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星と隕石の組成解読を基軸としたr過程元素の起源・進化の解明

Research Project

Project/Area Number 18H01258
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Review Section Basic Section 16010:Astronomy-related
Research InstitutionNational Astronomical Observatory of Japan

Principal Investigator

辻本 拓司  国立天文台, JASMINEプロジェクト, 助教 (10270456)

Co-Investigator(Kenkyū-buntansha) 横山 哲也  東京工業大学, 理学院, 教授 (00467028)
Project Period (FY) 2018-04-01 – 2023-03-31
Project Status Granted (Fiscal Year 2022)
Budget Amount *help
¥17,030,000 (Direct Cost: ¥13,100,000、Indirect Cost: ¥3,930,000)
Fiscal Year 2022: ¥3,380,000 (Direct Cost: ¥2,600,000、Indirect Cost: ¥780,000)
Fiscal Year 2021: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
Fiscal Year 2020: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
Fiscal Year 2019: ¥3,380,000 (Direct Cost: ¥2,600,000、Indirect Cost: ¥780,000)
Fiscal Year 2018: ¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000)
Keywordsr過程元素 / 中性子星合体 / 超新星(強磁場超新星、コラプサー) / 隕石 / 矮小銀河 / 超新星(強磁場超新星、コラプサー) / 重力崩壊型超新星 / ブラックホール / 隕石同位体分析 / radial migration / 球状星団 / 同位体分析 / 強磁場超新星 / 銀河化学力学進化 / 同位体異常
Outline of Annual Research Achievements

星の化学組成解読によるr過程元素解明については、以下の2つの業績を論文として残した。(1). 太陽でのr過程元素の含有量は、太陽近傍星での平均的な値と比べおよそ20-30%程度少ないことを観測的に指摘し、この原因について、太陽系が現在の場所ではなく銀河中心近く(バルジの外側付近)で生まれ、その場所でのバースト的な星形成に付随した化学進化を反映した結果であることを明らかにした。(2). 太陽と化学的物理的特徴が類似した太陽双子星の組成解読の分析結果を化学進化の理論モデルと融合させることから、r過程元素起源天体の同定に成功した。これは太陽双子星の年齢からその星が生まれた場所を同定でき、かつその場所での化学進化を理論的に予測することができるという独自の発想から生まれた手法に基づいたもので、これよりr過程元素の起源天体はこの宇宙に2種類、つまり長寿命の中性子星合体と短寿命の超新星爆発、が存在しなくてはいけないことを明らかにした。また、両者によるr過程元素への貢献度はほぼ同程度であることも突き止め、超新星のr過程への重要性を強調した。

また、分担者横山氏と共にr過程を含む元素合成に関する最新の情報を含む総説を執筆し、Encyclopedia of Geology 2nd editionに公表した。さらに横山氏は、隕石の核合成起源同位体異常を高精度測定するため、単一隕石試料からr過程元素を含む20種類の元素を同時に化学分離する手法を立ち上げるとともに、表面電離型質量分析計(TIMS)を用いて隕石のCr同位体比を超高精度・高確度で測定する新しい手法を開発した。これらの手法を炭素質コンドライトに適用し、隕石のTiおよびCr同位体比の測定結果を地球試料と比較することから、炭素質コンドライトが中性子過剰の環境で形成される50Tiおよび54Crに富むということを確認した。

Current Status of Research Progress
Current Status of Research Progress

2: Research has progressed on the whole more than it was originally planned.

Reason

本研究課題に直接関連する論文として、筆頭著者の論文2本(Tsujimoto & Baba, ApJ; Tsujimoto, ApJL)の掲載を実現したこと、さらに、分担者である横山氏と共にr過程元素を含めた元素の起源に関するレビュー論文 (Yokoyama & Tsujimoto, Encyclopedia of Geology)が受理されたという実績から、順調に進展しているという判断が妥当と思われる。なかでも、単著である論文は、American Astronomical Society (AAS)からハイライト論文の一つに選出されるなど(AAS Nova, 11 Feb. 2022付け)、高い評価を受けている。

