初期宇宙の探求

1999 Fiscal Year Annual Research Report

• Project/Area Number: 07CE2002
• Research Institution: The University of Tokyo
• Principal Investigator: 佐藤 勝彦 東京大学, 大学院・理学系研究科, 教授 (00111914)
• Co-Investigator(Kenkyū-buntansha): 折戸 周治 東京大学, 大学院・理学系研究科, 教授 (10092173) ; 牧島 一夫 東京大学, 大学院・理学系研究科, 教授 (20126163) ; 釜江 常好 東京大学, 大学院・理学系研究科, 教授 (90011618) ; 吉井 譲 東京大学, 大学院・理学系研究科, 教授 (00158388) ; 野本 憲一 東京大学, 大学院・理学系研究科, 教授 (90110676)
• Keywords: 宇宙の大構造 / 超新星 / 銀河団 / 暗黒物質 / 反物質 / 宇宙X線γ線 / 科学衛星 / 宇宙の化学進化

Research Abstract

最終年度である今年度は各グループともに5年間の成果をまとめる事ができた。
1.銀河団の宇宙線起源γ線の性質を調べた。超新星コアでのニュートリノの物質との相互作用を調べた。Q-ballの性質、宇宙磁場の起源、多次元宇宙の諸性質を明らかにした。
2.「あすか」を用い、太陽の約100倍の質量をもつ回転ブラックホールが、系外銀河に存在する証拠を固め、また銀河群で激しい粒子加速が生じている観測的な証拠をえた。硬X線検出器(HXD)を完成させ、環境試験および地上較正試験を経て、ASTRO-E衛星に搭載した。平成12年2月10日の衛星打ち上げは痛恨ながらロケットの不具合のため失敗に帰したが、直ちに再挑戦に向け始動している。宇宙ガンマ線観測では、米国で計画中のGLAST衛星にシリコンストリップ検出器が正式に採択され、我々の開発が将来に直結する見通しが開けた。
3.カナダLynnlakeに於いて太陽活動中庸期における反陽子、一次宇宙線の観測を行った。異なる大気深さ(上昇中:800g/cm^2〜5g/cm^2、乗鞍山々頂:700g/cm^2)での電子、ミュー粒子、反陽子等の宇宙線スペクトルを測定した。これまで蓄積したデータを解析し、研究の総括を行った。
4.原始銀河・球状星団の形成過程のシミュレーションにより、星系の化学的力学的特徴をよく再現するモデルの構築に成功した。いくつかの特異な超新星を解析し、ガンマ線バーストを起こすほどの大爆発であることを明らかにした。Ia型超新星の分散の原因をつきとめ宇宙論への応用の基礎を強固にした。
5.MAGNUM望遠鏡は米国の工場で機能試験を行った後、ハレアカラ観測所に運搬しファーストライトを果した。またビームスプリッタ及びフィルタの性能向上、カメラ制御ソフトウェアの開発、各ソフトウエアのコンポーネントの統合・試験を始め、雲量監視装置の試験観測を開始した。
6.スローンディジタルスカイサーベイの試験観測で得られたデータを解析し、最遠記録を塗り替えるものを含む遠方のクエーサー、低温褐色矮星などを発見した。銀河進化に関する観測的制限を調査し、測光的赤方偏移の推定法を改良した。すばるを用いた初期試験観測を行った。
7.超重力理論と重い右巻ニュートリノの崩壊による宇宙のバリオン数生成メカニズムとの整合性について調べた。これは宇宙のインフレーションのメカニズムに大きく依存する。私達は、超重力子の問題を回避でき、しかも充分な宇宙のバリオン数を生成できる自然なインフレーション模型を超重力理論の枠組のなかで発見した。
8.昨年度に引き続き、富士山頂サブミリ波望遠鏡を用いて中性炭素原子の492GHzのスペクトル線の広域観測を遂行した。その結果、新たに15平方度の領域をサーベイでき、分子雲形成過程が雲によって大きく異なることを見出した。中性炭素原子の809GHzスペクトル線の観測にも成功した。
9.高赤方偏移天体の宇宙論的統計解析における光円錐効果の重要性を指摘し、定式化した。宇宙論的赤方偏移効果の観測可能性をシミュレーションを用いて検証した。
10.ボロメータによる暗黒物質の直接検出実験では、宇宙線の影響が十分少ない神岡宇宙素粒子研究施設に装置を移設し、定常的な観測が行なわれた。超伝導電磁石による太陽axion検出実験では、磁場領域を極低温高密度のヘリウムガスで満しX線が見かけ上質量を持つようにし、質量が1電子ボルト弱程度のアクシオンに感度が出るようにした。
11.本年度は超重力理論の枠組で構築したニュー・インフレーション・モデルに関して、その初期値問題を解決するためにプレ・インフレーションを導入した場合の宇宙の大規模構造の形成に与える影響を調べ,このモデルが観測された銀河分布を良く再現できることが分かった。
12.銀河初期の化学進化を記述する新しいモデルを提案し、観測された重元素量に対する星の個数分布を再現した。観測されたBa/Mg-Mg/Hの組成比の相関を用いてr過程によって合成される元素の起源を特定し、Euの組成に対してSUBARUで検証可能な予言を行った。

Research Products

• [Publications] K.Yoshikawa: "Reconstructing the radial profiles of gas density and temperature in clusters of galaxies from high-resolution X-ray and radio observations"Ap.J.. 513. 549-554 (1999)
• [Publications] E.Komatsu: "Submillimeter detection of the Sunyaev--Zel'dovich effect toward the most luminous X-ray cluster at z=0.45"Ap.J.(Letters). 516. L1-L4 (1999)
• [Publications] K.Yamamoto: "Two-point correlation functions of high-redshift objects : an explicit formulation on a light-cone hypersurface"Ap.J.. 517. 1-12 (1999)
