{
  "abstract": "We present a previously undetected stellar stream in the halo of the LMC-mass dwarf galaxy NGC 55 (2 Mpc), as part of an ongoing effort to characterize the stellar halos of LMC/SMC-mass dwarfs in the DEEP component of the DECam Local Volume Exploration (DELVE) survey. This structure is aligned with an outflow traced by H$α$ emission, a spur and cloud of neutral hydrogen, and the ultra-diffuse and possibly disrupting satellite galaxy NGC 55-dw1. We investigate possible ex-situ progenitor scenarios for this stream through the local luminosity-metallicity relation and a set of toy dynamical models that include gaseous, stellar, and dark matter components. If the stream is a product of a previous merger, the progenitor galaxy had an absolute magnitude $M_V \\leq -7.2$ and a stellar mass $M_* \\geq 10^5 M_{\\odot}$ based on extrapolations of the detected stellar populations. If it is disrupted material from the ultra-diffuse satellite, their shared progenitor had an absolute magnitude $M_V \\leq -8.3$ and a stellar mass $M_* \\geq 10^{5.2} M_{\\odot}$. We compare our stream and progenitor scenarios to those for NGC 300, a galaxy with a stellar mass similar to that of NGC~55 and known to host multiple structures in its halo. Our results demonstrate that even relatively isolated LMC-mass galaxies can have complex accretion histories, providing new tests of hierarchical galaxy formation at low masses.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.22071",
  "author_total": 35,
  "authors": [
    {
      "name": "Benjamin N. Velguth"
    },
    {
      "name": "Burçin Mutlu-Pakdil"
    },
    {
      "name": "Erik Tollerud"
    },
    {
      "name": "Sarah Pearson"
    },
    {
      "name": "Kristine Spekkens"
    },
    {
      "name": "Amandine Doliva-Dolinsky"
    },
    {
      "name": "Michael G. Jones"
    },
    {
      "name": "Denija Crnojević"
    },
    {
      "name": "Jeffrey L. Carlin"
    },
    {
      "name": "David J. Sand"
    },
    {
      "name": "Paul Bennet"
    },
    {
      "name": "Guy Stringfellow"
    },
    {
      "name": "William Cerny"
    },
    {
      "name": "Alex Drlica-Wagner"
    },
    {
      "name": "Joanna D. Sakowska"
    },
    {
      "name": "Jaclyn Jensen"
    },
    {
      "name": "Laura C. Hunter"
    },
    {
      "name": "Eric F. Bell"
    },
    {
      "name": "David Martínez-Delgado"
    },
    {
      "name": "Anirudh Chiti"
    },
    {
      "name": "Adam Smercina"
    },
    {
      "name": "Nitya Kallivayalil"
    },
    {
      "name": "Deepthi S. Prabhu"
    },
    {
      "name": "Alexander H. Riley"
    },
    {
      "name": "Yumi Choi"
    },
    {
      "name": "Noelia E. D. Noël"
    },
    {
      "name": "Sasha N. Campana"
    },
    {
      "name": "Guinevere Herron"
    },
    {
      "name": "Alistair R. Walker"
    },
    {
      "name": "Andrew B. Pace"
    },
    {
      "name": "Clara E. Martínez-Vázquez"
    },
    {
      "name": "Clecio R. Bom"
    },
    {
      "name": "Julio A. Carballo-Bello"
    },
    {
      "name": "Pol Massana"
    },
    {
      "name": "Gustavo E. Medina"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/09ndt52x3z31z.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.22071",
  "fulltext_url": null,
  "id": "09ndt52x3z31z",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.22071",
  "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",
      "3103|Galaxies: Formation, Evolution, Phenomena"
    ]
  ],
  "openalex": "W7213888673",
  "pdf_url": "https://arxiv.org/pdf/2609.22071",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-18",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/09ndt52x3z31z.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:26:03Z",
      "native_id": "2609.22071",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.22071"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    }
  ],
  "title": "Discovery, Characterization, and Potential Origins of a Stream in the Stellar Halo of Nearby LMC-Mass Galaxy NGC 55",
  "title_text": "Discovery, Characterization, and Potential Origins of a Stream in the Stellar Halo of Nearby LMC-Mass Galaxy NGC 55",
  "type": "preprint",
  "updated_at": "2026-10-30T12:26:03Z",
  "url": "https://research.draconitic.com/paper/09ndt52x3z31z",
  "venue": "arXiv",
  "versions": []
}