Strategy for Future Research Activity

次年度の目標の筆頭に掲げたいものは、銀河系化学進化から宇宙のグローバルな化学進化へ議論を拡張するという独創性に富んだ研究を通して、r過程元素の起源天体の解明に挑むことである。大質量星(太陽質量の8倍以上の星)の最後には、超新星爆発を起こし中性子星を残すか、あるいは爆発を起こすことなくブラックホールを形成するかの2つの運命があるが、近年の観測及び理論研究から、これまでの予想よりもはるかにブラックホールになる確率が高い可能性が指摘されている。この新たな視点を銀河系の化学進化へ導入することから、銀河系星(ディスク星及びバルジ星)の組成解読を行い、中性子星合体頻度の精密な評価及びr過程元素への超新星の寄与を決定していく。さらに、銀河系で得られた知見を宇宙化学進化の議論へと拡張することから、重力崩壊型超新星頻度とブラックホール形成率を赤方偏移の関数として評価を行う方針である。

また、分担者である横山氏は表面電離型質量分析計を用いた隕石の超高精度同位体分析を続行し、前年度までに実施した鉄族元素(Ti, Cr)の同位体分析に加え、r過程元素の同位体分析への挑戦を行う。

このような推進方策を基盤とし、星と隕石の両者からの組成解読を引き続き実行していくことからr過程元素起源全貌に関する描像を構築する。

Report

(3 results)
  • 2020 Annual Research Report
  • 2019 Annual Research Report
  • 2018 Annual Research Report

Research Products

(50 results)

All 2022 2021 2020 2019 2018 Other

All Int'l Joint Research (6 results) Journal Article (17 results) (of which Int'l Joint Research: 5 results,  Peer Reviewed: 17 results,  Open Access: 11 results) Presentation (27 results) (of which Int'l Joint Research: 12 results,  Invited: 10 results)

  • [Int'l Joint Research] 西オーストラリア大学(オーストラリア)

    • Related Report
      2020 Annual Research Report
  • [Int'l Joint Research] ウィーン大学(オーストリア)

    • Related Report
      2020 Annual Research Report
  • [Int'l Joint Research] 西オーストラリア大学(オーストラリア)

    • Related Report
      2019 Annual Research Report
  • [Int'l Joint Research] ウィーン大学(オーストリア)

    • Related Report
      2019 Annual Research Report
  • [Int'l Joint Research] 西オーストラリア大学(オーストラリア)

    • Related Report
      2018 Annual Research Report
  • [Int'l Joint Research] ウィーン大学(オーストリア)

    • Related Report
      2018 Annual Research Report
  • [Journal Article] A Very Metal-poor RR Lyrae Star with a Disk Orbit Found in the Solar Neighborhood2022

    • Author(s)
      Matsunaga Noriyuki、Itane Akinori、Hattori Kohei、Crestani Juliana、Braga Vittorio、Bono Giuseppe、Taniguchi Daisuke、Baba Junichi、Maehara Hiroyuki、Ukita Nobuharu、Sakamoto Tsuyoshi、Kobayashi Naoto、Aoki Tsutomu、Soyano Takao、Tarusawa Ken’ichi、…… 、Tsujimoto Takuji
    • Journal Title

      The Astrophysical Journal

      Volume: 925 Pages: 10-10

    • DOI

      10.3847/1538-4357/ac3483

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Chemical and Isotopic Evaluation of a Microsampling Method using Laser Ablation and Membrane Filter2022

    • Author(s)
      Masuda Yuki、Yokoyama Tetsuya、Okabayashi Satoki、Ishikawa Akira、Iwamori Hikaru
    • Journal Title

      Geostandards and Geoanalytical Research

      Volume: -

    • DOI

      10.1111/ggr.12426

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Geochemical constraints on the formation of chondrules: Implication from Os and Fe isotopes and HSE abundances in metals from CR chondrites2022

    • Author(s)
      Nakanishi Nao、Yokoyama Tetsuya、Okabayashi Satoki、Iwamori Hikaru、Hirata Takafumi
    • Journal Title

      Geochimica et Cosmochimica Acta

      Volume: 319 Pages: 254-270

    • DOI

      10.1016/j.gca.2021.11.009

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Nucleosynthesis: The Where and How2021

    • Author(s)
      Yokoyama Tetsuya、Tsujimoto Takuji
    • Journal Title

      Encyclopedia of Geology 2nd edition

      Volume: 5 Pages: 1-19

    • DOI

      10.1016/b978-0-08-102908-4.00121-1

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Absorption Lines in the 0.91-1.33 μm Spectra of Red Giants for Measuring Abundances of Mg, Si, Ca, Ti, Cr, and Ni2021

