超高速計算機(スーパーコンピューター・重力専用計算機)による数値的天文学の構築

1992 年度 実績報告書

• 研究課題/領域番号: 02302014
• 研究機関: 国立天文台
• 研究代表者: 観山 正見 国立天文台, 理論天文学研究系, 教授 (00166191)
• 研究分担者: 藤本 光昭 名古屋大学, 理学部, 教授 (70022580) ; 土佐 誠 東北大学, 理学部, 教授 (50022728) ; 中沢 清 東京工業大学, 理学部, 教授 (10025455) ; 佐藤 勝彦 東京大学, 理学部, 教授 (00111914) ; 内田 豊 東京大学, 理学部, 教授 (90012814)
• キーワード: 数値シミュレーション / スーパーコンピューター / 専用計算機 / 重力多体系 / 数値的天文学 / 流体力学計算 / 磁気流体力学計算 / 数値的相対論

研究概要

天体現象においては、自己重力が本質的に係わる場合が多く、このため現象は非線形・非平衡でありかつ非一様となる場合が多々あり問題の解析を複雑にしている。従ってこれらの現象の解析には、超高速計算機を用いたシミュレーションが有効な手段となり得る。特に最近のスーパーコンピューターの演算速度や記憶容量の飛躍的発展によって、以前は不可能であった問題が解析可能となってきている。そこで、それら超高速計算機の能力を十分生かして、かつ天体物理に本質的な重力の効果を考慮したソフトウェアーの開発が必要である。一方球状星団のような重力多体系の問題のように重力の計算部分は極めて簡単な表式であるため専用計算機を設計・製作した方が良い場合もある。
そこで、個々の天体現象をシミュレーションによって解析し、発見法的に基本法則の求めたり、観測天文学に於いての現象論となり得る様な数値的天文学の構築のために、その基礎となる計算法や専用マシンの設計を確立する事が本申請研究の目的であった。
最終年度に当たるので、2年度にわたる諸成果を総合的に討議するため、全体の研究会を開催した。そこで残された問題点を検討するとともに、新たな数値天文学のあり方を探った。研究会には、多くの研究者が参加し、成果発表と共に活発な意見交換がなされた。
3年間の研究論文を集めて論文集を作成した。
宇宙現象に於いて、それぞれの分野の特殊性と普遍性を導く事によって、それぞれの問題に最適な数値手法を開発し、あるいは専用計算機を作成して、発見法的に法則性を導き現象論の構築を目指すことが前進した。