• [Publications] Y.Suto: "Deciphering cosmological information from redshift surveys of high-z objects--the cosmological light-cone effect and redshift-space distortion--"Prog.Theo.Phys.Supp.. 133. 183-210 (1999)
• [Publications] K.Yamamoto: "The cosmological light-cone effect on the power spectrum of galaxies and quasars in wide-field redshift surveys"Ap.J.. 527. 488-497 (1999)
• [Publications] H.Magira: "Cosmological Redshift-space distortion on clustering of high-redshiftobjects : correction for nonlinear effects in power spectrum and tests with N-body simulations"Ap.J.. 528. 30-50 (2000)
• [Publications] Y.Suto: "Cosmological implications of galaxy clusters in X-ray, millimeter and submillimeter bands"Adv.Space Res.. 25. 771-780 (2000)
• [Publications] Y.P.Jing: "Density Profiles of Dark Matter Halo are not Universal"Ap.J.(Letters). 529. L69-L72 (2000)
• [Publications] T.Tsujimoto: "Chemical Evolution of the Galactic Halo through Supernova-Induced Star Formation and Its Implication for Population III Stars"Ap.J.. 519. L63-L67 (1999)
• [Publications] R.Saito: "A Possible Model Of Persistent X-Ray-Luminous Gas Around The Giant Elliptical Galaxy M87"Ap.J.. 519. 48-54 (1999)
• [Publications] T.Tsujimoto: "Probing the Sitefor R-Process Nucleosynthesis with Abundances of Barium And Magnesium In Extremely Metal-Poor Stars"Ap.J.. 531. L33-L36 (2000)
• [Publications] H.Maezawa: "Large-Scale Mapping Observations of the CI 3P1-3P0 Line toward Heiles Cloud 2 in the Taurus Dark Cloud"Ap.J.. 524. L129-L132 (1999)
• [Publications] M.Ikeda: "Large-Scale Mapping Observations of the CI(3P1-3P0)and CO(J=3-2)Lines toward the Orion A Molecular Cloud"Ap.J.. 527. L59-L62 (1999)
• [Publications] Y.Terada: "A Peculiar X-Ray Transient Source, AX J1842.8-0423,Discovered with ASCA"Publ.Astr.Soc.Japan. 51. 39 (1999)
• [Publications] J.Sato: "Improvement of YOHKOH Hard X-Ray Imaging"Publ.Astr.Soc.Japan. 51. 127 (1999)
• [Publications] T.Syuniti: "Magnetic Reconnection as the Origin of Galactic-Ridge X-Ray Emission"Publ.Astr.Soc.Japan. 51. 161 (1999)
• [Publications] K.Kikuchi: "ASCA Measurements of Metallicity and Temperature Distributions in Three Clusters : A4059,MKW 3s, and 2A 0335+096"Publ.Astr.Soc.Japan. 51. 301 (1999)
• [Publications] T.Mizuno: "ASCA Observations of Two Ultra-Luminous Compact X-Ray Sources in the Edge-On Spiral Galaxy NGC 4565"Publ.Astr.Soc.Japan. 51. 663 (1999)
• [Publications] U.Hwang: "Mass and Metallicity of Five X-Ray-bright Galaxy Groups"Ap.J.. 516. 604 (1999)
• [Publications] Y.Ueda: "LogN-LogS Relations and Spectral Properties of Sources from the ASCA Large Sky Survey : Their Implications for the Origin of the Cosmic X-Ray Background (CXB)"Ap.J.. 518. 656 (1999)
• [Publications] Y.Ueda: "The ASCA Medium-Sensitivity Survey (The GIS Catalog Project) : Source Counts and Evidence for Emerging Population of Hard Sources"Astrophys.J.. 524. L11 (1999)
