太陽系科学研究系
  1. 研究者リスト
  2. 臼井 寛裕

臼井 寛裕

ウスイ トモヒロ  (Usui Tomohiro)

基本情報

所属
国立研究開発法人宇宙航空研究開発機構 宇宙科学研究所 教授
学位
博士（学術）(岡山大学)
J-GLOBAL ID
201901004664301386
researchmap会員ID
B000348549
外部リンク

Personal HP <https://sites.google.com/site/tomohirousui/>

Google Scholar <https://scholar.google.com/citations?user=iCTuRbUAAAAJ&hl=en>

ISAS astromaterial/curation research group HP <https://curation.isas.jaxa.jp/en/>

研究分野

 1

経歴

 3

論文

 96
  • Fridolin Spitzer, Thorsten Kleine, Christoph Burkhardt, Timo Hopp, Tetsuya Yokoyama, Yoshinari Abe, Jérôme Aléon, Conel M. O’D Alexander, Sachiko Amari, Yuri Amelin, Ken-ichi Bajo, Martin Bizzarro, Audrey Bouvier, Richard W. Carlson, Marc Chaussidon, Byeon-Gak Choi, Nicolas Dauphas, Andrew M. Davis, Tommaso Di Rocco, Wataru Fujiya, Ryota Fukai, Ikshu Gautam, Makiko K. Haba, Yuki Hibiya, Hiroshi Hidaka, Hisashi Homma, Peter Hoppe, Gary R. Huss, Kiyohiro Ichida, Tsuyoshi Iizuka, Trevor R. Ireland, Akira Ishikawa, Shoichi Itoh, Noriyuki Kawasaki, Noriko T. Kita, Kouki Kitajima, Shintaro Komatani, Alexander N. Krot, Ming-Chang Liu, Yuki Masuda, Mayu Morita, Fréderic Moynier, Kazuko Motomura, Izumi Nakai, Kazuhide Nagashima, Ann Nguyen, Larry Nittler, Morihiko Onose, Andreas Pack, Changkun Park, Laurette Piani, Liping Qin, Sara S. Russell, Naoya Sakamoto, Maria Schönbächler, Lauren Tafla, Haolan Tang, Kentaro Terada, Yasuko Terada, Tomohiro Usui, Sohei Wada, Meenakshi Wadhwa, Richard J. Walker, Katsuyuki Yamashita, Qing-Zhu Yin, Shigekazu Yoneda, Edward D. Young, Hiroharu Yui, Ai-Cheng Zhang, Tomoki Nakamura, Hiroshi Naraoka, Takaaki Noguchi, Ryuji Okazaki, Kanako Sakamoto, Hikaru Yabuta, Masanao Abe, Akiko Miyazaki, Aiko Nakato, Masahiro Nishimura, Tatsuaki Okada, Toru Yada, Kasumi Yogata, Satoru Nakazawa, Takanao Saiki, Satoshi Tanaka, Fuyuto Terui, Yuichi Tsuda, Sei-ichiro Watanabe, Makoto Yoshikawa, Shogo Tachibana, Hisayoshi Yurimoto
    Science Advances 10(39) 2024年9月27日  
    The isotopic compositions of samples returned from Cb-type asteroid Ryugu and Ivuna-type (CI) chondrites are distinct from other carbonaceous chondrites, which has led to the suggestion that Ryugu/CI chondrites formed in a different region of the accretion disk, possibly around the orbits of Uranus and Neptune. We show that, like for Fe, Ryugu and CI chondrites also have indistinguishable Ni isotope anomalies, which differ from those of other carbonaceous chondrites. We propose that this unique Fe and Ni isotopic composition reflects different accretion efficiencies of small FeNi metal grains among the carbonaceous chondrite parent bodies. The CI chondrites incorporated these grains more efficiently, possibly because they formed at the end of the disk’s lifetime, when planetesimal formation was also triggered by photoevaporation of the disk. Isotopic variations among carbonaceous chondrites may thus reflect fractionation of distinct dust components from a common reservoir, implying CI chondrites/Ryugu may have formed in the same region of the accretion disk as other carbonaceous chondrites.
  • Alexander B Verchovsky, Feargus A J Abernethy, Mahesh Anand, Ian A Franchi, Monica M Grady, Richard C Greenwood, Simeon J Barber, Martin Suttle, Motoo Ito, Naotaka Tomioka, Masayuki Uesugi, Akira Yamaguchi, Makoto Kimura, Naoya Imae, Naoki Shirai, Takuji Ohigashi, Ming-Chang Liu, Kentaro Uesugi, Aiko Nakato, Kasumi Yogata, Hayato Yuzawa, Yuzuru Karouji, Satoru Nakazawa, Tatsuaki Okada, Takanao Saiki, Satoshi Tanaka, Fuyuto Terui, Makoto Yoshikawa, Akiko Miyazaki, Masahiro Nishimura, Toru Yada, Masanao Abe, Tomohiro Usui, Sen-Ichiro Watanabe, Yuichi Tsuda
    Nature communications 15(1) 8075-8075 2024年9月14日  
    Ryugu is the C-type asteroid from which material was brought to Earth by the Hayabusa2 mission. A number of individual grains and fine-grained samples analysed so far for noble gases have indicated that solar wind and planetary (known as P1) noble gases are present in Ryugu samples with concentrations higher than those observed in CIs, suggesting the former to be more primitive compared to the latter. Here we present results of analyses of three fine-grained samples from Ryugu, in one of which Xe concentration is an order of magnitude higher than determined so far in other samples from Ryugu. Isotopically, this Xe resembles P1, but with a much stronger isotopic fractionation relative to solar wind and significantly lower 36Ar/132Xe ratio than in P1. This previously unknown primordial noble gas component (here termed P7) provides clues to constrain how the solar composition was fractionated to form the planetary components.
