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197 results on '"Yamashita, Katsuyuki"'

1. The Ni isotopic composition of Ryugu reveals a common accretion region for carbonaceous chondrites

Author

Spitzer, Fridolin, Kleine, Thorsten, Burkhardt, Christoph, Hopp, Timo, Yokoyama, Tetsuya, Abe, Yoshinari, Aléon, Jérôme, Alexander, Conel M. O'D., Amari, Sachiko, Amelin, Yuri, Bajo, Ken-ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard W., Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew M., Di Rocco, Tommaso, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary R., Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko T., Kitajima, Kouki, Komatani, Shintaro, Krot, Alexander N., Liu, Ming-Chang, Masuda, Yuki, Morita, Mayu, Moynier, Fréderic, Motomura, Kazuko, Nakai, Izumi, Nagashima, Kazuhide, Nguyen, Ann, Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Russell, Sara S., Sakamoto, Naoya, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard J., Yamashita, Katsuyuki, Yin, Qing-Zhu, Yoneda, Shigekazu, Young, Edward D., Yui, Hiroharu, Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-ichiro, Yoshikawa, Makoto, Tachibana, Shogo, and Yurimoto, Hisayoshi

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

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 and 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 and Ryugu may have formed in the same region of the accretion disk as other carbonaceous chondrites., Comment: Published open access in Science Advances

Published
2024
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2. Water circulation in Ryugu asteroid affected the distribution of nucleosynthetic isotope anomalies in returned sample.

Author

Yokoyama, Tetsuya, Wadhwa, Meenakshi, Iizuka, Tsuyoshi, Rai, Vinai, Gautam, Ikshu, Hibiya, Yuki, Masuda, Yuki, Haba, Makiko, Fukai, Ryota, Hines, Rebekah, Phelan, Nicole, Abe, Yoshinari, Aléon, Jérôme, Alexander, Conel, Amari, Sachiko, Amelin, Yuri, Bajo, Ken-Ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard, Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew, Di Rocco, Tommaso, Fujiya, Wataru, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary, Ichida, Kiyohiro, Ireland, Trevor, Ishikawa, Akira, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko, Kitajima, Koki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander, Liu, Ming-Chang, McKeegan, Kevin, Morita, Mayu, Motomura, Kazuko, Moynier, Frédéric, Nakai, Izumi, Nagashima, Kazuhide, Nguyen, Ann, Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Russell, Sara, Sakamoto, Naoya, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wada, Sohei, Walker, Richard, Yamashita, Katsuyuki, Yoneda, Shigekazu, Young, Edward, Yui, Hiroharu, Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-Ichiro, Yoshikawa, Makoto, Tachibana, Shogo, Yurimoto, Hisayoshi, and Yin, Qing-Zhu

Abstract

Studies of material returned from Cb asteroid Ryugu have revealed considerable mineralogical and chemical heterogeneity, stemming primarily from brecciation and aqueous alteration. Isotopic anomalies could have also been affected by delivery of exogenous clasts and aqueous mobilization of soluble elements. Here, we show that isotopic anomalies for mildly soluble Cr are highly variable in Ryugu and CI chondrites, whereas those of Ti are relatively uniform. This variation in Cr isotope ratios is most likely due to physicochemical fractionation between 54Cr-rich presolar nanoparticles and Cr-bearing secondary minerals at the millimeter-scale in the bulk samples, likely due to extensive aqueous alteration in their parent bodies that occurred [Formula: see text] after Solar System birth. In contrast, Ti isotopes were marginally affected by this process. Our results show that isotopic heterogeneities in asteroids are not all nebular or accretionary in nature but can also reflect element redistribution by water.

Published
2023

3. Abundant presolar grains and primordial organics preserved in carbon-rich exogenous clasts in asteroid Ryugu.

Author

Nguyen, Ann, Mane, Prajkta, Keller, Lindsay, Piani, Laurette, Abe, Yoshinari, Aléon, Jérôme, Alexander, Conel, Amari, Sachiko, Amelin, Yuri, Bajo, Ken-Ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard, Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew, Di Rocco, Tommaso, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko, Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary, Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor, Ishikawa, Akira, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko, Kitajima, Kouki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander, Liu, Ming-Chang, Masuda, Yuki, McKeegan, Kevin, Morita, Mayu, Motomura, Kazuko, Moynier, Frédéric, Nakai, Izumi, Nagashima, Kazuhide, Nesvorný, David, Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Qin, Liping, Russell, Sara, Sakamoto, Naoya, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard, Yamashita, Katsuyuki, Yokoyama, Tetsuya, Yoneda, Shigekazu, Young, Edward, Yui, Hiroharu, Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-Ichiro, Yoshikawa, Makoto, Tachibana, Shogo, Yurimoto, Hisayoshi, and Yin, Qing-Zhu

Subjects
Carbon, Solar System, Meteoroids, Silicates
Abstract

Preliminary analyses of asteroid Ryugu samples show kinship to aqueously altered CI (Ivuna-type) chondrites, suggesting similar origins. We report identification of C-rich, particularly primitive clasts in Ryugu samples that contain preserved presolar silicate grains and exceptional abundances of presolar SiC and isotopically anomalous organic matter. The high presolar silicate abundance (104 ppm) indicates that the clast escaped extensive alteration. The 5 to 10 times higher abundances of presolar SiC (~235 ppm), N-rich organic matter, organics with N isotopic anomalies (1.2%), and organics with C isotopic anomalies (0.2%) in the primitive clasts compared to bulk Ryugu suggest that the clasts formed in a unique part of the protoplanetary disk enriched in presolar materials. These clasts likely represent previously unsampled outer solar system material that accreted onto Ryugu after aqueous alteration ceased, consistent with Ryugus rubble pile origin.

