{
  "abstract": "The Einstein Telescope (ET), the European next-generation gravitational-wave observatory, is at a decisive stage: the choice of its detector configuration is still open, with profound implications for its scientific output. We provide a quantitative basis for this choice by comparing two candidate configurations at their proposed sites: the triangular design ($Δ$) at the Euregio Meuse-Rhine site, and the 2L design, with interferometers in Sardinia, Italy, and Lusatia, Germany. We present the first realistic estimates of sky-localization uncertainties for binary neutron star (BNS) mergers, moving beyond Fisher-matrix forecasts to full Bayesian parameter estimation that captures the multimodal structure of the sky posterior. We focus mainly on the high-frequency interferometers alone, providing an expected scenario for the first years of ET operations, as the more challenging low-frequency instruments will come online later. BNS injections span different sky positions and luminosity distances between 40 and 2000 Mpc, corresponding to signal-to-noise ratios (SNRs) from 12 to 720. Our analysis relaxes the long-wavelength approximation and includes Earth's rotation and higher-order modes, all of which improve sky localization. We find that the $Δ$ configuration localizes low- and moderate-SNR sources in eight degenerate sky modes spread across both hemispheres and over the day and night sides of the Earth, with 90% credible areas reaching $\\sim 2 \\times 10^4 \\, \\mathrm{deg}^2$. In contrast, the 2L configuration recovers a single dominant mode that contains at least 50% of the posterior probability and is one to two orders of magnitude smaller in area. This represents a substantial advantage for multimessenger follow-up campaigns.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.27081",
  "author_total": 4,
  "authors": [
    {
      "name": "Filippo Santoliquido"
    },
    {
      "name": "Jacopo Tissino"
    },
    {
      "name": "Marica Branchesi"
    },
    {
      "name": "Ulyana Dupletsa"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/6emafhh16tk9m.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.27081",
  "fulltext_url": null,
  "id": "6emafhh16tk9m",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.27081",
  "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.CO"
    ],
    [
      "arxiv",
      "astro-ph.HE"
    ],
    [
      "arxiv",
      "astro-ph.IM"
    ],
    [
      "arxiv",
      "astro-ph.SR"
    ],
    [
      "arxiv",
      "gr-qc"
    ],
    [
      "openalex",
      "3103|Pulsars and Gravitational Waves Research"
    ]
  ],
  "openalex": "W7223092854",
  "pdf_url": "https://arxiv.org/pdf/2610.27081",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-19",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/6emafhh16tk9m.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:34:04Z",
      "native_id": "2610.27081",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.27081"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.HE",
      "subfield": "high-energy-astrophysics"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.IM",
      "subfield": "instrumentation-methods"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.SR",
      "subfield": "stellar"
    },
    {
      "field": "physics",
      "origin": "arxiv:gr-qc",
      "subfield": "gravitation"
    }
  ],
  "title": "Localizing binary neutron stars with the Einstein Telescope: a full Bayesian comparison of the triangular and 2L configurations",
  "title_text": "Localizing binary neutron stars with the Einstein Telescope: a full Bayesian comparison of the triangular and 2L configurations",
  "type": "preprint",
  "updated_at": "2026-10-30T12:34:04Z",
  "url": "https://research.draconitic.com/paper/6emafhh16tk9m",
  "venue": "arXiv",
  "versions": []
}