  • Larry R Nittler, Jens Barosch, Katherine Burgess, Rhonda M Stroud, Jianhua Wang, Hikaru Yabuta, Yuma Enokido, Megumi Matsumoto, Tomoki Nakamura, Yoko Kebukawa, Shohei Yamashita, Yoshio Takahashi, Laure Bejach, Lydie Bonal, George D Cody, Emmanuel Dartois, Alexandre Dazzi, Bradley De Gregorio, Ariane Deniset-Besseau, Jean Duprat, Cécile Engrand, Minako Hashiguchi, A.L. David Kilcoyne, Mutsumi Komatsu, Zita Martins, Jérémie Mathurin, Gilles Montagnac, Smail Mostefaoui, Taiga Okumura, Eric Quirico, Laurent Remusat, Scott Sandford, Miho Shigenaka, Hiroki Suga, Yasuo Takeichi, Yusuke Tamenori, Maximilien Verdier-Paoletti, Daisuke Wakabayashi, Masanao Abe, Kanami Kamide, Akiko Miyazaki, Aiko Nakato, Satoru Nakazawa, Masahiro Nishimura, Tatsuaki Okada, Takanao Saiki, Satoshi Tanaka, Fuyuto Terui, Tomohiro Usui, Toru Yada, Kasumi Yogata, Makoto Yoshikawa, Hisayoshi Yurimoto, Takaaki Noguchi, Ryuji Okazaki, Hiroshi Naraoka, Kanako Sakamoto, Shogo Tachibana, Sei-ichiro Watanabe, Yuichi Tsuda
    Earth and Planetary Science Letters 637 118719-118719 2024年7月  
  • Yuichiro Ueno, Johan A. Schmidt, Matthew S. Johnson, Xiaofeng Zang, Alexis Gilbert, Hiroyuki Kurokawa, Tomohiro Usui, Shohei Aoki
    Nature Geoscience 2024年5月9日  
    Abstract Organic matter found in early Martian sediment may yield clues to the planet’s environmental conditions, prebiotic chemistry and habitability, but its origin remains unclear. Strong 13C depletion in sedimentary organic matter at Gale crater was recently detected by the Curiosity rover. Although this enigmatic depletion remains debated, if correct, a mechanism to cause such strong 13C depletion is required. Here we show from CO2 photolysis experiments and theoretical considerations that solar ultraviolet photolysis of CO2 in a reducing atmosphere can yield strongly 13C-depleted CO. We suggest that atmospheric synthesis of organic compounds from photolysis-produced CO is a plausible mechanism to explain the source of isotopically depleted organic matter in early Martian sediments. Furthermore, this mechanism could explain 13C enrichment of early Martian CO2 without requiring long-term carbon escape into space. A mass balance model calculation using our estimated isotopic fractionation factor indicates the conversion of approximately 20% of volcanic CO2 emissions on early Mars into organics via CO, consistent with the available data for carbon isotopes of carbonate. Although alternative pathways for organic compound production have been proposed, our findings suggest that considerable amounts of organic matter may have been synthesized from CO in a reducing early Martian atmosphere and deposited in sediments.
  • Ko Hashizume, Akizumi Ishida, Ayano Chiba, Ryuji Okazaki, Kasumi Yogata, Toru Yada, Fumio Kitajima, Hisayoshi Yurimoto, Tomoki Nakamura, Takaaki Noguchi, Hikaru Yabuta, Hiroshi Naraoka, Yoshinori Takano, Kanako Sakamoto, Shogo Tachibana, Masahiro Nishimura, Aiko Nakato, Akiko Miyazaki, Masanao Abe, Tatsuaki Okada, Tomohiro Usui, Makoto Yoshikawa, Takanao Saiki, Fuyuto Terui, Satoshi Tanaka, Satoru Nakazawa, Sei‐ichiro Watanabe, Yuichi Tsuda, Michael W. Broadley, Henner Busemann
    Meteoritics &amp; Planetary Science 2024年4月30日  
    Abstract The nitrogen isotope compositions of two samples returned from the asteroid Ryugu were determined using a stepwise combustion method, along with Ivuna (CI) and Y‐980115, a CI‐like Antarctic meteorite, as references. The two Ryugu samples A0105‐07 and C0106‐07 showed bulk δ15N values of +1.7 ± 0.5‰ and +0.2 ± 0.6‰, respectively, significantly lower than Ivuna with +36.4 ± 0.4‰, but close to Y‐980115 with +4.0 ± 0.3‰. The Ryugu samples are further characterized by C/N and 36Ar/N ratios up to 3.4× and 4.9× the value of Ivuna, respectively. Among all Ryugu samples and CI chondrites, a positive correlation was observed between nitrogen concentrations and δ15N values, with samples with lower nitrogen concentrations exhibiting lower δ15N. This trend is explained by a two‐component mixing model. One component is present at a constant abundance among all CI‐related samples, with a δ15N value around 0‰ or lower. The other varies in abundance between different samples, and exhibits a δ15N value of +56 ± 4‰. The first 15N‐poor endmember is seemingly tightly incorporated into a carbonaceous host phase, whereas the 15N‐rich endmember can be mobilized and decoupled from carbon, potentially because it is in the form of ammonia. Asteroid materials with volatile compositions that are similar to those reported here for the Ryugu samples are attractive candidates for the volatile sources among Earth's building blocks.
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MISC