Published
2023

4. Presolar stardust in asteroid Ryugu

Author

Barosch, Jens, Nittler, Larry R., Wang, Jianhua, Alexander, Conel M. O'D., De Gregorio, Bradley T., Engrand, Cécile, Kebukawa, Yoko, Nagashima, Kazuhide, Stroud, Rhonda M., Yabuta, Hikaru, Abe, Yoshinari, Aléon, Jérôme, Amari, Sachiko, Amelin, Yuri, Bajo, Ken-ichi, Bejach, Laure, Bizzarro, Martin, Bonal, Lydie, Bouvier, Audrey, Carlson, Richard W., Chaussidon, Marc, Choi, Byeon-Gak, Cody, George D., Dartois, Emmanuel, Dauphas, Nicolas, Davis, Andrew M., Dazzi, Alexandre, Deniset-Besseau, Ariane, Di Rocco, Tommaso, Duprat, Jean, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hashiguchi, Minako, Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary R., Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Ito, Motoo, Itoh, Shoichi, Kamide, Kanami, Kawasaki, Noriyuki, Kilcoyne, A. L. David, Kita, Noriko T., Kitajima, Kouki, Kleine, Thorsten, Komatani, Shintaro, Komatsu, Mutsumi, Krot, Alexander N., Liu, Ming-Chang, Martins, Zita, Masuda, Yuki, Mathurin, Jérémie, McKeegan, Kevin D., Montagnac, Gilles, Morita, Mayu, Mostefaoui, Smail, Motomura, Kazuko, Moynier, Frédéric, Nakai, Izumi, Nguyen, Ann N., Ohigashi, Takuji, Okumura, Taiga, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Quirico, Eric, Remusat, Laurent, Russell, Sara S., Sakamoto, Naoya, Sandford, Scott A., Schönbächler, Maria, Shigenaka, Miho, Suga, Hiroki, Tafla, Lauren, Takahashi, Yoshio, Takeichi, Yasuo, Tamenori, Yusuke, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Verdier-Paoletti, Maximilien, Wada, Sohei, Wadhwa, Meenakshi, Wakabayashi, Daisuke, Walker, Richard J., Yamashita, Katsuyuki, Yamashita, Shohei, Yin, Qing-Zhu, Yokoyama, Tetsuya, Yoneda, Shigekazu, Young, Edward D., Yui, Hiroharu, Zhang, Ai-Cheng, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nakazawa, Satoru, Nishimura, Masahiro, Okada, Tatsuaki, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-ichiro, Yada, Toru, Yogata, Kasumi, Yoshikawa, Makoto, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Tachibana, Shogo, and Yurimoto, Hisayoshi

Subjects
Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Solar and Stellar Astrophysics
Abstract

We have conducted a NanoSIMS-based search for presolar material in samples recently returned from C-type asteroid Ryugu as part of JAXA's Hayabusa2 mission. We report the detection of all major presolar grain types with O- and C-anomalous isotopic compositions typically identified in carbonaceous chondrite meteorites: 1 silicate, 1 oxide, 1 O-anomalous supernova grain of ambiguous phase, 38 SiC, and 16 carbonaceous grains. At least two of the carbonaceous grains are presolar graphites, whereas several grains with moderate C isotopic anomalies are probably organics. The presolar silicate was located in a clast with a less altered lithology than the typical extensively aqueously altered Ryugu matrix. The matrix-normalized presolar grain abundances in Ryugu are 4.8$^{+4.7}_{-2.6}$ ppm for O-anomalous grains, 25$^{+6}_{-5}$ ppm for SiC grains and 11$^{+5}_{-3}$ ppm for carbonaceous grains. Ryugu is isotopically and petrologically similar to carbonaceous Ivuna-type (CI) chondrites. To compare the in situ presolar grain abundances of Ryugu with CI chondrites, we also mapped Ivuna and Orgueil samples and found a total of SiC grains and 6 carbonaceous grains. No O-anomalous grains were detected. The matrix-normalized presolar grain abundances in the CI chondrites are similar to those in Ryugu: 23 $^{+7}_{-6}$ ppm SiC and 9.0$^{+5.3}_{-4.6}$ ppm carbonaceous grains. Thus, our results provide further evidence in support of the Ryugu-CI connection. They also reveal intriguing hints of small-scale heterogeneities in the Ryugu samples, such as locally distinct degrees of alteration that allowed the preservation of delicate presolar material., Comment: 12 pages, 3 figures, 2 tables. Published in ApJL

Published
2022
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5. Oxygen isotopes of anhydrous primary minerals show kinship between asteroid Ryugu and comet 81P/Wild2

Author

Kawasaki, Noriyuki, Nagashima, Kazuhide, Sakamoto, Naoya, Matsumoto, Toru, Bajo, Ken-ichi, Wada, Sohei, Igami, Yohei, Miyake, Akira, Noguchi, Takaaki, Yamamoto, Daiki, Russell, Sara S, Abe, Yoshinari, Aléon, Jérôme, Alexander, Conel M O’D, Amari, Sachiko, Amelin, Yuri, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard W, Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew M, Di Rocco, Tommaso, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K, Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary R, Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor R, Ishikawa, Akira, Ito, Motoo, Itoh, Shoichi, Kita, Noriko T, Kitajima, Kouki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander N, Liu, Ming-Chang, Masuda, Yuki, McKeegan, Kevin D, Morita, Mayu, Motomura, Kazuko, Moynier, Frédéric, Nakai, Izumi, Nguyen, Ann, Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wadhwa, Meenakshi, Walker, Richard J, Yamashita, Katsuyuki, Yin, Qing-Zhu, Yokoyama, Tetsuya, Yoneda, Shigekazu, Young, Edward D, Yui, Hiroharu, Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-ichiro, Yoshikawa, Makoto, Tachibana, Shogo, and Yurimoto, Hisayoshi

