活動的天体における磁気流体現象の理論的研究

1991 Fiscal Year Annual Research Report

• Project/Area Number: 03302013
• Research Institution: National Astronomical Observatory of Japan
• Principal Investigator: 柴田 一成 国立天文台, 太陽物理学研究系, 助教授 (70144178)
• Co-Investigator(Kenkyū-buntansha): 佐藤 哲也 核融合科学研究所, 教授 (80025395) ; 沢 武文 愛知教育大学, 教育学部, 助教授 (90111864) ; 松元 亮治 千葉大学, 教養部, 助教授 (00209660) ; 内田 豊 東京大学, 理学部, 教授 (90012814) ; 花輪 知幸 名古屋大学, 理学部, 助手 (50172953)
• Keywords: 活動的天体 / 磁場 / 流体力学 / リコネクション / 磁気流体衝撃波 / アクリ-ション / ジェット / ダイナモ

Research Abstract

近年の電波、X線天文等の発展により、多くの活動的天体には磁場を伴ったプラズマの激しい運動が深く関与していることが次第に明らかになってきた。例えば、太陽(恒星)フレアとコロナ、原始星や活動銀河からのジェット、銀河円盤に見られるスパ-、等々である。1991年8月に打ち上げに成功した太陽X線観測衛星「ようこう」(SolarA)は、従来にもまして、太陽コロナがダイナミックな現象に満ち満ちていることを明らかにした。これらの天体活動現象を理解するには、磁気流体力学(MHD)の計算(非定常シミュレ-ションや安定性解析)とその解釈(一般理論、統一的描像の構築)が必要である。本総研はこのような研究を組織的に行うこと、特に異なる学会(天文、核融合、地球電磁気流体)を母体にする関連研究者間の交流の促進をはかること、を目的とした。
これらの目的を達成するために、本年度は2年計画の1年目として、MHDの基礎過程に関する小ワ-クショップを3回開催した。ワ-クショップ題目は次の通り。(1)天体におけるMHD不安定(参加者20数名;於野辺山宇宙電波観測所)。(2)天体における磁気リコネクション、乱流と波動、ダイナモ(参加者20数名;於愛知県蒲郡市)。(3)天体におけるwind、ジェット、アクリ-ション(参加者20数名;於名古屋大学)。ワ-クショップでは基礎過程、基礎物理に関するかなりつっこんだ議論を行なった。その結果多くの問題点が明らかにされ、議論のいくつかは共同研究(MHD不安定など)に発展した。ワ-クショップ集録として、天体におけるMHD不安定の文献リスト集を作成した。
また、名古屋大学にカラ-プリンタ、東京大学にハ-ドディスクを設置し、両地区の分担者の共同利用をはかった。

Research Products

• [Publications] Sterling,A.C.: "Numerical Simulations of Microflare Evolution in the Solar Transition Region and Corona" Astrophys.J.381. 313-322 (1991)
• [Publications] Shibata,k.: "Formation of Giant Molecular Clouds and Helical Magnetic Fields by the Parker Instability" Nature. 353. 633-635 (1991)
• [Publications] Nozawa,S.: "Emergence of Magnetic Flux from the Convection Zone into the Solar Atmosphere,I.Linear and Nonlinear Adiabatic Evolution of th ConvectiveーParker Instability" Astrophys.J.Suppl.78. 267-282 (1992)
• [Publications] Tajima,T.: "On the Origin Cosmological Magnetic Fields" Astrophys.J.(1992)
• [Publications] Shibata,K.: "Magnetic Reconnection Associated with Emerging Magnetic Flux" Publ.Astr.Soc.Japan. 44. (1992)
• [Publications] Matsumoto,R.: "Three Dimensional Simulation of the Parker Instability" Publ.Astr.Soc.Japan. (1992)
• [Publications] Hanawa,T.: "ParkerーJeans Instability of Magnetized Gaseous Disks," Publ.Astron.Soc.Japan. 43No.5. 685-702 (1991)
• [Publications] Hanawa,T.: "ParkerーJeans Instability of the Galactic Gaseous Disk" Publ.Astr.Soc.Japan. (1991)
• [Publications] Hanawa,T.: "Giant Molecular Cloud Formation throgh the Parker Instability in a Sheared Magnetic Field" Astrophys.J.(1991)
• [Publications] Uchida,Y.: "The SolarーA Mission and Its Scientific Aims" Phil.Trans.Boy.Soc.London A. 336. 485-495 (1991)
• [Publications] Uchida,Y.: "A Magnetodynamic Model for Herbig Haso Objects" Publ.Astron.Soc.Japan. 44. (1992)
• [Publications] Todo,Y.: "Behavior of Jets from Young Stellar Objects in Large Scale Magnetic Fields" Publ.Astron Soc.Japan. 44. (1992)
• [Publications] Sato,T.: "Role of compressibility on driven magnetic reconnection" Physics of Fluids B. 4. 450-457 (1992)
• [Publications] Horiuchi,R.: "Threeーdimensional Particle Simulation study on stabilization of the FRC tilting Instability" Plasma Physics and Controlled Nuclear Fusion Research IAEA VIENNA. 2. 283-288 (1991)
• [Publications] Kageyama,A.: "A Global Simulation of the magnetosphere with a long tail" No Interplanetary Magnetic Field.
• [Publications] Mineshige,S.: "SelfーSimilar Viscous Decay in DwarfーNova Outbursts" Mon.Notices.Roy.Astron Soc.250. 253-257 (1991)
• [Publications] Mineshige,S.: "Flywheels; Rapidly Rotating Magnetised Neutron Stars in Spherical Accretion" Mon.Notices.Roy.Astron Soc.252. 555-563 (1991)
• [Publications] Mineshige,S.: "Black Hole Accretion Disks Exhibiting Superhumps" Publ.Astron.Soc.Japan. 44. (1992)
• [Publications] Nagasawa,M.: "Mixing in Convective SupernovaーBubble Solution vs.Blast Wave Solution" Supernovae Tenth Santa Cruz Summer Workshop. 245-248 (1991)
• [Publications] Nagasawa,M.: "ThreeーDimensional Hydrodynamic calculation of an Accretion Disc by SPH Scheme" Frontiers of XーRay Astronomy. (1991)
• [Publications] Nagasawa,M.: "ThreeーDimensional Hydrodynamics of an Accretion Disk and Jet Formation" Active Galactic Nuclei:Heidelberg Conference. (1992)
• [Publications] Sakai,J.: "A Theory of Filament Eruptions before the Impulsive Phase of Solar Flares" Solar Physics. 137. 329-306 (1992)
• [Publications] Sakai,J.: "Prompt Particle Acceleration around Moving Xーpoint Magnetic Field during Inpulsive Phase of Solar Flares" Solar Physics. (1992)
• [Publications] Nakano,T.: "Magnetic fields in accretion disks around propostars and fragmentation of the disks" Memorie della Societa Astronomia Itariana.
• [Publications] Nishi,R.: "Magnetic flux loss from dense interstellar clouds with iceーmantled grains" Astrophys.J.
• [Publications] Matsuda,T.: "On the stability of wind accretion" Astronomy and Astrophsics. 248. 301-314 (1991)
• [Publications] Matsuda,T.: "Numerical simulations of twoーdimensional and threeーdimensional accretion flows" Monthly Notices of the Royal Astronomical Society. (1992)
• [Publications] Sawada,K.: "Threeーdimensional hydrodynamic simulation of an accretion flow in a close binary system" Monthly Notices of the Royal Astronomical Society. 255. 17-20 (1992)
• [Publications] Nitta,S.: "Effects of Magnetohydrodynamic Accretion Flows on Global Structure of a Kerr BlackーHole Magnetosphere" Physical Review D.44. 2295-2305 (1991)
• [Publications] Hirotani,K.: "Accretion in Kerr Black Hole Magnetosphere: Energy and Angular Momentum Transport between the Magnetic Field and the Matter" Astrophys.J.386. 455-463 (1992)
• [Publications] Umeki,H.: "Decay instability of incoherent Alfven waves" J.Geophys.Res.96. (1991)
• [Publications] Yokosawa,M.: "Extraction of Rotating Energy from a Black Hole by Frozen in Magnetic Field in Accretion Flow" Publications of the Astronomical Society of Japan. 43No.3. 427-447 (1991)
• [Publications] Yokosawa,M.: "Magnetohydrodynamic Accretion onto a Rotating Black Hole" Proceeding of Sixth Marcel Grossmann Meeting on General Relativity. (1991)
• [Publications] Yokosawa,M.: "Nonlinear Expansion Triggered by Magnetic Stress in Accretion Flow onto a Black Hole" Proceedings of International Astronomical Union Colloquim on Nonlinear Phenomena in Variable Stars. (1992)
• [Publications] Chiba,M.: "Spiralーarm resonance in galactic dynamos" Mon.Not.R.astr.Soc.250. 769 (1991)
• [Publications] Chiba,M.: "Swing excitation of galactic magnetic fields induced by spiral density waves" Mon.Not.R.astr.Soc.244. 714 (1990)
• [Publications] Hirotani,K.: "Time Variation of Magnetohydrodynamic Accretion onto a Rotating Black Hole" Astrophys.J.
• [Publications] Hayashi,T.: "Suppression of Magnetic Surface Breaking by Extra Coils in Finite Beta Equilibria of Helical Systems" Nuclear Fusion. 31. 1767-1770 (1991)
• [Publications] Hayashi,T.: "Equilibrium Beta Limit and Anomalous Tranport Studies of Helical Systems" Plasma Physics and Controlled Nuclear Fusion Research. 2. 143-150 (1991)
• [Publications] Hayashi,T.: "Magnetic Surface Breaking in Three Dimensional 1=2 Heliotron/Torsatron Equilibria" Physics of Fluids B. 4. NO.6 (1992)
• [Publications] Terasawa,T.: "Acceleration mechanisms for cometary ions" Geophys.Monograph. 61. 277-286 (1991)
• [Publications] Fujimoto,M.: "Ion inertia effect on the KelvinーHelmholtz instability" J.Geophys.Res.96. 15725-15734 (1991)
• [Publications] Ogino,T.: "A Global magnetohydrodynamic Simulation of the Magnetosheath and Magnetosphere when the Interplanetary Magnetic Field is Northward" IEEE. (1992)
• [Publications] Maezawa,K.: "Dependence of the Polar Rain Intensity on the Dawnーtodusk Component of the Convection Electric Field" Journal of Geophysical Research. (1992)
• [Publications] Kaburaki,O.: "Kerr Black Holes as a Carnot Engine" Phys.Rev.D.43. 340-345 (1991)
• [Publications] Kudoh,T.: "Magnetohydrodynamical Winds with Finite Electrical Conductivity" Sci.Rep.Tohoku Univ.8th Ser.11. 131-136 (1991)
• [Publications] Okamoto,I.: "The Third Law of Thermodynamics of Kerr Black Holes" M.N.R.A.S.250. 300-309 (1991)
• [Publications] Fukue,J.: "MagneticーPresure Driven Jets from a Torus" PASJ. 43. 131-145 (1991)
• [Publications] Tosa,M.: "Structure of magnetic fields generated by galactic dynamos" Astrophys.Geophys.Fluid Dyn.50. 147 (1990)
• [Publications] Wada,K.: "Rapid gas supply to a nuclear region in a weak barred potential by selfーgravitational instability" Mon.Not.Roy.Astron Soc.(1992)
• [Publications] Habe,A.: "Gravitational instability induced by a cloud cloud collision.The case of head on collision between clouds with different sizes and densities" Publ.Astron.Soc.Japan.
• [Publications] Habe,A.: "Triggering the collapse of selfーgravitating clouds by torsional Alfven waves" Publ Astron Soc.Japan. 43. 703-718 (1991)
• [Publications] Ugai,M.: "Computer Simulations of FieldーAligned Currents Generated by Fast Magnetic Reconnection in Three Dimensions" J.Geophys.Res.96. 21173-21181 (1991)
• [Publications] Ugai,M.: "Computer Modelling of Three Dimensional Dynamics of Fast Reconnection" J.Plasma Phys.45. 251-266 (1991)
• [Publications] Fukue,J.: "Tides in Space Colony" PASJ. 43. 657-660 (1991)
• [Publications] Fukue,J.: "On the Regulation of Jet Speed in SS433" PASJ. 44. (1992)
• [Publications] Inutsuka,S.: "SelfーSimilar Solutions and the Stability of Collapsing Isothermal Filaments" Astrophys.J.388. (1992)
• [Publications] Watanabe,S.: "Collision and Tidal Interaction between Planetesimals" Astrophys.J.(1992)
• [Publications] Miyama,S.M.: "Criteria for Collapse and Fragmentation of Rotating Clouds" Publ Astron.Soc.Japan. (1992)
• [Publications] Hachisu,I.: "Noulinear growth of RayleighーTaylor instabilities and mixing in SN1987A" Astrophys.J.(Letters). 358. L57-L61 (1990)
• [Publications] Hachisu,I.: "RayleigyーTaylor Instabilities and Mixing in the Helium Star Models for Type Ib/Ic Supernovae" Astrophys.J.(Letters). 368. L27-L30 (1991)
• [Publications] Hachisu,I.: "Mixing in Ejecta of Supernovae. I.General Properties of 2ーD RayleighーTaylor Instabilities and Mixing Width in Ejectaーof Supernovae" Astrophys.J.
• [Publications] 田中 基彦,西川 恭治: "高温プラズマの物理学" (株)丸善, 304 (1991)