• [Publications] I.Yasushi: "Two-Phase Intracluster Medium in the Centaurus Cluster of Galaxies"Astrophys.J.. 525. 58 (1999)
• [Publications] K.Makishima: "Cyclotron Resonance Effects in Two Binary X-Ray Pulsars and the Evolution of Neutron Star Magnetic Fields"Astrophys.J.. 525. 978 (1999)
• [Publications] J.Kataoka: "Variability Pattern and the Spectral Evolution of the BL Lacertae Object PKS 2155-304"Astrophys.J.. 528. 243 (2000)
• [Publications] K.Kikuchi: "Detection of an X-Ray Hot Region in the Virgo Cluster of Galaxies with ASCA"Astrophys.J.. 531. L95 (2000)
• [Publications] Y.Fukazawa: "Statistical Properties of Metal Abundances of the Intracluster Medium in the Central Region of Clusters"Mon.Not.Roy.Astr.Soc.. 313. 21 (2000)
• [Publications] D.Watson: "Simultaneous Multifrequency Observations of the BL Lac MS 0205.7+3509"A & A. 345. 414 (1999)
• [Publications] K.Makishima: "Energy Non-Equipartition Processes in the Universe"Astron.Nach.. 320. 163 (1999)
• [Publications] Y.Fukazawa: "ASCA Observations of Non-Thermal Emissions from Groups of Galaxies"Astron.Nach.. 320. 197 (1999)
• [Publications] M.Tashiro: "ASCA Measurements of Non-Thermal Pressures in the Radio Lobes"Astron.Nach.. 320. 217 (1999)
• [Publications] K.Nakazawa: "ASCA Observation of Diffuse X-ray Source RXJ1833.6+6520, a Candidate for Dark Cluster?"Astron.Nach.. 320. 294 (1999)
• [Publications] N.Iyomoto: "Long-Term Variability of the M81 Nucleus"Astron.Nach.. 320. 300 (1999)
• [Publications] M.Sugibo: "ASCA Observation of the BL Lac Object PKS 1413+135 Embedded in a Spiral Galaxy"Astron.Nach.. 320. 316 (1999)
• [Publications] A.Kubota: "ASCA Observations of the X-ray Transient XTE J1550-564:Change of Accretion Disk Parameters"Astron.Nach.. 320. 353 (1999)
• [Publications] T.Mizuno: "ASCA Observation of Ultra-Luminous X-Ray Sources and Interpretation of their Nature"Astron.Nach.. 320. 356 (1999)
• [Publications] Y.Matsumoto: "Angular Response of the Hard X-Ray Detector (HXD) onboard ASTRO-E"Astron.Nach.. 320. 356 (1999)
• [Publications] Y.Terada: "The Digital Data Processing System of the ASTRO-E Hard X-Ray Detector"Astron.Nach.. 320. 377 (1999)
• [Publications] W.Ootani: "First Results from Dark Matter Search Experiment in the Nokogiriyama Underground Cell"Phys.Lett.. B461. 371-375 (1999)
• [Publications] X.Fan: "High-Redshift Quasars Found in Sloan Digital Sky Survey Commissioning Data"Astron.J.. 118. 1-13 (1999)
• [Publications] X.Fan: "High-Redshift Quasars Found in Sloan Digital Sky Survey Commissioning Data. II. The Spring Equatorial Stripe"Astron.J.. 119. 1-11 (2000)
• [Publications] X.Fan: "L Dwarfs Found in Sloan Digital Sky Survey Commissioning Imaging Data"Astron.J.. 119. 928-935 (2000)