    • Author(s)
      Fukue Kei、Matsunaga Noriyuki、Kondo Sohei、Taniguchi Daisuke、Ikeda Yuji、Kobayashi Naoto、Sameshima Hiroaki、Hamano Satoshi、Arai Akira、Kawakita Hideyo、Yasui Chikako、Mizumoto Misaki、Otsubo Shogo、Takenaka Keiichi、Yoshikawa Tomohiro、Tsujimoto Takuji
    • Journal Title

      The Astrophysical Journal

      Volume: 913 Pages: 62-62

    • DOI

      10.3847/1538-4357/abf0b1

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] Two Sites of r-process Production Assessed on the Basis of the Age-tagged Abundances of Solar Twins2021

    • Author(s)
      Tsujimoto Takuji
    • Journal Title

      The Astrophysical Journal Letters

      Volume: 920

    • DOI

      10.3847/2041-8213/ac2c75

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] Variable refractory lithophile element compositions of planetary building blocks: Insights from components of enstatite chondrites2021

    • Author(s)
      Yoshizaki Takashi、Ash Richard D.、Lipella Marc D.、Yokoyama Tetsuya、McDonough William F.
    • Journal Title

      Geochimica et Cosmochimica Acta

      Volume: 308 Pages: 173-187

    • DOI

      10.1016/j.gca.2021.05.057

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Remarkable Migration of the Solar System from the Innermost Galactic Disk; a Wander, a Wobble, and a Climate Catastrophe on the Earth2020

    • Author(s)
      Tsujimoto Takuji、Baba Junichi
    • Journal Title

      The Astrophysical Journal

      Volume: 904 Pages: 137-137

    • DOI

      10.3847/1538-4357/abc00a

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] Identification of Absorption Lines of Heavy Metals in the Wavelength Range 0.97-1.32 μm2020

    • Author(s)
      Matsunaga Noriyuki、Taniguchi Daisuke、Jian Mingjie、Ikeda Yuji、Fukue Kei、Kondo Sohei、Hamano Satoshi、Kawakita Hideyo、Kobayashi Naoto、Otsubo Shogo、Sameshima Hiroaki、Takenaka Keiichi、Tsujimoto Takuji、Watase Ayaka、Yasui Chikako、Yoshikawa Tomohiro
    • Journal Title

      The Astrophysical Journal Supplement Series

      Volume: 246 Pages: 10-10

    • DOI

      10.3847/1538-4365/ab5c25

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] r-process enrichment in the Galactic halo characterized by nucleosynthesis variation in the ejecta of coalescing neutron star binaries2020

    • Author(s)
      Takuji Tsujimoto, Nobuya Nishimura, Koutarou Kyutoku
    • Journal Title

      The Astrophysical Journal

      Volume: 889 Pages: 119-119

    • DOI

      10.3847/1538-4357/ab655c

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] Separation of Heavy Lanthanoids by Flash Column Chromatography for Precise Determination of Er and Yb Isotope Compositions in Rock Samples2020

    • Author(s)
      Yokoyama Tetsuya、Fukai Ryota、Nakahara Masaki
    • Journal Title

      Geostandards and Geoanalytical Research

      Volume: in press Pages: 265-285

    • DOI

      10.1111/ggr.12317

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Galactic r-process Abundance Feature Shaped by Radial Migration2019

    • Author(s)
      Tsujimoto, Takuji; Baba, Junichi
    • Journal Title

      The Astrophysical Journal

      Volume: 878 Pages: 125-125

    • DOI

      10.3847/1538-4357/ab22b3

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] A New Formation Model for ω Centauri: A Complex Interplay of Astrophysical Processes2019

    • Author(s)
      Bekki Kenji、Tsujimoto Takuji
    • Journal Title

      The Astrophysical Journal

      Volume: 886 Pages: 121-121

    • DOI

      10.3847/1538-4357/ab464d

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Origin and Evolution of Distinct Molybdenum Isotopic Variabilities within Carbonaceous and Noncarbonaceous Reservoirs2019

    • Author(s)
      Yokoyama Tetsuya、Nagai Yuichiro、Fukai Ryota、Hirata Takafumi
    • Journal Title

      The Astrophysical Journal

      Volume: 883 Pages: 62-62

    • DOI

      10.3847/1538-4357/ab39e7

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] FeI lines in 0.91-1.33 micrometre spectra of red giants for measuring the microturbulence and metallicities2019

