• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to project page

1998 Fiscal Year Annual Research Report

初期宇宙の探求

Research Project

Project/Area Number 07CE2002
Research InstitutionThe 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) 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)
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)
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 / 科学衛生 / 宇宙の化学進化
Research Abstract

昨年度に引続き、各グループともに着実に成果を挙げている。また、国際評価委員会によるレビューを受け高い評価を得た。
1. 軟X線および硬X線を用いた深宇宙探査Astro-E硬X線検出器実機の全コンポーネントを12月初旬の完成させ、組上ながら、種々の性能試験と校正を行なった。現在までに設計性能が概ね達成できていることを確認済。1999年4月末まで幾つかの不具合を修正し、11年度6月中旬に、衛星への組み込み作業に移行する予定である。「あすか」衛星を用い、核の活動が終息した電波銀河を発見、活動核の進化の証拠を得た。銀河群から非熱的X線を検出、銀河間空間での粒子加速の手掛かりを得た。ミリ秒パルサーから荷電粒子加速の証拠となる鋭い硬X線パルスを発見した。銀河団中の電離ガスから、化学組成進化の様子を明らかにした。
2. 活動銀河の多波長モニター観測による宇宙論望遠鏡は、主要部品の製作を終え仮組立てを開始し、全体を制御するソフトウェアの開発を進めた。主要な観測機器である多波長カメラは、電気系最適化と性能評価がほぼ終了し、これで観測装置まで含めた望遠鏡の総合調整を始める準備が整った。ハレアカラ観測所では、望遠鏡設置予定のドームの改修作業を着手した。
3. スローン・ディジタル・スカイサーベイによる広域銀河データベースの構築
10年5月に、待望の撮像モードでのファーストライトに漕ぎつけた。複雑でかつ多数のコンポーネントからなるSDSS計画をファーストライトにこぎ着けたこと自体が研究成果の一部である。9月のテスト観測のデータから、12個の遠方の新しいクエーサーを発見した。この内一つはこれまでのクエーサーの最遠記録を更新した。
4. サブミリ波望遠鏡による中性炭素原子の銀河広域観測富士山頂サブミリ波望遠鏡は、7月にヘリコプターにて山頂に設置された。9月に中性炭素原子線の初受信に成功し、11月から東大からの遠隔制御にて観測を行なっている。その結果、15平方度に及ぶ領域の中性炭素原子分布をはじめて明らかにした。希薄な星間雲から分子雲コアが作られる様子を捉えることができた。
5. 粒子線観測による宇宙初期・素粒子現象の探求
カナダLynnLakeにて気球実験を行い、各種宇宙線(反陽子・陽子、電子等)の測定を行った。Aerogel Cherenkov Counterの改良により、宇宙線反陽子を4GeV以下の領域で累計約1000例観測し、衝突起源反陽子からの2GeV付近のピークを鮮明に同定した。
6. 高感度ボロメータによる暗黒物質の直接検出
ボロメータによる暗黒物質の直接検出実験では暗黒物質素粒子と陽子の断面積に対する上限値を出し、5GeV以下の質量領域では世界最高の感度を実現している。超伝導電磁石による太陽axion検出実験では、アクシオンと光子の結合定数に0.03eV以下の質量領域で世界最高の制限をつけることができた。
7. 数値シュミレーションによる初期宇宙の探求
虚時間での宇宙定数をもった高次元重力場の方程式を解析し、力学系とアトラクターが存在することを発見した。宇宙はまず高次元の宇宙として生まれそれが3+1次元の空間と内部空間に進化するモデルを構築することができた。ビッグバン元素合成の計算と観測が一致するバリオン、レプトン数密度に関する制限を解析し求めた。光速度の有限性に起因する効果が2点相関関数に及ぼす影響を定式化した。将来の高空間分解能のX線及び電波観測から銀河団の密度・温度分布を再構築する方法を提唱した。ハワイマウナケア山のJCMTサブミリ波望遠鏡を用いて、サブミリ波SZ効果検出に世界で初めて成功した。
極超新星とガンマ線バーストの研究:観倒された可視光の光度曲線とスペクトルを数値モデルと比較し、ガンマ線バーストをひき起こした超新星1998bwが、通常の超新星の30倍ものエネルギーで爆発した極超新星であることを明らかにした。Hypernovaの元素合成と化学進化への影響を調べた。
8. 素粒子の統一理論と初期宇宙
スーパーカミオカンデの発見したニュートリノ振動現象はミューオン型ニュートリノとタウ型ニュートリノが大きく混合していることを示している。クオーク間の混合角が全て小さい事を考えると一見不思議な事に思える。本研究で、この大きな混合角がSU(5)の大統一理論では自然に説明できることを示した。

