超新星は宇宙の巨大粒子加速器か －可視光とニュートリノで探るペバトロン候補－

2026-07-21 理化学研究所

超新星 SN 2023uqf方向から南極のIceCubeへ高エネルギーニュートリノが到来

＜関連情報＞

• https://www.riken.jp/press/2026/20260721_1/index.html
• https://iopscience.iop.org/article/10.3847/2041-8213/ae80bd

相互作用駆動型Ibn超新星は一時的なPeVatron候補となるか：SN 2023uqfの事例 Interaction-powered Type Ibn Supernovae as a Transient PeVatron Candidate: The Case of SN 2023uqf

Ryo Sawada, Yusuke Inoue, and Yosuke Ashida
The Astrophysical Journal Letters  Published: 2026 July 8
DOI:10.3847/2041-8213/ae80bd

Abstract

We investigate whether the Type Ibn supernova SN 2023uqf, reported close in time and direction to the ∼442 TeV IceCube alert IC-231004A, is physically consistent with a shock–circumstellar medium (CSM) interaction scenario. One-dimensional radiation-hydrodynamic calculations with STELLA reproduce the Zwicky Transient Facility (ZTF) optical light curves with a dense, helium-rich CSM following ρ_CSM ∝ r⁻³ and CSM density parameter D’≈ 50. Using the shock evolution and CSM conditions obtained from the optical-fit radiation-hydrodynamic model, we model time-dependent cosmic-ray acceleration and hadronic neutrino production during the interaction phase. In our fiducial model, the inferred shock and CSM properties open a short-lived window in which multi-PeV hadron acceleration and efficient hadronic interactions can coexist. Additional loss-limited effects could reduce the high-energy cutoff, but the model provides a useful optical-to-neutrino consistency test for a transient PeVatron-like phase. After folding the predicted neutrino emission through the IceCube effective area, we obtain an expected number of ∼10⁻⁵–10⁻⁴ track-like events at d = 723 Mpc, depending on the alert selection. In the low-count regime, the model predicts a detection-time weighting for a rare event, and the detection time of IC-231004A falls within the high-weight interval, while its energy scale is compatible with the modeled spectrum. Although a single event cannot establish a definitive association, our results show that the optically inferred environment of SN 2023uqf can satisfy the basic timing and energy requirements for a transient PeVatron-like phase in the fiducial model and illustrate how interaction-powered Type Ibn supernovae can be tested as high-energy neutrino sources.