0009-0000-4905-7209"
    },
    {
      "affs": [
        0,
        1,
        2
      ],
      "name": "S. M. S. Movahed",
      "orcid": "0000-0001-7897-484X"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/d09wft349qkae.bib",
  "cited_by": 0,
  "doi": "10.3847/1538-4357/aea8fa",
  "fulltext_url": null,
  "id": "d09wft349qkae",
  "issns": [
    "1538-4357",
    "0004-637X"
  ],
  "landing_url": "https://iopscience.iop.org/article/10.3847/1538-4357/aea8fa",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "feed-journal",
      "astronomy/general"
    ],
    [
      "openalex",
      "3103|Galaxies: Formation, Evolution, Phenomena"
    ]
  ],
  "openalex": "W7163332281",
  "pdf_url": "https://iopscience.iop.org/article/10.3847/1538-4357/aea8fa/pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-27",
  "publisher": "American Astronomical Society",
  "ris": "https://research.draconitic.com/paper/d09wft349qkae.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:17Z",
      "native_id": "10.3847/1538-4357/aea8fa",
      "source": "feed-iop",
      "url": "https://iopscience.iop.org/article/10.3847/1538-4357/aea8fa"
    },
    {
      "first_seen": "2026-10-30T12:18:11Z",
      "native_id": "10.3847/1538-4357/aea8fa",
      "source": "crossref",
      "url": "https://iopscience.iop.org/article/10.3847/1538-4357/aea8fa"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "openalex:3103|Galaxies: Formation, Evolution, Phenomena",
      "subfield": "galaxies"
    }
  ],
  "title": "GraphShed: A Data-derived Graph-based Watershed Group-finder",
  "title_text": "GraphShed: A Data-derived Graph-based Watershed Group-finder",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:11Z",
  "url": "https://research.draconitic.com/paper/d09wft349qkae",
  "venue": "The Astrophysical Journal",
  "versions": []
}