  • Research Products

    (97 results)

All Other

All Publications (97 results)

  • [Publications] J.P.Finley: "A Broadband X-Ray Study of the Young Neu-tron Star PSR B1706-44" Ap.J.493. 884 (1998)

  • [Publications] Fukazawa,Y.: "ASCA Measurements of Silicon and Iron Abun-dances in the Intracluster Medium" Publ.Astr.Soc.Japan. 50. 187 (1998)

  • [Publications] Ota,N.: "ASCA Observations of the Lensing Clusters CL0500-24,CL 2244-02,and A370:Mass Determi-nations and Comparisons" Ap.J.495. 170 (1998)

  • [Publications] Tamura,T.: "ASCA Observations of a Nearby and Massive Galaxy Cluster Abell 3627" Publ.Astr.Soc.Japan. 50. 195 (1998)

  • [Publications] Xu,H.: "Discovery of the Central Excess Brightness in Hard X-Rays in the Cluster of Galaxies Abell 1795" Ap.J.500. 738 (1998)

  • [Publications] Iyomoto,N.: "Low-Luminosity X-Ray Active Galactic Nuclei in So Galaxies NGC 3065 and NGC 4203" Ap.J.503. 168 (1998)

  • [Publications] Fukazawa,Y.: "ASCA Measurements of Silicon and Iron Abun-dances in the Intracluster Medium" Publ.Astr.Soc.Japan. 50. 187-193 (1998)

  • [Publications] Tamura,T.: "ASCA Observations of a Nearby and MassiveG-alaxy Cluster Abell 3627" Publ.Astr.Soc.Japan. 50. 195-201 (1998)

  • [Publications] Obayashi,H.: "ASCA Observations of the Sculptor Supercluster" Publ.Astr.Soc.Japan. 50. 537-545 (1998)

  • [Publications] Kubota,A.: "Evidence for a Black Hole in the X-ray Transient GRS 1009-45" Publ.Astr.Soc.Japan. 50. 667-673 (1998)

  • [Publications] Ueda,Y.: "A Population of Faint Galaxies that Contribute to the Cosmic X-ray Background" Nature. 391. 866-868 (1998)

  • [Publications] Terashima,Y.: "An ASCA Observation of M51(NGC5194):Iron K Emission from an Obscured Active Galactic Nucleus" Ap.J.496. 210-215 (1998)

  • [Publications] Tashiro,M.: "Evidence of Energy Nonequipartition between Par-ticles and Fields in Lobes of the Radio Galaxy PKS 1343-601(Centaurus B)" Ap.J.499. 713-718 (1998)

  • [Publications] Matsushita,K.: "Greatly Extended X-Ray Emission around the Elliptical Galaxy NGC 4636 Observed with ASCA" Ap.J.(Letters). 499. L13-L16 (1998)

  • [Publications] Xu,H.: "Discovery of the Central Excess Brightness in Hard X-rays in Abell 1795" Ap.J.500. 738-749 (1998)

  • [Publications] Iyomoto,N.: "The Declined Activity in the Nucleus of NGC 1316" Ap.J.(Letters). 500. L31-L34 (1998)

  • [Publications] Iyomoto,N.: "Low-Luminosity X-Ray Active Galactic Nuclei in SO Galaxies NGC3065 and NGC4203" Ap.J.503. 168-173 (1998)

  • [Publications] Kubo,H.: "ASCA Observations of Blazars and Multiband Analysis" Ap.J.504. 693-701 (1998)

  • [Publications] Takahashi,T.: "The Electronic System for the ASTRO-E Hard X-ray Detector" SPIE. 3445. 155-168 (1998)

  • [Publications] W.Ootani: "Performance of a Lithium Fluoride Bolometer for Tokyo Dark Matter Search Experiment" Astropart.Phys.9. 325-329 (1998)

  • [Publications] S.Moriyama: "Direct Search for Solar Axions by Using Strong Magnetic Field and X-ray Detectors" Phys.Lett.B434. 147-152 (1998)

  • [Publications] Kobayashi,C.: "Low-Metallicity Inhibition of Type Ia Supernovae and Galactic and Cosmic Chemical Evolution" Ap.J.503. L155-L159 (1998)

  • [Publications] Shigeyama,T.: "Fossil Imprints of the First-Generation Super-nova Ejecta in Extremely Metal-deficient Stars" Ap.J.507. L135-L139 (1998)