研究成果

• [文献書誌] Inutsuka,S.: "Self-Similar Solutions and the Stability of Collapsing Isothermal Filaments" Astrophysical Journal. 388. 392-399 (1992)
• [文献書誌] Watanabe,S.: "Collision and Tidal Interaction Between Planetesimals" Astrophysical Journal. 391. 318-335 (1992)
• [文献書誌] Miyama,S.M.: "Criteria for Collapse and Fragmentation of Rotating Clouds" Publications of Astronomical Society of Japan. 44. 193-202 (1992)
• [文献書誌] Kumai,Y.: "Metalicity and Gas Mass Fraction in Irregulars and Blue Compact Galaxies," Astron.Astrophys.257. 511-514 (1992)
• [文献書誌] Ohtsuki,K.: "Planetary Accretion in the Solar Gravitational Field" ¨Protostars and Planets III¨ed.Black,D.D.and Mtthews,M.,Univ.Arisona press. (1992)
• [文献書誌] 藤本 光昭: "銀河と宇宙の磁場" 日本物理学会誌. 47. 624-631 (1992)
• [文献書誌] Sawada,K.: "Three-Dimensional Hydrodynamic Simulation of an Accretion Flow in a Close Binary System" Mon.Not.R.astr.Soc.255. 17-20 (1992)
• [文献書誌] Matsuda,T.: "Numerical Simulations of Two-Dimensional and Three-Dimensional Accretion Flows" Mon.Not.R.astr.SoC.255. 183-191 (1992)
• [文献書誌] Chakrabarti,S.K.: "Spiral Shocks and Subday Variability in SS433" Astrophys.J.390. 639-644 (1992)
• [文献書誌] Matsuda,T: "Hydrodynamics of Wind Accretion in Astrophysics" Computational Fluid Dyamics JOURNAL. 1. 115-127 (1992)
• [文献書誌] Kiguchi,M.: "Rrimordial Solar Nebula Embeded in Corona" Science and Technology. 4. 87-93 (1992)
• [文献書誌] Inagaki,S.: "Gravitational Clustering of Galaxies:Comparison between Thermodynamic Theory and N-Body Simulations:III.Velocity Distributions for Different Mass Components." Astrophys.J.386. 9-18 (1992)
• [文献書誌] Lahav,O.: "Non-Gausssian Signatures from Gaussian Initial Fluctiations:Evolution of Skewness and Kurtosis in Cosmological Simulations." Astrophys.J.402. 387-397 (1992)
• [文献書誌] Takahashi,K.: "Application of the Generalized Variational principle to Self-Similar Solutions for the Evolution of Star Clusters" Publ.Astron.Soc.Japan. 44. 623-631 (1992)
• [文献書誌] Gouda,N.: "Surviving Cosmologocal models After the Discovery of the Large-Angle Anisotropies of the Cosmic Microwave Background" Astrophys.J.Letters. 395. L59-L63 (1992)
• [文献書誌] Yamashiro,T.: "Origin of Core-Halo Structure in One-Dimensional Self-Garvitating System" Prog.Theor.Phys.88. 269-282 (1992)
• [文献書誌] Sugiyama,N.: "Perturbations of the Cosmic Microwave Backgrornd Radiation and Structure Formations" Prog.Theor.Phys.88. 803-844 (1992)
• [文献書誌] Nozawa,S.: "Emergence of Magnetic Flux from the Convection Zone into the Solar Atmosphere,I.Linear and Nonlinear Adiabatic Evolution of the Convectivi-Parker Instability." Astrophys.J.Suppl.78. 267-282 (1992)
• [文献書誌] Tajima,T.: "On the Origin of Cosmological Magnetic Fields" Astrophys.J.390. 309-321 (1992)
• [文献書誌] Shibata,K.: "Magnetic Reconnection Associated with Emerging Magnetic Flux" Publ.Astr.Soc.Japan. 44. 265-272 (1992)
• [文献書誌] Matsumoto,R.: "Three Dimensional MHD Simulation of the Parker Instability in Galactic Gas Disks and Solar Atmosphere" Publ.Astr.Soc.Japan. 44. 167-175 (1992)
• [文献書誌] Hanawa,T.: "Giant Molecular Cloud Formation through the Parker Instability in a Skewed Magnetic Field" Astrophys.J.Lett.L71-L74 (1992)
• [文献書誌] Bodo,G.: "Non-linear Evolution of Synchrotron Thermal Instabilities" Astron.Astrophys.256. 689-700 (1992)
• [文献書誌] Kawai,G.: "Comparison Between H α and Yohkoh Soft X-ray Images of Emerging Flux Regions" Publ.Astr.Soc.Japan Letters. 44. L193-L198 (1992)
• [文献書誌] Shibata,K.: "Observations of X-ray Jets with the Yohkh Soft X-ray Telescope" Publ.Astr.Soc.Japan Letters. 44. L173-L179 (1992)
• [文献書誌] Sakurai,T.: "Flare-Related Relaxation of Magnetic Shear as Observed with the Soft X-ray Telescope of Yohkoh and with Vector Magnetographs" Publ.Astr.Soc.Japan Letters. 44. L123-L127 (1992)
• [文献書誌] McAllister,A.: "The Structure of the Coronal Soft X-ray Source Associated with the Dark Filament Disappearance of Septermber 28,1991 Using the Yohkoh Soft X-ray Telescope" Publ.Astr.Soc.Japan Letters. 44. L205-L210 (1992)
• [文献書誌] Shibata,K.: "A Unified Model of the MHD Activity in the Galactic CCenter" Proc.of Frontiers of X-ray Astronomy.eds.Y.Tanaka and K.Koyama,Univ.of Academy Press. 419-420 (1992)
• [文献書誌] Watanabe,K.: "On Distances and the Hubble Parameter Determination in Gravitational Lenses" Astrophys.J.394. 38-50 (1992)
• [文献書誌] Tomita,K.: "Density Perturbations Driven by the Irregular Spatial Curvature in Inhomogeneous Cosmological Models" Astrophys.J.394. 401-408 (1992)
• [文献書誌] Tomita,K.: "Masking Effect on High-Redshift QSOs due to Foreground Galaxies" Publ.Astron.Soc.Japan. 45. (1992)
• [文献書誌] Ishikawa,S.: "Asymmetric Explosion in SN1987A" Astron.Astrophys.258. 415-422 (1992)