Subjects
Earth Sciences, Physical Sciences, Space Sciences, Geology, Prevention
Abstract

The extraterrestrial materials returned from asteroid (162173) Ryugu consist predominantly of low-temperature aqueously formed secondary minerals and are chemically and mineralogically similar to CI (Ivuna-type) carbonaceous chondrites. Here, we show that high-temperature anhydrous primary minerals in Ryugu and CI chondrites exhibit a bimodal distribution of oxygen isotopic compositions: 16O-rich (associated with refractory inclusions) and 16O-poor (associated with chondrules). Both the 16O-rich and 16O-poor minerals probably formed in the inner solar protoplanetary disk and were subsequently transported outward. The abundance ratios of the 16O-rich to 16O-poor minerals in Ryugu and CI chondrites are higher than in other carbonaceous chondrite groups but are similar to that of comet 81P/Wild2, suggesting that Ryugu and CI chondrites accreted in the outer Solar System closer to the accretion region of comets.

Published
2022

6. Ryugus nucleosynthetic heritage from the outskirts of the Solar System.

Author

Hopp, Timo, Dauphas, Nicolas, Abe, Yoshinari, Aléon, Jérôme, OD Alexander, Conel, Amari, Sachiko, Amelin, Yuri, Bajo, Ken-Ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard, Chaussidon, Marc, Choi, Byeon-Gak, Davis, Andrew, Di Rocco, Tommaso, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko, Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary, Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor, Ishikawa, Akira, Ito, Motoo, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko, Kitajima, Kouki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander, Liu, Ming-Chang, Masuda, Yuki, McKeegan, Kevin, Morita, Mayu, Motomura, Kazuko, Moynier, Frédéric, Nakai, Izumi, Nagashima, Kazuhide, Nesvorný, David, Nguyen, Ann, Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Russell, Sara, Sakamoto, Naoya, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard, Yamashita, Katsuyuki, Yin, Qing-Zhu, Yokoyama, Tetsuya, Yoneda, Shigekazu, Young, Edward, Yui, Hiroharu, Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-Ichiro, Yoshikawa, Makoto, Tachibana, Shogo, and Yurimoto, Hisayoshi

Abstract

Little is known about the origin of the spectral diversity of asteroids and what it says about conditions in the protoplanetary disk. Here, we show that samples returned from Cb-type asteroid Ryugu have Fe isotopic anomalies indistinguishable from Ivuna-type (CI) chondrites, which are distinct from all other carbonaceous chondrites. Iron isotopes, therefore, demonstrate that Ryugu and CI chondrites formed in a reservoir that was different from the source regions of other carbonaceous asteroids. Growth and migration of the giant planets destabilized nearby planetesimals and ejected some inward to be implanted into the Main Belt. In this framework, most carbonaceous chondrites may have originated from regions around the birthplaces of Jupiter and Saturn, while the distinct isotopic composition of CI chondrites and Ryugu may reflect their formation further away in the disk, owing their presence in the inner Solar System to excitation by Uranus and Neptune.

Published
2022

7. Pyrrhotites in asteroid 162173 Ryugu: Records of the initial changes on their surfaces with aqueous alteration

Author

Yui, Hiroharu, Urashima, Shu-hei, Onose, Morihiko, Morita, Mayu, Komatani, Shintaro, Nakai, Izumi, Abe, Yoshinari, Terada, Yasuko, Homma, Hisashi, Motomura, Kazuko, Ichida, Kiyohiro, Yokoyama, Tetsuya, Nagashima, Kazuhide, Aléon, Jérôme, M. O’D. Alexander, Conel, Amari, Sachiko, Amelin, Yuri, Bajo, Ken-ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard W., Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew M., Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hibiya, Yuki, Hidaka, Hiroshi, Hoppe, Peter, Huss, Gary R., Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko T., Kitajima, Kouki, Kleine, Thorsten, Krot, Sasha, Liu, Ming-Chang, Masuda, Yuki, Moynier, Frédéric, Nguyen, Ann, Nittler, Larry, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Di Rocco, Tommaso, Russell, Sara S., Sakamoto, Naoya, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard J., Yamashita, Katsuyuki, Yin, Qing-Zhu, Yoneda, Shigekazu, Young, Edward D., Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-ichiro, Yoshikawa, Makoto, Tachibana, Shogo, and Yurimoto, Hisayoshi

Published
2024
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8. Pervasive aqueous alteration in the early Solar System revealed by potassium isotopic variations in Ryugu samples and carbonaceous chondrites

Author

Hu, Yan, Moynier, Frédéric, Dai, Wei, Paquet, Marine, Yokoyama, Tetsuya, Abe, Yoshinari, Aléon, Jérôme, Alexander, Conel M. O'D., Amari, Sachiko, Amelin, Yuri, Bajo, Ken-ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard W., Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew M., Di Rocco, Tommaso, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary R., Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko T., Kitajima, Koki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander N., Liu, Ming-Chang, Masuda, Yuki, Morita, Mayu, Motomura, Kazuko, Nakai, Izumi, Nagashima, Kazuhide, Nesvorný, David, Nguyen, Ann, Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Russell, Sara S., Sakamoto, Naoya, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard J., Yamashita, Katsuyuki, Yin, Qing-Zhu, Yoneda, Shigekazu, Young, Edward D., Yui, Hiroharu, Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-ichiro, Yoshikawa, Makoto, Tachibana, Shogo, and Yurimoto, Hisayoshi

