{
  "abstract": "Supernova remnants (SNRs) are widely considered to be the primary accelerators of Galactic cosmic rays. In recent years, detailed observations have significantly progressed for young SNRs interacting with molecular clouds, a prime example being RX J1713.7−3946. When molecular clouds are clumpy, their impact can affect not only radiation properties but also shock-wave propagation. Therefore, a quantitative understanding linking observational quantities with the ambient medium structure is highly required. In this study, we perform three-dimensional hydrodynamic simulations to model a molecular cloud with an inhomogeneous density structure driven by supersonic turbulence and subsequent SNR formation. To investigate various presupernova environments, we systematically vary the medium clumpiness by replacing gas below a threshold number density with a low-density hot gas, quantifying the relationship between the forward shock velocity and the volume filling factor of the high-density clumps. As a result, we find that at an elapsed time of 1000 yr—a typical age for a young SNR—the forward shock can evolve consistently with the fast shock velocity measured in RX J1713.7−3946, provided that the clump volume filling factor is approximately 10% or less. Considering that hadronic gamma-ray emission originates exclusively from the clumpy, high-density gas, our findings suggest that the total energy of cosmic-ray protons in RX J1713.7−3946 is higher than previously estimated, amounting to at least a few percent of the typical supernova explosion energy.",
  "abstract_shown": true,
  "affiliations": [
    "Konan University"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 2,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Kenta Tatsumi"
    },
    {
      "affs": [
        0
      ],
      "name": "Tsuyoshi Inoue",
      "orcid": "0000-0002-7935-8771"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/9f382yctg163b.bib",
  "cited_by": 0,
  "doi": "10.3847/1538-4357/aeae29",
  "fulltext_url": null,
  "id": "9f382yctg163b",
  "issns": [
    "1538-4357",
    "0004-637X"
  ],
  "landing_url": "https://iopscience.iop.org/article/10.3847/1538-4357/aeae29",
  "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": null,
  "pdf_url": "https://iopscience.iop.org/article/10.3847/1538-4357/aeae29/pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-30",
  "publisher": "American Astronomical Society",
  "ris": "https://research.draconitic.com/paper/9f382yctg163b.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:17Z",
      "native_id": "10.3847/1538-4357/aeae29",
      "source": "feed-iop",
      "url": "https://iopscience.iop.org/article/10.3847/1538-4357/aeae29"
    },
    {
      "first_seen": "2026-10-30T12:18:11Z",
      "native_id": "10.3847/1538-4357/aeae29",
      "source": "crossref",
      "url": "https://iopscience.iop.org/article/10.3847/1538-4357/aeae29"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "journal-openalex:3103|Stellar, planetary, and galactic studies",
      "subfield": "stellar"
    }
  ],
  "title": "Impact of Upstream Clumpiness on Supernova Remnant Forward Shock Evolution in Molecular Cloud Environments",
  "title_text": "Impact of Upstream Clumpiness on Supernova Remnant Forward Shock Evolution in Molecular Cloud Environments",
  "type": "peer-reviewed",
  "updated_at": "2026-11-01T00:20:38Z",
  "url": "https://research.draconitic.com/paper/9f382yctg163b",
  "venue": "The Astrophysical Journal",
  "versions": []
}