• [文献書誌] Habe,A.: "Gravitational instavility induced by a cloud cloud collision:The case of head on collision between clouds with different sizes and densities" Publ.Astron.Soc.Japan. 44. 203-226 (1992)
• [文献書誌] Yoshida,R.: "Effect of Deceleration on the gravitational instability of shocked gas layers" Prog.Theor.Phys.88. 251-268 (1992)
• [文献書誌] Sofue,Y.: "Formation of galactic bulges by starbursts and the origin of Hubble Morphological types" Publ.Astron.Soc.Japan. 44. 325-330 (1992)
• [文献書誌] Christodoulou,D.M.: "Dynamical evolution of highly inclined rings" Astrophys.J.395. 113-118 (1992)
• [文献書誌] Wada,K.: "Rapid gas supply to a unclear region in a weak barred potential by self-gravitational instability" Mon.Not.Roy.astron.Soc.258. 82-95 (1992)
• [文献書誌] Shigeyama,T.: "Possible Models for the Type Ia Supernova 1990N" Astrophysical Journal Letters. 386. L13-L16 (1992)
• [文献書誌] Hachisu,I.: "Mixing in Ejecta of Supernovae.I.General Properties of 2-D Rayleigh-Taylor Instabilities and Mixing Width in Ejecta of Supernovae" Astrophysical Journal. 390. 230-252 (1992)
• [文献書誌] Eriguchi,Y.: "The Ring around SN 1987A and Rotation of the Progenitor" Astrophysical Journal. 392. 243-248 (1992)
• [文献書誌] Yamaoka,H.: "Late Detonation Models for the Type Ia Supernovae 1991T and 1990N" Astrophysical Journal Letters. 393. L55-L58 (1992)
• [文献書誌] van den Hervel,E.P.J.: "Accreting White Dwarf Models for CAL 83,CAL 87 and Other Ultrasoft X-Ray Sources in the LMC" Astronomy and AstrophySics. 262. 97-105 (1992)
• [文献書誌] Nomoto,K.: "Type I Supernovae:Theory and Interpretation" The Astronomy and Astrophysics Encyclopedia ed.S.P.Maran (Van Nostrand Reinhold). 890-892 (192)
• [文献書誌] Nomoto,K.: "Nucleosynthesis in Type Ib/Ic Supernovae and Chemical Evolution of Galaxies" Elements and the Cosmos,eds.M.G.Edmunds and R.J.Terlevich (Cambridge University Press). 55-67 (1992)
• [文献書誌] Thielemann,F.-K.: "Type II Supernova Nucleosynthesis as a Function of Progenitor Masses" Elemints and the Cosmos,eds.M.G.Emunds and R.J.Terlevich(Cambridge University Press). 68-77 (1992)
• [文献書誌] Nomoto,K.: "Accretion-Induced Collapse of White Dwarfs" X-Ray Binaries and the Formation of Binary and Millisecond Radio Pulsars,E.P.J.van den Heuvel and S.A.Rappaport(eds.)(NATO ARW,Kluwer),. 189-205 (1992)
• [文献書誌] Nozawa,S.: "Emergence of Magnetic Flux from the Convection Zone into the Solar Atmosphere.I.Linear and Non-linear Adiabatic Evolution of the Convective-Parker Instability" Astrophys.J.Supple.78. 267-282 (1992)
• [文献書誌] Uchida,Y.: "A Magnetohydrodynamic Model for Herbig-Haro Objects:Magnetically Guided Shocked Flows Associated with Optical Jets from Young Stellar Objects" Publ.Astron.Soc.Japan. 44. 227-243 (1992)
• [文献書誌] Todo,Y.: "Behavior of Jets from young Stellar Objects in Large Scale Interstellar Magnetic Fields:MHD Model of Herbig-Haro Objects in 2.5D Simulation" Publ.Astron.Soc.Japan. 44. 245-263 (1992)
• [文献書誌] Todo,Y.: "Wiggled Structure of Herbig-Haro Objects:Helical Kink Instability of Jets from Young Stellar Objegts" Astrophys.J.403. 164-174 (1992)
• [文献書誌] Bodo,G.: "Non-linear Evolution of Synchrotron Thermal Instabilities" Astron.Astrophys.256. 689-700 (1992)
• [文献書誌] Stern,R.A.: "Coordinated Ginga,IUE,and VLA observations of Stellar Activity in σ^2 Coronae Borealis" Astron.Astrophys.391. 760-772 (1992)
• [文献書誌] Stern,R.A.: "GINGA Observations of X-ray Flares on Algol" Astrophys.J.400. 321-329 (1992)
• [文献書誌] Uchida,Y.: "The Solar-A Mission Experiments and The Targets" Eruptive Solar Flares,eds.Z.Svestka and B.Jackson.(Kulwer Publishers,Dordorecht). 309 (1992)
• [文献書誌] Ogawara,Y.: "New Vistas of Solar Physics Opened Up by satellite Yohkoh" COSPAR Information Bulletin. 124. 61-64 (1992)
• [文献書誌] Ogawara,Y.: "Status of Yohkoh in Orbit:An Introduction to the Initial Scientific Results" Publ.Astron.Soc.Japan. 44. L41-L44 (1992)
• [文献書誌] Hudson,H.: "White-light Flares Observed by Yohoh" Publ.Astron.Soc.Japan. 44. L77-L82 (1992)
• [文献書誌] Shimizu,T.: "Transient Brightenings in Active Regions Observed by the Soft X-ray Telescope on Yohkoh" Publ.Astron.Soc.Japan. 44. L147-L154 (1992)
• [文献書誌] Uchida,Y.: "Continual Expansion of Active Region Corona Observed with the Yohkoh Soft X-ray Telescope" Publ.Astron.Soc.Japan. 44. L155-L160 (1992)
• [文献書誌] Klimchuk,J.A.: "Thickness Variatios along Coronal Loops Observed by the Soft X-ray Telescope on Yohkoh" Publ.Astron.Soc.Japan. 44. L181-L186 (1992)
• [文献書誌] Acton,L.: "The Yohkoh Mission for High Energy Solar Physics" Science. 258. 618-625 (1992)
• [文献書誌] Fujimoto,M.Y.: "Two Component Gravitating Systems and Red-Giant Like Structure" Astrophysical Journal. 385. 445-459 (1992)
• [文献書誌] Tomisaka,K.: "The Evolution of a Magnetized Superbubble" Publications of Astronomical Society of Japan. 44. 177-191 (1992)