Published
2024
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9. Contribution of Ryugu-like material to Earth’s volatile inventory by Cu and Zn isotopic analysis

Author

Paquet, Marine, Moynier, Frederic, Yokoyama, Tetsuya, Dai, Wei, Hu, Yan, Abe, Yoshinari, Aléon, Jérôme, O’D. Alexander, Conel M., Amari, Sachiko, Amelin, Yuri, Bajo, Ken-ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard W., Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew M., Di Rocco, Tommaso, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary R., Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Ito, Motoo, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko T., Kitajima, Kouki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander N., Liu, Ming-Chang, Masuda, Yuki, McKeegan, Kevin D., Morita, Mayu, Motomura, Kazuko, Nakai, Izumi, Nagashima, Kazuhide, Nesvorný, David, Nguyen, Ann N., Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Russell, Sara S., Sakamoto, Naoya, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard J., Yamashita, Katsuyuki, Yin, Qing-Zhu, Yoneda, Shigekazu, Young, Edward D., Yui, Hiroharu, Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-ichiro, Yoshikawa, Makoto, Tachibana, Shogo, and Yurimoto, Hisayoshi

Published
2023
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10. Multiple Diffusion-Freezing Mechanisms in Molecular Hydrogen Films

Author

Makiuchi, Takahiko, Yamashita, Katsuyuki, Tagai, Michihiro, Nago, Yusuke, and Shirahama, Keiya

Subjects
Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

Molecular hydrogen is a fascinating candidate for quantum fluid showing bosonic and fermionic superfluidity. We have studied diffusion dynamics of thin films of H$_2$, HD and D$_2$ adsorbed on a glass substrate by measurements of elasticity. The elasticity shows multiple anomalies well below bulk triple point. They are attributed to three different diffusion mechanisms of admolecules and their "freezing" into localized state: classical thermal diffusion of vacancies, quantum tunneling of vacancies, and diffusion of molecules in the uppermost surface. The surface diffusion is active down to 1 K, below which the molecules become localized. This suggests that the surface layer of hydrogen films is on the verge of quantum phase transition to superfluid state., Comment: 5 pages, 3 figures

Published
2019
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11. Elastic Anomaly of Thin Neon Film

Author

Makiuchi, Takahiko, Yamashita, Katsuyuki, Tagai, Michihiro, Nago, Yusuke, and Shirahama, Keiya

Subjects
Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

Adsorbed molecular films provide two-dimensional systems that show various emergent phenomena that are not observed in bulk counterparts. We have measured the elasticity of thin neon films adsorbed on porous glass down to 1 K by the torsional oscillator technique. The shear modulus of a neon film anomalously increases at low temperatures with excess dissipation. This behavior indicates a crossover from a soft (fluidlike) state at high temperatures to a stiff (solidlike) state at low temperatures. The temperature dependence of the anomaly is qualitatively similar to that of the elastic anomaly of helium films found in our recent study. The dissipation peak temperature, however, becomes constant at about 5 K, contrary to the case of helium, in which it decreases to 0 K at a critical coverage of a quantum phase transition between a gapped localized phase and a mobile (superfluid) phase. It is concluded that neon films behave as a classical system that does not show a quantum phase transition or superfluidity, although the films may be strongly supercooled to temperatures much lower than the bulk triple point, 24.6 K. Our results suggest that the elastic anomaly is a universal phenomenon of atomic or molecular films adsorbed on disordered substrates., Comment: 7 pages, 6 figures

Published
2019
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12. Chondrules reveal large-scale outward transport of inner Solar System materials in the protoplanetary disk

Author

Williams, Curtis D, Sanborn, Matthew E, Defouilloy, Céline, Yin, Qing-Zhu, Kita, Noriko T, Ebel, Denton S, Yamakawa, Akane, and Yamashita, Katsuyuki

Subjects
Earth Sciences, Physical Sciences, Space Sciences, Geology, chondrules, bulk meteorites, isotope anomalies, disk transport, disk mixing
Abstract

Dynamic models of the protoplanetary disk indicate there should be large-scale material transport in and out of the inner Solar System, but direct evidence for such transport is scarce. Here we show that the ε50Ti-ε54Cr-Δ17O systematics of large individual chondrules, which typically formed 2 to 3 My after the formation of the first solids in the Solar System, indicate certain meteorites (CV and CK chondrites) that formed in the outer Solar System accreted an assortment of both inner and outer Solar System materials, as well as material previously unidentified through the analysis of bulk meteorites. Mixing with primordial refractory components reveals a "missing reservoir" that bridges the gap between inner and outer Solar System materials. We also observe chondrules with positive ε50Ti and ε54Cr plot with a constant offset below the primitive chondrule mineral line (PCM), indicating that they are on the slope ∼1.0 in the oxygen three-isotope diagram. In contrast, chondrules with negative ε50Ti and ε54Cr increasingly deviate above from PCM line with increasing δ18O, suggesting that they are on a mixing trend with an ordinary chondrite-like isotope reservoir. Furthermore, the Δ17O-Mg# systematics of these chondrules indicate they formed in environments characterized by distinct abundances of dust and H2O ice. We posit that large-scale outward transport of nominally inner Solar System materials most likely occurred along the midplane associated with a viscously evolving disk and that CV and CK chondrules formed in local regions of enhanced gas pressure and dust density created by the formation of Jupiter.

Published
2020

14. Radial transport and nebular thermal processing of millimeter‐sized solids in the Solar protoplanetary disk inferred from Cr‐Ti‐O isotope systematics of chondrules.

Author

Fukuda, Kohei, Hibiya, Yuki, Kastelle, Craig R., Suzuki, Katsuhiko, Iizuka, Tsuyoshi, Yamashita, Katsuyuki, Helser, Thomas E., and Kita, Noriko T.

Abstract

Understanding the material transport and mixing processes in the Solar protoplanetary disk provides important constraints on the origin of chemical and isotopic diversities of our planets. The limited extent of radial transport and mixing between the inner and outer Solar System has been suggested based on a fundamental isotopic dichotomy between non‐carbonaceous (NC) and carbonaceous (CC) meteorite groups. The limited transport and mixing could be further tested by tracing the formation regions of individual meteoritic components, such as Ca‐Al‐rich inclusions (CAIs) and chondrules. Here, we show further evidence for the outward transport of CAIs and chondrules from the inner and subsequent thermal processing in the outer region of the protoplanetary disk based on the petrography and combined Cr‐Ti‐O isotope systematics of chondrules from the Vigarano‐like (CV) carbonaceous chondrite Allende. One chondrule studied consists of an olivine core that exhibits NC‐like Ti and O, but CC‐like Cr isotopic signatures, which is enclosed by a pyroxene igneous rim with CC‐like O isotope ratios. These observations indicate that the olivine core formed in the inner Solar System. The olivine core then migrated into the outer Solar System and experienced nebular thermal processing that generated the pyroxene igneous rim. The nebular thermal processing would result in Cr isotope exchange between the olivine core and CC‐like materials, but secondary alteration effects on the parent body are also responsible for the CC‐like Cr isotope signature. By combining previously reported Cr‐Ti‐O isotope systematics of CV chondrules, we show that some CV chondrules larger than ~1 mm would have formed in the inner Solar System. The accretion of the millimeter‐sized, inner Solar System solids onto the CV carbonaceous chondrite parent body would require their very early migration into the outer Solar System within the first 1 million years after the Solar System formation. [ABSTRACT FROM AUTHOR]

Published
2024
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15. Disequilibrium oxygen isotope distribution among aqueously altered minerals in Ryugu asteroid returned samples

Author

Kita, Noriko T., primary, Kitajima, Kouki, additional, Nagashima, Kazuhide, additional, Kawasaki, Noriyuki, additional, Sakamoto, Naoya, additional, Fujiya, Wataru, additional, Abe, Yoshinari, additional, Aléon, Jérôme, additional, Alexander, Conel M. O'D., additional, Amari, Sachiko, additional, Amelin, Yuri, additional, Bajo, Ken‐ichi, additional, Bizzarro, Martin, additional, Bouvier, Audrey, additional, Carlson, Richard W., additional, Chaussidon, Marc, additional, Choi, Byeon‐Gak, additional, Dauphas, Nicolas, additional, Davis, Andrew M., additional, Di Rocco, Tommaso, additional, Fukai, Ryota, additional, Gautam, Ikshu, additional, Haba, Makiko K., additional, Hibiya, Yuki, additional, Hidaka, Hiroshi, additional, Homma, Hisashi, additional, Hoppe, Peter, additional, Huss, Gary R., additional, Ichida, Kiyohiro, additional, Iizuka, Tsuyoshi, additional, Ireland, Trevor R., additional, Ishikawa, Akira, additional, Itoh, Shoichi, additional, Kleine, Thorsten, additional, Komatani, Shintaro, additional, Krot, Alexander N., additional, Liu, Ming‐Chang, additional, Masuda, Yuki, additional, McKeegan, Kevin D., additional, Morita, Mayu, additional, Motomura, Kazuko, additional, Moynier, Frédéric, additional, Nakai, Izumi, additional, Nguyen, Ann, additional, Nittler, Larry, additional, Onose, Morihiko, additional, Pack, Andreas, additional, Park, Changkun, additional, Piani, Laurette, additional, Qin, Liping, additional, Russell, Sara S., additional, Schönbächler, Maria, additional, Tafla, Lauren, additional, Tang, Haolan, additional, Terada, Kentaro, additional, Terada, Yasuko, additional, Usui, Tomohiro, additional, Wada, Sohei, additional, Wadhwa, Meenakshi, additional, Walker, Richard J., additional, Yamashita, Katsuyuki, additional, Yin, Qing‐Zhu, additional, Yokoyama, Tetsuya, additional, Yoneda, Shigekazu, additional, Young, Edward D., additional, Yui, Hiroharu, additional, Zhang, Ai‐Cheng, additional, Nakamura, Tomoki, additional, Naraoka, Hiroshi, additional, Noguchi, Takaaki, additional, Okazaki, Ryuji, additional, Sakamoto, Kanako, additional, Yabuta, Hikaru, additional, Abe, Masanao, additional, Miyazaki, Akiko, additional, Nakato, Aiko, additional, Nishimura, Masahiro, additional, Okada, Tatsuaki, additional, Yada, Toru, additional, Yogata, Kasumi, additional, Nakazawa, Satoru, additional, Saiki, Takanao, additional, Tanaka, Satoshi, additional, Terui, Fuyuto, additional, Tsuda, Yuichi, additional, Watanabe, Sei‐ichiro, additional, Yoshikawa, Makoto, additional, Tachibana, Shogo, additional, and Yurimoto, Hisayoshi, additional