    • Author(s)
      Kondo S.、Fukue K.、Matsunaga N.、et al.
    • Journal Title

      The Astrophysical Journal

      Volume: in press

    • Related Report
      2018 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Nucleosynthetic Sr-Nd isotope correlation in chondrites: Evidence for nebular thermal processing and dust transportation in the early Solar System2019

    • Author(s)
      Fukai R.、 Yokoyama T.
    • Journal Title

      The Astrophysical Journal

      Volume: in press

    • Related Report
      2018 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Early Chemical Evolution of Zn Driven by Magnetorotational Supernovae and the Pathway to the Solar Zn Composition2018

    • Author(s)
      Tsujimoto Takuji、Nishimura Nobuya
    • Journal Title

      The Astrophysical Journal

      Volume: 863

    • DOI

      10.3847/2041-8213/aad86b

    • Related Report
      2018 Annual Research Report
    • Peer Reviewed / Open Access
  • [Presentation] 超新星由来のr過程元素を強く示唆する銀河系化学進化2022

    • Author(s)
      辻本拓司
    • Organizer
      新学術「地下宇宙」第8回超新星ニュートリノ研究会
    • Related Report
      2020 Annual Research Report
  • [Presentation] Origin of nucleosynthetic Sr isotope anomalies in fine grained calcium and aluminum-rich inclusions from Allende2022

    • Author(s)
      Masuda, Y., Yokoyama, T.
    • Organizer
      Lunar and Planetary Science Conference, The Woodlands, USA
    • Related Report
      2020 Annual Research Report
    • Int'l Joint Research
  • [Presentation] 太陽系の銀河内軌道変化と地球の寒冷化2021

    • Author(s)
      辻本拓司
    • Organizer
      新学術「地下宇宙」第7回超新星ニュートリノ研究会
    • Related Report
      2020 Annual Research Report
  • [Presentation] Allende隕石中細粒CAIに見られる核合成起源のSr同位体異常の多様性2021

    • Author(s)
      増田雄樹、横山哲也
    • Organizer
      日本地球化学会2021年会
    • Related Report
      2020 Annual Research Report
  • [Presentation] 高精度Nd同位体比測定による平衡論的同位体効果の同定2021

    • Author(s)
      深井稜汰, 若木重行, 横山哲也
    • Organizer
      日本地球化学会2021年会
    • Related Report
      2020 Annual Research Report
  • [Presentation] 近赤外線高分散分光器WINERED : Mg, Si, Ca, Ti, Cr, Niの化学組成導出に用いるYJバンド中の吸収線の選定2020

    • Author(s)
      福江慧、池田優二、河北秀世、松永典之、近藤荘平、谷口大輔、鮫島寛明、小林尚人、濱野哲史、安井千香子、辻本拓司、WINERED開発チーム
    • Organizer
      日本天文学会秋季年会
    • Related Report
      2020 Annual Research Report
  • [Presentation] 太陽系大移動と地球の寒冷化2020

    • Author(s)
      辻本拓司
    • Organizer
      京都大学地球惑星科学セミナー
    • Related Report
      2020 Annual Research Report
    • Invited
  • [Presentation] Origin and evolution of distinct isotopic variabilities for Sr, Mo, and Nd within inner and outer solar system2020

    • Author(s)
      Yokoyama, T., Fukai, R., Nagai, Y., Hirata, T.
    • Organizer
      JpGU-AGU Joint meeting
    • Related Report
      2020 Annual Research Report
  • [Presentation] Origin and evolution of distinct isotopic variabilities for Sr, Mo, and Nd within CC and NC reservoirs (Keynote Talk)2020

    • Author(s)
      Yokoyama, T., Fukai, R., Nagai, Y., Hirata, T.
    • Organizer
      Goldschmidt Conference
    • Related Report
      2020 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] 隕石の重元素同位体異常にまつわる最近の話題2020

    • Author(s)
      横山哲也
    • Organizer
      研究会「星の錬金術から銀河考古学へ」
    • Related Report
      2020 Annual Research Report
    • Invited
  • [Presentation] Recent progress in the application of nucleosynthetic isotope anomalies in meteorites2020

    • Author(s)
      Yokoyama, T.
    • Organizer
      ISAS Colloquium
    • Related Report
      2020 Annual Research Report
    • Invited
  • [Presentation] 理論からの宇宙化学進化2019

