保健衛生学部 リハビリテーション学科
Profile Information
- Affiliation
- School of Medicine Faculty of Medicine, Fujita Health University
- Degree
- 博士(理学)(名古屋大学)
- J-GLOBAL ID
- 200901003971539256
- researchmap Member ID
- 6000001840
Research Interests
8Research Areas
4Research History
1Education
1Papers
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Astronomy & Astrophysics, Jun 22, 2026 Peer-reviewedThe intracluster medium (ICM) is rich in chemical elements, produced by core-collapse (SNcc) and Type Ia supernovae (SNIa) over the last ∼12 Gyr. While cluster outskirts are uniformly enriched with Fe at ∼0.3 solar, strongly suggesting that the gas had been pre-enriched during or before the assembly of galaxies into clusters, the Fe abundance is known to centrally increase in the core of relaxed clusters. The origin of these central Fe peaks however, as well as the apparent presence of mysterious drops previously reported in the very centre of a number of systems, remain to be clarified.In this paper, we address these two questions by measuring the spatial distribution of Fe and its relative Si/Fe, S/Fe, Ar/Fe, Ca/Fe, Cr/Fe, Mn/Fe, and Ni/Fe ratios in the X-ray bright, nearby Perseus cluster.We take advantage of the unprecedented spectral resolution (∼5 eV) offered by the Resolve microcalorimeter on board which observed four distinct pointings of Perseus out to ∼250 kpc (∼0.2r_500) during its performance verification phase.Although the presence of an X-ray bright AGN challenges a precise quantification of absolute abundances in the very core, our baseline analysis rules out a strong drop with $>2σ$ confidence, at variance with previous charge-coupled device (CCD) measurements. In addition, we find a remarkable spatial uniformity of X/Fe ratios, supporting the idea of negligible late SNIa enrichment from the brightest cluster galaxy NGC,1275. We also compare the overall chemical composition of the Perseus ICM with SNcc and SNIa nucleosynthesis yield models, finding that the co-existence of two separate SNIa enrichment channels is not needed to reproduce the ICM ratios satisfactorily.
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The Astrophysical Journal, 1003(2) 156-156, May 22, 2026 Peer-reviewedAbstract The supermassive binary system, η Carinae, is experiencing enormous wind-driven mass loss at a rate unparalleled in the rest of the Galaxy. Their wind–wind collision (WWC) continuously produces shock heated, X-ray-emitting plasmas. The XRISM X-ray observatory observed the system in 2023 and 2024 when the X-ray emission began to increase toward periastron passage in 2025. This paper reports unprecedentedly high-resolution X-ray spectra in the Fe K α band between 6.2 and 7.1 keV, obtained with the Resolve X-ray microcalorimeter. The hydrogen-like (Ly α ) and helium-like (He α ) lines reveal three velocity components. Two of them are broadened with maximum velocities of 2000–3000 km s −1 , likely originating from the postshock companion wind. The other is relatively narrow, with a Gaussian broadening of only ∼290 km s −1 in 1 σ , which may originate from the postshock companion wind at the WWC stagnation point or penetrating the primary wind. The Fe fluorescent lines exhibit a moderate blueshift and broadening with velocities at 100–200 km s −1 , consistent with the primary wind’s velocity field. The spectra also confirm a Compton shoulder of the He α line complex for the first time. Both fluorescing and scattering spectral profiles indicate that the binary system is seen from the companion side during these observations. The flux ratio of the Compton-scattering emission to the fluorescent line suggests substantial hydrogen depletion of the primary wind, expected from CNO-cycled hydrogen nuclear fusion gas.
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Nature Astronomy, 10(6) 880-891, Mar 31, 2026 Peer-reviewed
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Nature, 651(8107) 909-913, Mar 25, 2026 Peer-reviewed
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The Astrophysical Journal, 998(2) 210-210, Feb 11, 2026 Peer-reviewedAbstract The XRISM/Resolve microcalorimeter directly measured the gas velocities in the core of the Virgo Cluster, the closest example of active galactic nucleus (AGN) feedback in a cluster. This proximity allows us to resolve the kinematic impact of feedback on scales down to 5 kpc. Our spectral analysis reveals a high velocity dispersion of km s −1 near the AGN, which steeply declines to ∼60 km s −1 between 5 and 25 kpc in the northwest direction. The observed line-of-sight bulk velocity in all regions is broadly consistent with the central galaxy, M87, with a mild trend toward blueshifted motions at larger radii. Systematic uncertainties have been carefully assessed and do not affect the measurements. The central velocities, if attributed entirely to isotropic turbulence, correspond to a transonic intracluster medium at sub-6 kpc scales with 3D Mach number and a nonthermal pressure fraction of . Simple models of weak shocks and sound waves and calculations assuming isotropic turbulence both support the hypothesis that the velocity field reflects a mix of shock-driven expansion and turbulence. Compared to other clusters observed by XRISM to date, M87’s central region stands out as the most kinematically disturbed, exhibiting both the highest velocity dispersion and the largest 3D Mach number, concentrated at the smallest physical scales.
Misc.
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大気球シンポジウム: 2020年度 = Balloon Symposium: 2020, Nov, 2020大気球シンポジウム 2020年度(2020年11月5-6日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)), 相模原市, 神奈川県 Balloon Symposium 2020 (November 5-6, 2020. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS)), Sagamihara, Kanagawa Japan 著者人数: 67名 資料番号: SA6000151012 レポート番号: isas20-sbs-012
Presentations
61-
大気球シンポジウム: 2024年度, Oct, 2024, 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS)レポート番号: isas24-sbs-008
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日本物理学会講演概要集(CD-ROM), 2024
Teaching Experience
1-
物理学 (藤田保健衛生大学)
Professional Memberships
1Research Projects
2-
Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, Apr, 2023 - Mar, 2027
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Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, Apr, 2018 - Mar, 2022