Published
2024
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16. Author Correction: Contribution of Ryugu-like material to Earth’s volatile inventory by Cu and Zn isotopic analysis

Author

Paquet, Marine, Moynier, Frederic, Yokoyama, Tetsuya, Dai, Wei, Hu, Yan, Abe, Yoshinari, Aléon, Jérôme, O’D. Alexander, Conel M., Amari, Sachiko, Amelin, Yuri, Bajo, Ken-ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard W., Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew M., Di Rocco, Tommaso, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary R., Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Ito, Motoo, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko T., Kitajima, Kouki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander N., Liu, Ming-Chang, Masuda, Yuki, McKeegan, Kevin D., Morita, Mayu, Motomura, Kazuko, Nakai, Izumi, Nagashima, Kazuhide, Nesvorný, David, Nguyen, Ann N., Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Russell, Sara S., Sakamoto, Naoya, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard J., Yamashita, Katsuyuki, Yin, Qing-Zhu, Yoneda, Shigekazu, Young, Edward D., Yui, Hiroharu, Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-ichiro, Yoshikawa, Makoto, Tachibana, Shogo, and Yurimoto, Hisayoshi

Published
2023
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17. Analysis of Cation Composition in Dolomites on the Intact Particles Sampled from Asteroid Ryugu

Author

Morita, Mayu, Yui, Hiroharu, Urashima, Shu Hei, Onose, Morihiko, Komatani, Shintaro, Nakai, Izumi, Abe, Yoshinari, Terada, Yasuko, Homma, Hisashi, Motomura, Kazuko, Ichida, Kiyohiro, Yokoyama, Tetsuya, Nagashima, Kazuhide, Aléon, Jérôme, Conel, Conel M., Amari, Sachiko, Amelin, Yuri, Bajo, Ken-ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard W., Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew M., Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hibiya, Yuki, Hidaka, Hiroshi, Hoppe, Peter, Huss, Gary R., Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko T., Kitajima, Kouki, Kleine, Thorsten, Krot, Sasha, Liu, Ming-Chang, Masuda, Yuki, Moynier, Frédéric, Nguyen, Ann, Nittler, Larry, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Rocco, Tommaso Di, Russell, Sara S., Sakamoto, Naoya, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard J., Yamashita, Katsuyuki, Yin, Qing-Zhu, Yoneda, Shigekazu, Young, Edward D., Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-ichiro, Yoshikawa, Makoto, Tachibana, Shogo, Yurimoto, Hisayoshi, Morita, Mayu, Yui, Hiroharu, Urashima, Shu Hei, Onose, Morihiko, Komatani, Shintaro, Nakai, Izumi, Abe, Yoshinari, Terada, Yasuko, Homma, Hisashi, Motomura, Kazuko, Ichida, Kiyohiro, Yokoyama, Tetsuya, Nagashima, Kazuhide, Aléon, Jérôme, Conel, Conel M., Amari, Sachiko, Amelin, Yuri, Bajo, Ken-ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard W., Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew M., Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hibiya, Yuki, Hidaka, Hiroshi, Hoppe, Peter, Huss, Gary R., Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko T., Kitajima, Kouki, Kleine, Thorsten, Krot, Sasha, Liu, Ming-Chang, Masuda, Yuki, Moynier, Frédéric, Nguyen, Ann, Nittler, Larry, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Rocco, Tommaso Di, Russell, Sara S., Sakamoto, Naoya, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard J., Yamashita, Katsuyuki, Yin, Qing-Zhu, Yoneda, Shigekazu, Young, Edward D., Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-ichiro, Yoshikawa, Makoto, Tachibana, Shogo, and Yurimoto, Hisayoshi

Abstract

Characterization of the elemental distribution of samples with rough surfaces has been strongly desired for the analysis of various natural and artificial materials. Particularly for pristine and rare analytes with micrometer sizes embedded on specimen surfaces, non-invasive and matrix effect-free analysis is required without surface polishing treatment. To satisfy these requirements, we proposed a new method employing the sequential combination of two imaging modalities, i.e., microenergy-dispersive X-ray fluorescence (micro-XRF) and Raman micro-spectroscopy. The applicability of the developed method is tested by the quantitative analysis of cation composition in micrometer-sized carbonate grains on the surfaces of intact particles sampled directly from the asteroid Ryugu. The first step of micro-XRF imaging enabled a quick search for the sparsely scattered and micrometer-sized carbonates by the codistributions of Ca2+ and Mn2+ on the Mg2+- and Fe2+-rich phyllosilicate matrix. The following step of Raman micro-spectroscopy probed the carbonate grains and analyzed their cation composition (Ca2+, Mg2+, and Fe2+ + Mn2+) in a matrix effect-free manner via the systematic Raman shifts of the lattice modes. The carbonates were basically assigned to ferroan dolomite bearing a considerable amount of Fe2+ + Mn2+ at around 10 atom %. These results are in good accordance with the assignments reported by scanning electron microscopy-energy-dispersive X-ray spectroscopy, where the thin-sectioned and surface-polished Ryugu particles were applicable. The proposed method requires neither sectioning nor surface polishing; hence, it can be applied to the remote sensing apparatus on spacecrafts and planetary rovers. Furthermore, the non-invasive and matrix effect-free characterization will provide a reliable analytical tool for quantitative analysis of the elemental distrib

Published
2024

20. Neodymium‐142 deficits and samarium neutron stratigraphy of C‐type asteroid (162173) Ryugu

Author

Torrano, Zachary A., primary, Jordan, Michelle K., additional, Mock, Timothy D., additional, Carlson, Richard W., additional, Gautam, Ikshu, additional, Haba, Makiko K., additional, Yokoyama, Tetsuya, additional, Abe, Yoshinari, additional, Aléon, Jérôme, additional, Alexander, Conel, additional, Amari, Sachiko, additional, Amelin, Yuri, additional, Bajo, Ken‐ichi, additional, Bizzarro, Martin, additional, Bouvier, Audrey, additional, Chaussidon, Marc, additional, Choi, Byeon‐Gak, additional, Dauphas, Nicolas, additional, Davis, Andrew M., additional, Di Rocco, Tommaso, additional, Fujiya, Wataru, additional, Fukai, Ryota, additional, Hibiya, Yuki, additional, Hidaka, Hiroshi, additional, Homma, Hisashi, additional, Hoppe, Peter, additional, Huss, Gary R., additional, Ichida, Kiyohiro, additional, Iizuka, Tsuyoshi, additional, Ireland, Trevor, additional, Ishikawa, Akira, additional, Itoh, Shoichi, additional, Kawasaki, Noriyuki, additional, Kita, Noriko T., additional, Kitajima, Koki, additional, Kleine, Thorsten, additional, Komatani, Shintaro, additional, Krot, Alexander N., additional, Liu, Ming‐Chang, additional, Masuda, Yuki, additional, McKeegan, Kevin D., additional, Morita, Mayu, additional, Motomura, Kazuko, additional, Moynier, Frédéric, additional, Nakai, Izumi, additional, Nagashima, Kazuhide, additional, Nguyen, Ann, additional, Nittler, Larry, additional, Onose, Morihiko, additional, Pack, Andreas, additional, Park, Changkun, additional, Piani, Laurette, additional, Qin, Liping, additional, Russell, Sara, additional, Sakamoto, Naoya, additional, Schönbächler, Maria, additional, Tafla, Lauren, additional, Tang, Haolan, additional, Terada, Kentaro, additional, Terada, Yasuko, additional, Usui, Tomohiro, additional, Wada, Sohei, additional, Wadhwa, Meenakshi, additional, Walker, Richard J., additional, Yamashita, Katsuyuki, additional, Yin, Qing‐Zhu, additional, Yoneda, Shigekazu, additional, Young, Edward D., additional, Yui, Hiroharu, additional, Zhang, Ai‐Cheng, additional, Nakamura, Tomoki, additional, Naraoka, Hiroshi, additional, Noguchi, Takaaki, additional, Okazaki, Ryuji, additional, Sakamoto, Kanako, additional, Yabuta, Hikaru, additional, Abe, Masanao, additional, Miyazaki, Akiko, additional, Nakato, Aiko, additional, Nishimura, Masahiro, additional, Okada, Tatsuaki, additional, Yada, Toru, additional, Yogata, Kasumi, additional, Nakazawa, Satoru, additional, Saiki, Takanao, additional, Tanaka, Satoshi, additional, Terui, Fuyuto, additional, Tsuda, Yuichi, additional, Watanabe, Sei‐ichiro, additional, Yoshikawa, Makoto, additional, Tachibana, Shogo, additional, and Yurimoto, Hisayoshi, additional

Published
2023
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21. The Magnesium Isotope Composition of Samples Returned from Asteroid Ryugu

Author

Bizzarro, Martin, primary, Schiller, Martin, additional, Yokoyama, Tetsuya, additional, Abe, Yoshinari, additional, Aléon, Jérôme, additional, Alexander, Conel M. O’D., additional, Amari, Sachiko, additional, Amelin, Yuri, additional, Bajo, Ken-ichi, additional, Bouvier, Audrey, additional, Carlson, Richard W., additional, Chaussidon, Marc, additional, Choi, Byeon-Gak, additional, Dauphas, Nicolas, additional, Davis, Andrew M., additional, Di Rocco, Tommaso, additional, Fujiya, Wataru, additional, Fukai, Ryota, additional, Gautam, Ikshu, additional, Haba, Makiko K., additional, Hibiya, Yuki, additional, Hidaka, Hiroshi, additional, Homma, Hisashi, additional, Hoppe, Peter, additional, Huss, Gary R., additional, Ichida, Kiyohiro, additional, Iizuka, Tsuyoshi, additional, Ireland, Trevor R., additional, Ishikawa, Akira, additional, Itoh, Shoichi, additional, Kawasaki, Noriyuki, additional, Kita, Noriko T., additional, Kitajima, Kouki, additional, Kleine, Thorsten, additional, Komatani, Shintaro, additional, Krot, Alexander N., additional, Liu, Ming-Chang, additional, Masuda, Yuki, additional, Morita, Mayu, additional, Moynier, Fréderic, additional, Motomura, Kazuko, additional, Nakai, Izumi, additional, Nagashima, Kazuhide, additional, Nesvorný, David, additional, Nguyen, Ann, additional, Nittler, Larry, additional, Onose, Morihiko, additional, Pack, Andreas, additional, Park, Changkun, additional, Piani, Laurette, additional, Qin, Liping, additional, Russell, Sara S., additional, Sakamoto, Naoya, additional, Schönbächler, Maria, additional, Tafla, Lauren, additional, Tang, Haolan, additional, Terada, Kentaro, additional, Terada, Yasuko, additional, Usui, Tomohiro, additional, Wada, Sohei, additional, Wadhwa, Meenakshi, additional, Walker, Richard J., additional, Yamashita, Katsuyuki, additional, Yin, Qing-Zhu, additional, Yoneda, Shigekazu, additional, Young, Edward D., additional, Yui, Hiroharu, additional, Zhang, Ai-Cheng, additional, Nakamura, Tomoki, additional, Naraoka, Hiroshi, additional, Noguchi, Takaaki, additional, Okazaki, Ryuji, additional, Sakamoto, Kanako, additional, Yabuta, Hikaru, additional, Abe, Masanao, additional, Miyazaki, Akiko, additional, Nakato, Aiko, additional, Nishimura, Masahiro, additional, Okada, Tatsuaki, additional, Yada, Toru, additional, Yogata, Kasumi, additional, Nakazawa, Satoru, additional, Saiki, Takanao, additional, Tanaka, Satoshi, additional, Terui, Fuyuto, additional, Tsuda, Yuichi, additional, Watanabe, Sei-ichiro, additional, Yoshikawa, Makoto, additional, Tachibana, Shogo, additional, and Yurimoto, Hisayoshi, additional