• [Publications] H.Hanami: "Merging Young Clusters in the Shapley Supercluster"Astrophys.J.. 521. 90-98 (1999)
• [Publications] X.Fan: "The Discovery of a High-Redshift Quasar without Emission Lines from Sloan Digital Sky Survey Commissioning Data"Astrophys.J.. 526. L57-L60 (1999)
• [Publications] F.Nakata: "Probing the evolution of early-type galaxies using multicolour number counts and redshift distributions"MNRAS. 309. L25-L29 (1999)
• [Publications] N.Kaifu: "The First Light of the Subaru Telescope : A New Infrared Image of the Orion Nebula"Publ.Astron.Soc.Japan. 52. 1-8 (2000)
• [Publications] M.Iye: "Subaru First-Light Deep Photometry of Galaxies in A851 Field"Pub.Astron.Soc.Japan. 52. 9-24 (2000)
• [Publications] Y.Komiyama: "High-Resolution Images of the Ring Nebula Taken With the Subaru Telescope"Pub.Astron.Soc.Japan. 52. 93-98 (2000)
• [Publications] S.Okamura: "Color of Dwarf Galaxies in the Coma Cluster"in IAU Symp.183 'Cosmological Parameters and the Evolution of the Universe' (ed.K.Sato : Dordrecht, Boston : Kluwer Academic). 160 (1999)
• [Publications] W.Kawasaki: "Possible Supercluster at z&sim ; 0.25 towards the South Galactic Pole"in IAU Symp.183 'Cosmological Parameters and the Evolution of the Universe' (ed.K.Sato : Dordrecht, Boston : Kluwer Academic). 254 (1999)
• [Publications] K.Shimasaku: "Measuring the Density Fluctuation From the Cluster Gas Mass Function"in IAU Symp.183 'Cosmological Parameters and the Evolution of the Universe' (ed.K.Sato : Dordrecht, Boston : Kluwer Academic). 267 (1999)
• [Publications] M.Yagi: "Type-Specific Luminosity Functions of Nearby Clusters of Galaxies"in IAU Symp.183 'Cosmological Parameters and the Evolution of the Universe' (ed.K.Sato : Dordrecht, Boston : Kluwer Academic). 272 (1999)
• [Publications] S.Okamura: "The Sloan Digital Sky Survey is about to start"Newsletter No.11 of Working Group on Sky Surveys, IAU Com.9. 11-19 (1999)
• [Publications] S.Tsubaki: "The Cosmic Ray Induced Gamma Rays in the Coma and Virgo Clusters"Prog.Theor.Phys.. 101. 1391-1396 (1999)
• [Publications] S.Yamada: "Neutrino-nucleon reaction rates in the supernova core in the relativistic random phase approximation"Phys.Rev.C. 61. 015803-1-015803-16 (2000)
• [Publications] S.Yamada: "Reduction of neutrino-nucleon scattering rate by nucleon-nucleon collisions"Nucl.Phys.A. 662. 219-232 (2000)
• [Publications] T.Shiromizu: "Generation of a magnetic field due to excited Q-balls"Phys.Rev.D. 58. 107301-1-107301-4 (1999)
• [Publications] T.Shiromizu: "Perturbation analysis of deformed Q-balls and primordial Magnetic field"Phys.Rev.D. 59. 125010-1-125010-8 (1999)
• [Publications] T.Shiromizu: "Gravitational mass in asymptotically de Sitter space-times with compactified dimensions"Phys.Rev.D. 60. 064019-1-064019-5 (1999)