  • [Publications] Tsujimoto,T.: "New Insights into the Early Stage of the Galactic Chemical Evolution" Ap.J.508. L151-L154 (1998)

  • [Publications] Galama,T.: "An Usual Supernova in the Error Box of the γ-Ray Burst of 25 April 1998" Nature. 395. 670-672 (1998)

  • [Publications] Iwamoto,K.: "A Hypernova Model for SN 1998bw and the γ-Ray Burst of 25 April 1998" Nature. 395. 672-674 (1998)

  • [Publications] Shimasaku,K.and Fukugita,M.: "The History of Galaxies and Galaxy Number Counts" Ap.J.501. 578-596 (1998)

  • [Publications] Gunn,J.E.: "The Sloan Digital Sky Survey Photometric Cam-era" A.J.116. 3040-3081 (1998)

  • [Publications] Y.Asaoka: "Development of a Large-area Aerogel Chrenkov Counter onboard BESS" Nucl.Inst.and Method. A416. 236-242 (1998)

  • [Publications] H.Matsunaga: "Measurement of Low-Energy Cosmic-ray Antipro-tons at Solar Minimum" Phys.Rev.Lett.81. 4052-4055 (1998)

  • [Publications] Nakamura,T.: "Cosmological Redshift Distortion:Deceleration,Bias and Density Parmeters from Future Red-shift Surveys of Galaxies" Ap.J.494. 13-19 (1998)

  • [Publications] Suginohara,M.: "Cross-correlating Cosmic Microwave Background Radiation Fluctuations with Redshift Surveys:Detecting the Signature of Gravitational Lensing" Ap.J.495. 511-515 (1998)

  • [Publications] Suginohara,T.: "The Effect of Cooling on the Density Profile of Hot Gas in Clusters of Galaxies:Is Additional Physics Needed?" Ap.J.507. 16-23 (1998)

  • [Publications] Suto,Y.: "Gas Density and X-ray Surface Brightness Pro-files of Clusters of Galaxies from Dark Matter Halo Potentials:Beyond the Isothermal β-model" Ap.J.509. 544-550 (1998)

  • [Publications] J.Sato: "Large Lepton Mixing in a Coset Space Family Unification on e(7)" Phys.Lett.B430. 127-131 (1998)

  • [Publications] Y.Nomura.: "A Gauge Mediation Model of Dynamical Super-symmetry Breaking Without Color Instability" Phys.Lett.B・425. 107-113 (1998)

  • [Publications] J.Hisano: "Atomospheric Neutrino Oscillation and Large Lep-ton Flavor Violation in The SUSY SU(5)GUT" Phys.Lett.B437. 351-358 (1998)

  • [Publications] T.Asaka: "Cosmological Moduli Problem in Gauge Medi-ated Supersymmetry Breaking Theories" Phys.Rev. D58. 083509 (1998)

  • [Publications] T.Asaka: "Spectrum of Background X-Ray From Moduli Dark Matter" Phys.Rev. D58. 023507 (1998)

  • [Publications] M.Hashimoto: "Axion Cosmology with its Scalar Superpartner" Phys.Lett.B437. 44-50 (1998)

  • [Publications] T.Kanazawa: "Isocuvature Fluctuations of The M Theory Axion in a Hybrid Inflation Model" Prog.Theor.Phys.100. 1055-1062 (1998)

  • [Publications] M.Kawasaki: "Primodial Black Hole Formation in a Double In-flation Model in Supergravity" Phys.Rev.D57. 6050-6056 (1998)

  • [Publications] T.Han: "A jioint Messenger and Perturbative Unification at The String Scale" Phys.Rev.D58. 095011 (1998)

  • [Publications] M.Hashimoto: "Gravitino Overproduction Through Moduli De-cay" Prog.Theor.Phys.100. 395-398 (1998)

  • [Publications] M.Hamaguchi: "Superheavy Dark Matter with Discrete Gauge Symmetries" Phys.Rev. D58. 103503 (1998)

  • [Publications] Minezaki,T.: "The Interpretation of Near-Infrared Star Counts at the South Galactic Pole" A.J.115. 229-233 (1998)

  • [Publications] Tsujimoto,T.: "The Absolute Magnitude of RR Lyrae Stars De-rived from the Hipparcos Catalogue" A.J.(Letters). 492. 79-82 (1998)

  • [Publications] Minezaki,T.: "K-Band Galaxy Counts in the South Galactic Pole Region" Ap.J.494. 111-117 (1998)