    • Author(s)
      辻本拓司
    • Organizer
      第6回超新星ニュートリノ天文学
    • Related Report
      2019 Annual Research Report
    • Invited
  • [Presentation] Connection of r-process enrichment with the gravitational-wave detection rate2019

    • Author(s)
      Tsujimoto, T.
    • Organizer
      Gravitational wave physics and astronomy: Genesis, Third Annual Symposium
    • Related Report
      2019 Annual Research Report
    • Int'l Joint Research
  • [Presentation] 近赤外線YJバンドに存在するCuより重い元素の吸収線の同定2019

    • Author(s)
      松永典之、谷口大輔、Mingjie Jian、近藤荘平、小林尚人、鮫島寛明、池田優二、福江慧、河北 秀世、大坪翔悟、竹中慶一、渡瀬彩華、吉川智裕、濱野哲史、辻本拓司、安井千香子
    • Organizer
      日本天文学会春季年会
    • Related Report
      2019 Annual Research Report
  • [Presentation] Nucleosynthetic Sr and Nd isotopic anomalies of bulk differentiated meteorites2019

    • Author(s)
      Fukai, R., Sugimoto, K., Yokoyama, T.
    • Organizer
      Goldschmidt Conference
    • Related Report
      2019 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Separation of heavy lanthanoids by flash column chromatography for precise determination of Er and Yb isotope compositions in rock samples2019

    • Author(s)
      Yokoyama, T.
    • Organizer
      4th China-Japan Joint Forum on Geochemistry and Cosmochemistry
    • Related Report
      2019 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] Nucleosynthetic Sr and Nd isotopic anomalies of bulk differentiated meteorites2019

    • Author(s)
      Fukai, R., Sugimoto, K., Yokoyama, T.
    • Organizer
      JpGU 2019
    • Related Report
      2019 Annual Research Report
  • [Presentation] 宇宙化学進化とニュートリノ天文学2019

    • Author(s)
      辻本拓司
    • Organizer
      第5回超新星ニュートリノ研究会
    • Related Report
      2018 Annual Research Report
    • Invited
  • [Presentation] Molybdenum isotopic evidence for nebular thermal processing and material transportation in the inner solar system2019

    • Author(s)
      Yokoyama T.、 Fukai R.、 Tsujimoto T.
    • Organizer
      Lunar and Planetary Science Conference
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Nucleosynthetic strontium-neodymium isotope correlation in chondrites: Evidence for nebular thermal processing and dust transportation in the early solar system2019

    • Author(s)
      Fukai R.、 Yokoyama T.
    • Organizer
      Lunar and Planetary Science Conference
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research
  • [Presentation] 希土類元素創生:2018年宇宙の旅2018

    • Author(s)
      辻本拓司
    • Organizer
      日本希土類学会
    • Related Report
      2018 Annual Research Report
    • Invited
  • [Presentation] r-process study based on stellar abundances and meteorites2018

    • Author(s)
      Takuji Tsujimoto
    • Organizer
      Gravitational wave physics and astronomy: Genesis, Area Workshop
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Sporadic r-process events found in the Draco dwarf spheroidal galaxy2018

    • Author(s)
      Takuji Tsujimoto
    • Organizer
      IAU Symposium 344: Dwarf Galaxies: From the Deep Universe to the Present
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research
  • [Presentation] r-process nucleosynthesis and enrichment2018

    • Author(s)
      Takuji Tsujimoto
    • Organizer
      Gravitational wave physics and astronomy: Genesis, Second Annual Symposium
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research
  • [Presentation] 星と隕石の化学組成に刻まれたr過程元素の起源と進化2018

    • Author(s)
      辻本拓司
    • Organizer
      重力波観測時代のrプロセスと不安定核
    • Related Report
      2018 Annual Research Report
    • Invited
  • [Presentation] Meteoritical perspective on the origin of r-process nuclides in the Solar System2018

    • Author(s)
      Yokoyama T.、 Fukai R.、 Tsujimoto T.
    • Organizer
      3rd Korea-Japan Joint Workshop on Isotope-Ratio Mass Spectrometry
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] Nucleosynthetic Sr-;Nd correlation in bulk chondrites: Evidence for nebular thermal processing and transportation of refractory dusts in the early Solar System2018

    • Author(s)
      Fukai R.、 Yokoyama T.
    • Organizer
      Goldschmidt Conference
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research

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Published: 2018-04-23   Modified: 2022-12-28  

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