研究課題/領域番号 |
22KF0246
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補助金の研究課題番号 |
22F22327 (2022)
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研究種目 |
特別研究員奨励費
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配分区分 | 基金 (2023) 補助金 (2022) |
応募区分 | 外国 |
審査区分 |
小区分16010:天文学関連
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研究機関 | 大阪大学 |
研究代表者 |
井上 芳幸 大阪大学, 大学院理学研究科, 准教授 (70733989)
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研究分担者 |
OWEN ELLIS 大阪大学, 大学院理学研究科, 外国人特別研究員
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研究期間 (年度) |
2023-03-08 – 2025-03-31
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研究課題ステータス |
交付 (2023年度)
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配分額 *注記 |
2,300千円 (直接経費: 2,300千円)
2024年度: 600千円 (直接経費: 600千円)
2023年度: 1,200千円 (直接経費: 1,200千円)
2022年度: 500千円 (直接経費: 500千円)
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キーワード | Cosmic rays / hadronic interactions / magnetic fields / galaxy evolution |
研究開始時の研究の概要 |
物理学における重要課題の一つである宇宙史解明において、銀河の形成・進化過程の理解は必要不可欠である。近年、銀河宇宙線の役割が重要な研究テーマとなっている。特に、銀河は形成進化過程において互いに相互作用を起こすため、孤立銀河だけでなく、銀河集団での宇宙線の役割も理解する必要がある。本研究課題においては、銀河間距離が近い故に銀河間相互作用が強いコンパクト 銀河群における宇宙線の役割を解明する。そして、本成果を銀河進化の枠組み全体へと適応するこ とを目指す。
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研究実績の概要 |
During the first 4 months of the research program, this project led to the publication of 1 paper (Lin, Yang & Owen, 2023), and the submission of 1 further paper (Owen, Han & Wu, submitted to Phys. Rev. D). These concern the development of cosmic ray interactions and the effects of the magnetohydrodynamics (MHD) of diffuse astrophysical structures around galaxies, and cosmic ray propagation microphysics in magnetic fields, respectively. Additionally, 7 oral presentations (4 invited) were delivered in departmental/group seminars and national/international conferences relating to results obtained during the initial stages of this project.
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現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
Focus during this initial stage of the project was placed on resolving the cosmic ray interaction and propagation microphysics in magnetized, multiphase diffuse astrophysical environments, particularly within flows and large-scale structures. Building-up the microphysical picture of cosmic ray physics is an essential foundation before robust macroscopic models can be constructed on galactic scales. The following specific developments have been completed: (1)A large-scale scattering formulation of cosmic ray propagation and interaction has been developed. This was applied to large scale magnetic fields and the propagation of ultrahigh-energy cosmic rays as a demonstration, but the formation is general for inhomogeneous magnetic field structures and will be applied to the science goals of this project. The first demonstration study has been submitted for publication at Physical Review D and is currently undergoing peer review. (2)A microphysical hadronic cosmic ray interaction code has been constructed using state-of-the art interaction cross sections. This allows for a full treatment of spectrally resolved hadronic cosmic rays, self-consistent production of secondary leptonic cosmic rays and a complete treatment of their momentum evolution. This has been implemented in an adaptive mesh refined MHD code (FLASH). Code demonstration and validation runs will soon begin.
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今後の研究の推進方策 |
As of April 2023, the project is progressing to schedule. The immediate technical priorities to be developed during the next stage of the project (FY 2023) are: (1) Development of robust treatment of magnetized cloud flow interaction; development of a multi-phase framework for a galactic flow, properly accounting for the non-thermal driving history and cosmic ray engagement at the cloud/flow boundary. (2) Validation of self-consistent hadronic cosmic ray code model in MHD simulations of galactic bubbles and outflows. First science demonstration case. (3) Compute gamma-ray emission from hadronic processes multi-phase flows and determine its evolutionary progression under different flow driving physics and boundary conditions. (4) Calculation of dust grain properties under cosmic ray collisions. Application to 1-dimensional models of galactic outflows and circum-galactic environments. Application to a simple cosmic ray advection/diffusion model of a galaxy to obtain testable mid-infrared observables for cosmic ray activity in galactic ecosystems. Application of cosmic ray propagation and interaction models to compact galaxy group environments will proceed in FY 2024, after the above microphysical treatments have been developed.
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