  • [Publications] Totani,T.: "Does the Number Density of Elliptical Galaxies Change at z<1?" Ap.J.(Letters). 501. 177-180 (1998)

  • [Publications] Yoshii,Y.: "Age Dating of a High-Redshift QSO B1422+231 at Z=3.62 and Its Cosmological Imprications" Ap.J.(Letters). 507. 113-116 (1998)

  • [Publications] Uchida,G.: "Timelike Infinity and Asymptotic Symmetry" Journ.Math.Phys.39. 6573 (1998)

  • [Publications] Sumiyoshi,K.: "The Fate of a Neutron Star just below the Min-imum Mass:Does It Explode?" Astr.Ap.334. 159 (1998)

  • [Publications] Nagataki,S.: "Supernova Enrichment of Intracluster Medium" Ap.J.504. 629 (1998)

  • [Publications] Kawasaki,M.: "Massive Decaying tau Neutrino and Big Bang Nucleosynthesis" Phys.Lett. B430. 132 (1998)

  • [Publications] Shiromizu,T.: "Generation of Magentic Field due to Excited Q-Balls" Phys.Rev.D58. 107301 (1998)

  • [Publications] Iida,K.: "Effects of Hyperons on the Dynamical Deconfine-ment Transition in Cold Neutron Star Matter" Phys.Rev.C58. 2538-2559 (1998)

  • [Publications] Shiromizu,T.: "Inverse Cascade of Primordial Magnetic Field in MHD Turbulence" Phys.Lett.B443. 127 (1998)

  • [Publications] Hirota,T.: "Abundances of HCN and HNC in Dark Cloud Cores" Ap.J.503. 717-728 (1998)

  • [Publications] Hitota,T.: "Measurements of the 492 GHz Atmospheric Opac-ity at Pampa la Bola and Rio Frio in Northern Chile" Pub.Astron,Soc.Japan. 50. 155-162 (1998)

  • [Publications] Mori,M.: "Dissipative Process as a Mechanism of Differen-tiating Internal Structures between Dwarf and Normal Elliptical Galaxies in a CDM Universe" Ap.J.511. 585-594 (1999)

  • [Publications] Iwamoto,K.: "On the Radio-to-X-Ray Light Curves of SN 1998by and GRB980425" Ap.J.512. L47-L50 (1999)

  • [Publications] Okamura,S.: "Retrieving Bulge and Disk Parmeters and Asymp-totic Magnitudes from the Growth Curves of Galaxies" Publ.Astron.Soc.Pacific. 111. 31-44 (1999)

  • [Publications] W.Buchumuller: "Quark Lepton Mass Hierarchies and The Baryon Asymmetry" Phys.Lett.445. 399-402 (1999)

  • [Publications] Chiba,M.: "New Limits on a Cosmological Constant from Statistics of Gravitational Lensing" Ap.J.510. 42-53 (1999)

  • [Publications] Ikumi,K.: "Freely Falling 2-Surfaces and the Effective Grav-itational Mass" General Relativity and Gravitation. 31. 73 (1999)

  • [Publications] Mskishima,K.: "From the Sun to the Galaxy Clusters(invited)" Observational Plasma Astrophysics:Five Years of Yohkoh and Beyond. 51-60 (1998)

  • [Publications] Mskishima,K.: "Hierarchical Structure in Dark Matter Distribu-tions (invited)" The Hot Universe. 181-184 (1998)

  • [Publications] Tamuma,S.: "Magnetic Recononection as the Origin of Galactic-Ridge X-ray Emission" ibid.269-270 (1998)

  • [Publications] Matsushita,K.: "Solving the Mysteries in Hot ISM in Early-Type Galaxies" ibid.283-284 (1998)

  • [Publications] Mizuno,T.: "X-Ray Observations of the Normal Spiral Galax-ies NGC 2903 and NGC 628" ibid. 284-285 (1998)

  • [Publications] Tashiro,M.: "ASCA X-Ray Observation of the Lobe Dominant Radio Galaxy NGC 612" ibid.289-290 (1998)

  • [Publications] Kubota,A.: "X-Ray Deterrmination of the Black-Hole Mass in Cygnus X-1" ibid. 388-389 (1998)

  • [Publications] Ishisaki,Y.: "Recent Report on the ASCA Gis Source Catalog Project" ibid. 181-184 (1998)

  • [Publications] M.Minowa.: "Cryogenic Dark-Matter and Solar-Axion Searches at the University of Tokyo" International Workshop on Non-Accelerator New Physics(NANP-97). 1117-1119 (1998)