 28
  • Ryuki Hyodo, Tomohiro Usui
    SCIENCE 373(6556) 742-742 2021年8月  
  • 臼井寛裕, 菅倉春菜, 倉本圭, 倉本圭, 川勝康弘
    宇宙科学技術連合講演会講演集(CD-ROM) 65th 2021年  
  • 吉村義隆, 山岸明彦, 宮川厚夫, 今井栄一, 佐々木聰, 塩谷圭吾, 三田肇, 小林憲正, 癸生川陽子, 佐藤直人, 佐藤毅彦, 薮田ひかる, 長沼毅, 藤田和央, 臼井寛裕
    日本惑星科学会秋季講演会予稿集(Web) 2020 2020年  
  • 臼井寛裕, 関華奈子, 藤田和央
    日本惑星科学会秋季講演会予稿集(Web) 2020 2020年  
  • 鈴木 慧花, 菅 大暉, 山口 亮, 臼井 寛裕, 新田 清文, 関澤 央輝, 高橋 嘉夫
    日本地球化学会年会要旨集 66 177-177 2019年  
    <p>火星隕石ナクライトにはIddingsiteという変質脈が存在し、この中の変質鉱物には火星での水の痕跡が残されている。しかし、変質鉱物には炭酸塩と硫酸塩(jarositeなど)という異なるEh-pH条件で形成したと考えられる物質が共存しており、火星でのIddingsite形成環境・過程は不明瞭である。また、これらの関係性を正確に議論した研究は今までにほとんどない。本研究ではナクライト隕石Y000593のIddingsiteを対象とし、微量元素とその化学種に着目した分析を行った。従来の隕石分析に用いるSEM・EPMA分析に、放射光をベースとしたＸ線顕微分析(μ-XRF-XAFS@BL37XU SPring-8とsemi-μ-XRF-XAFS@BL-15A KEK-PF)から得られる知見を組み合わせることで、変質過程の詳細な解明を試みた。</p>
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共同研究・競争的資金等の研究課題

 10
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