• [Publications] T.Shiromizu: "Stringy probe particle and force balance"Phys.Rev.D. 60. 104046-1-104046-6 (1999)
• [Publications] T.Shiromizu: "Space-Times which are asymptotic to certain FRW space-times at Timelike Infinity"Class.Quant.Grav.. 16. 2955 (1999)
• [Publications] T.Shiromizu: "Dilatonic Probe, Force Balance and Gyromagnetic Ratio"Phys.Lett.B. 460. 141 (1999)
• [Publications] H.Yahagi: "The forest method as a new parallel tree method with the section voronoi tessellation"Astrophys.J.Supp.. 124. 1-9 (1999)
• [Publications] T.Tsujimoto: "Chemical evolution of the galactic halo through supernovainduced star formation and its implication for population III stars"Astrophys.J.Lett.. 519. 63-67 (1999)
• [Publications] T.K.Suzuki: "Evolution of beryllium and boron in the inhomogeneous early galaxy"Astrophys.J.Lett.. 522. 125-128 (1999)
• [Publications] T.Tsujimoto: "Probing the Site for R-Process Nucleosynthesis with Abundances of Barium and Magnesium in Extremely Metalpoor Stars"Astrophys.J.. 531. L33-L36 (2000)
• [Publications] M.Chiba: "Three-dimensional kinematics of metal-poor stars revealed from HIPPARCOS observations"The Third Stromlo Symp."The Galactic Halo". 269-273 (1999)
• [Publications] T.Tsujimoto: "The absolute magnitude of RR Lyrae stars derived from the hipparcos catalogue"ASP conf.. 167. 332-335 (1999)
• [Publications] S.Orito: "Precision Measurement of Cosmic-Ray Antiproton Spectrum"Phys.Rev.Lett.. 84・6. 1078-1081 (2000)
• [Publications] Z.Wang: "Measurement of Cosmic-Ray H and He Isotopes in a Series of Annual Balloon Flights"Proc.26th Intl.Cosmic Ray Conf.. 3. 37-40 (1999)
• [Publications] K.Yoshimura: "Measurement of Cosmic-Ray Antiproton Spectrum in the Energy Range 0.18 to 3.56〜GeV at Solar Minimum"Proc.26th Intl.Cosmic Ray Conf.. 3. 81-84 (1999)
• [Publications] M.Nozaki: "A Search for Antihelium down to 10^<-6> Relative to Helium"Proc.26th Intl.Cosmic Ray Conf.. 3. 85-88 (1999)
• [Publications] T.Sanuki: "A Precise Measurement of Cosmic-Ray Proton Spectrum with BESS Spectrometer"Proc.26th Intl.Cosmic Ray Conf.. 3. 93-96 (1999)
• [Publications] M.Kawasaki: "Primordial Black Hole Formation in Supergravity"Phys.Rev.. D59. 043512-1-043512-7 (1999)
• [Publications] T.Asaka: "Cosmological Moduli Problem and Oscillating Inflation in Gauge-Mediated Supersymmetry Breaking"Phys.Lett.. B451. 317-323 (1999)
• [Publications] M.Yamaguchi: "Evolution of Axionic Strings and Spectrum of Axions Radiated from Them"Phys.Rev.Lett.. 82. 4578-4581 (1999)
• [Publications] M.Kawasaki: "Cosmological constraints on late-time entropy production"Phys.Rev.Lett.. 82. 4168-4171 (1999)
• [Publications] K.-I.Izawa: "R-invariant Topological Inflation"Prog.Theor.Phys.. 101. 1129-1133 (1999)
• [Publications] T.Asaka: "Superheavy Dark Matter and Thermal Inflation"Phys.Rev.. D60. 103518-1-103518-6 (1999)