  • [Publications] Nomoto,K.: "X-Rays from Supernova 1993J and Ejecta Insta-bilities" Hot universe. 27-30 (1998)

  • [Publications] Nomoto,k.: "Nucleosynthisis in Type Ia Supernovae and Con-straints on Progenitors" 18th Texas Symposium on Relativistic Astrophysics. 581-584 (1998)

  • [Publications] Umeda,H.: "The C/D Ratio in White Dwarfs and Type Ia supernova:Mass and Metallicity Dependence" Origin of Matter and Evolution of Galaxies 97. 305-312 (1998)

  • [Publications] Young,T.: "Low ^<56>Ni Mass Ejection in Type II Supernovae" Origin of Matter and Evolution of Galaxies 97. 318-326 (1998)

  • [Publications] Kishimoto,N.: "Nucleosynthesis in Delayed Detonation Mass Mod-els for Type Ia Supernovae" Origin of Matter and Evolution of Galaxies 97. 378-381 (1998)

  • [Publications] Kobayashi,C.: "Global Supernova Rate History" Origin of Matter and Evolution of Galaxies 97. 382-385 (1998)

  • [Publications] Nakamura,T.,Iwamoto,K.,Nomoto,K.: "Shock Breakout in SN 1987A and Constraints on the Explosion Energy" Origin of Matter and Evolution of Galaxies 97. 386-389 (1998)

  • [Publications] Saito,R.: "Thermally Stable Model of X-Ray Emitting Gas around Elliptical Galaxies" Origin of Matter and Evolution of Galaxies 97. 390-396 (1998)

  • [Publications] Shimasaku,K.: "Measuring the Density Fluctuation From the Clus-ter Gas Mass Function" Cosmological Parameters and Evolution of the Universe. 120 (1998)

  • [Publications] Yagi,M.: "Type-Specific Luminosity Functions of Nearby Clusters of Galaxies" Cosmological Parameters and Evolution of the Universe. 147 (1998)

  • [Publications] Hanami,H.: "Study of the Shapley Supercluster with ASCA" The Hot Universe. 132 (1998)

  • [Publications] Sekiguchi,M.: "Difference in Luminosity Function within Coma Cluster" Untangling Coma Berenices:A New Vision of an Old Cluster. 87-90 (1998)

  • [Publications] Komiyama,Y.: "Properties of Dwarf Galaxy Population in the Coma Cluster" Untangling Coma Berenices:A New Vision of an Old Cluster. 119-122 (1998)

  • [Publications] Doi,M.: "UT 15-color Dichroic-mirror Camera and Future Prospects" Optical Astronomical Instrumentation. 646-657 (1998)

  • [Publications] Suto,Y.: "Ω_0Δand λ_0Δfrom galaxy and quasar clustering:cosmic virial theorem and cosmological redshift-space distortion" Current Topics in Physics. 734-743 (1998)

  • [Publications] Suto,Y.: "Deternining Ω_0andλ_0 from cosmological red-shift distortion of galaxies and quasars" The Cosmological Parameters and the Evolution of the Universe. 42 (1998)

  • [Publications] Kitayama,T.: "Constraints on the Matter Fluctuatioon Spec-trum from X-Ray Cluster Number Counts" The Cosmological Parameters andthe Evolution of the Universe. 89 (1998)

  • [Publications] Kitayama.T.: "Constraints on the Matter Fluctuatioon Spec-trum from X-Ray Cluster Number Counts" The Hot Universe. 314 (1998)

  • [Publications] Suto,Y.: "Cosmological Implications of X-ray Clusters of Galaxies" Cosmic Microwave Background and Large Scale Struc-ture of the Universe. 33 (1998)

  • [Publications] Suto,Y.: "Cosmological Redshift-Space Distortion of Galax-ies and Quasars at High Redshifts" Cosmic Microwave Background and Large Scale Struc-ture of the Universe. 76 (1998)

  • [Publications] Suginohara,T.: "Detecting the First objects through Their CI and CII Emission" Molecular Hydrogen in the Early Universe. 447-454 (1998)

  • [Publications] Kobayashi,Y.: "MAGNUM(Multicolor Active Galactic Nuclei Monitoring)" Advanced Technology Optical/IR Telescopes VI. 120-128 (1998)

  • [Publications] Yamada,S.: "Modification of Neutrino Reaction Rates in Hot,Dense Metter" the 9th Workshop on "Nuclear Astrophysics". 115 (1998)

URL: 

Published: 1999-12-13   Modified: 2016-04-21  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi