{
  "abstract": "Born out of the turbulent, dense gas of the early Universe, globular clusters (GCs) represent a significantly different star-formation mode compared to the local Universe. To quantify the initial cluster conditions, we perform the long-term dynamical evolution of GCs using the high-precision direct N-body simulation code PeTar. As the first step in a series of studies, we investigate the two low-mass outer-halo GCs, Eridanus and Whiting 1. By comparing simulated number density profiles with observations, we derive best-fit initial half-mass radii of $2.0 \\pm 1.0$ pc for Eridanus and $2.5 \\pm 0.5$ pc for Whiting 1, corresponding to initial surface densities of $2592.03 M_\\odot pc^{-2}$ and $226.35 M_\\odot pc^{-2}$, respectively -- 2-3 orders of magnitude higher than their present-day values. The absence of multiple populations (MPs) in Whiting 1 and young massive clusters (YMCs), in contrast to the MP-hosting Eridanus, supports the scenario that MP formation requires higher initial surface density and/or lower metallicity. Using the simulations as a template, we identify five high-probability extra-tidal candidates of Whiting 1 from Gaia DR3 and APOGEE DR17, which exhibit coherent kinematics and chemical abundances. Our results demonstrate that the diffuse states of low-mass GCs are the product of long-term dynamical expansion and tidal stripping, and that their primordial configurations were significantly denser.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2611.06648",
  "author_total": 8,
  "authors": [
    {
      "name": "Ruoyun Huang"
    },
    {
      "name": "Baitian Tang"
    },
    {
      "name": "Long Wang"
    },
    {
      "name": "Holger Baumgardt"
    },
    {
      "name": "Xia Li"
    },
    {
      "name": "Genhao Liu"
    },
    {
      "name": "Jundan Nie"
    },
    {
      "name": "Hao Tian"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/b1vek1q2cb1m3.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2611.06648",
  "fulltext_url": null,
  "id": "b1vek1q2cb1m3",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2611.06648",
  "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/2611.06648",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-04",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/b1vek1q2cb1m3.ris",
  "sources": [
    {
      "first_seen": "2026-11-05T15:20:56Z",
      "native_id": "2611.06648",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2611.06648"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    }
  ],
  "title": "Investigating the initial conditions of globular clusters via $N$-body simulations: I. half-mass radius and stellar density",
  "title_text": "Investigating the initial conditions of globular clusters via N-body simulations: I. half-mass radius and stellar density",
  "type": "preprint",
  "updated_at": "2026-11-09T00:20:20Z",
  "url": "https://research.draconitic.com/paper/b1vek1q2cb1m3",
  "venue": "arXiv",
  "versions": []
}