• [Publications] T.Asaka: "Cosmological Moduli Problem and Thermal Inflation Models"Phys.Rev.. D60. 123509-1-123509-25 (1999)
• [Publications] T.Asaka: "Leptogenesis in Inflaton Decay"Phys.Lett.. B464. 12-18 (1999)
• [Publications] T.Asaka: "Initial Condition for New inflation in Supergravity"Phys.Rev.. D61. 027303-1-027303-4 (2000)
• [Publications] T.Kanazawa: "Double Inflation in Supergravity and the Large Scale Structure"Phys.Rev.. D61. 023517-1-023517-9 (2000)
• [Publications] S.Kasuya: "Q-ball Formation through Affleck-Dine Mechanism"Phys.Rev.. D61. 041301-1-041301-4 (2000)
• [Publications] K.Nomoto: "Supernova Nucleosynthesis, Chemical Evolution, and Cosmic Supernova Rate"Astrophys.Sp.Sci.. 265. 37-47 (1999)
• [Publications] K.Nomoto: "A Hypernova Model for the Peculiar Type Ic Supernova 1997ef"Astron.Nach.. 320. 265-268 (1999)
• [Publications] M.Itoh: "X-ray Light Curve of SN1987A Observed with ASCA"Astron.Nach.. 320. 333 (1999)
• [Publications] C.Kobayashi: "Cosmic Supernova Rates in Cluster vs.Field Galaxies"Astron.Nach.. 320. 334 (1999)
• [Publications] S.Kumagai: "Models of Type Ia Supernovae"Astron.Nach.. 320. 336 (1999)
• [Publications] T.R.Young: "Binary Supernovae : A Theoretical Study of Double Explosions"Astron.Nach.. 320. 345 (1999)
• [Publications] T.Nakamura: "A 'Hypernova' Model for the Supernova 1998bw Possibly Associated with GRB980425"Astron.Nach.. 320. 363 (1999)
• [Publications] H.Umeda: "Evolution of 3-9 Mo Stars for Z=0.001-0.03 and Metallicity Effects on Type Ia Supernovae"Astrophys.J.. 513. 861-868 (1999)
• [Publications] C.Chiappini: "The Earliest Phases of Galaxy Evolution"Astrophys.J.. 515. 226-238 (1999)
• [Publications] T.Nakamura: "Nucleosynthesis in Type II Supernovae and the Abundances in Metal-Poor Stars"Astrophys.J.. 517. 193-208 (1999)
• [Publications] I.Hachisu: "A New Evolutionary Path to Type Ia Supernovae : Reexamination of Luminous Supersoft X-Ray Sources"Astrophys.J.. 519. 314-323 (1999)
• [Publications] H.Umeda: "The Origin of Diversity of Type Ia Supernovae and Environmental Effects"Astrophys.J.. 522. L43-L47 (1999)
• [Publications] I.Hachisu: "A Wide Symbiotic Channel of Type Ia Supernovae"Astrophys.J.. 522. 487-503 (1999)
• [Publications] S.Wanajo: "Nucleosynthesis in ONeMg Novae : Models vs. Observations to Constrain the Masses of ONeMg White Dwarfs and Their Envelopes"Astrophys.J.. 523. 409-431 (1999)
• [Publications] H.Umeda: "The Ejection of Relativistic Bullets from Supernovae and the Generation of Gamma-Ray Bursts"Astrophys.J.. 528. L89-L93 (2000)
• [Publications] K.Iwamoto: "Nucleosynthesis in Chandrasekhar Mass Models for Type Ia Supernovae and Constraints on Progenitor Systems and Burning Front Propagation"Astrophys.J.Supp.. 125. 439-462 (1999)