Published
2023
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23. Considerations for'Development of the Handling of the Accounting for and Disclosure of Stock-Based Compensation' by the Accounting Standards Advisory Council of the Financial Accounting Standards Foundation

Author

YAMASHITA, Katsuyuki

Subjects
Stock-based Compensation, Share Award Rights, Accounting Standards, Contribution in Kind
Abstract

The Accounting Standards Advisory Council of the Financial Accounting Standards Foundation (FASF) is currently deliberating on the theme of the “Development of the handling of the accounting for and disclosure of stock-based compensation”. This article discusses the “development of accounting standards for so-called stock-based compensation transactions involving contribution in kind,” which is the first area of deliberations by the Council on this theme, by focusing on the three issues of “the timing of the increase in share capital for before-the-fact delivery transactions”, “the amount of share capital for after-the-fact delivery transactions” and “share award rights for after-the-fact delivery transactions”., 「制度会計における課題」特集

Published
2023

24. The Oxygen Isotopic Composition of Samples Returned from Asteroid Ryugu with Implications for the Nature of the Parent Planetesimal

Author

Tang, Haolan, primary, Young, Edward D., additional, Tafla, Lauren, additional, Pack, Andreas, additional, Di Rocco, Tommaso, additional, Abe, Yoshinari, additional, Aléon, Jérôme, additional, M. O’D. Alexander, Conel, additional, Amari, Sachiko, additional, Amelin, Yuri, additional, Bajo, Ken-ichi, additional, Bizzarro, Martin, additional, Bouvier, Audrey, additional, Carlson, Richard W., additional, Chaussidon, Marc, additional, Choi, Byeon-Gak, additional, Dauphas, Nicolas, additional, Davis, Andrew M., additional, Fujiya, Wataru, additional, Fukai, Ryota, additional, Gautam, Ikshu, additional, Haba, Makiko K., additional, Hibiya, Yuki, additional, Hidaka, Hiroshi, additional, Homma, Hisashi, additional, Hoppe, Peter, additional, Huss, Gary R., additional, Ichida, Kiyohiro, additional, Iizuka, Tsuyoshi, additional, Ireland, Trevor R., additional, Ishikawa, Akira, additional, Ito, Motoo, additional, Itoh, Shoichi, additional, Kawasaki, Noriyuki, additional, Kita, Noriko T., additional, Kitajima, Kouki, additional, Kleine, Thorsten, additional, Komatani, Shintaro, additional, Krot, Alexander N., additional, Liu, Ming-Chang, additional, Masuda, Yuki, additional, McKeegan, Kevin D., additional, Morita, Mayu, additional, Motomura, Kazuko, additional, Moynier, Frédéric, additional, Nagashima, Kazuhide, additional, Nakai, Izumi, additional, Nguyen, Ann, additional, Nittler, Larry, additional, Onose, Morihiko, additional, Park, Changkun, additional, Piani, Laurette, additional, Qin, Liping, additional, Russell, Sara S., additional, Sakamoto, Naoya, additional, Schönbächler, Maria, additional, Terada, Kentaro, additional, Terada, Yasuko, additional, Usui, Tomohiro, additional, Wada, Sohei, additional, Wadhwa, Meenakshi, additional, Walker, Richard J., additional, Yamashita, Katsuyuki, additional, Yin, Qing-Zhu, additional, Yokoyama, Tetsuya, additional, Yoneda, Shigekazu, additional, Yui, Hiroharu, additional, Zhang, Ai-Cheng, additional, Nakamura, Tomoki, additional, Naraoka, Hiroshi, additional, Noguchi, Takaaki, additional, Okazaki, Ryuji, additional, Sakamoto, Kanako, additional, Yabuta, Hikaru, additional, Abe, Masanao, additional, Miyazaki, Akiko, additional, Nakato, Aiko, additional, Nishimura, Masahiro, additional, Okada, Tatsuaki, additional, Yada, Toru, additional, Yogata, Kasumi, additional, Nakazawa, Satoru, additional, Saiki, Takanao, additional, Tanaka, Satoshi, additional, Terui, Fuyuto, additional, Tsuda, Yuichi, additional, Watanabe, Sei-ichiro, additional, Yoshikawa, Makoto, additional, Tachibana, Shogo, additional, and Yurimoto, Hisayoshi, additional

Published
2023
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25. Hydrogen Isotopic Composition of Hydrous Minerals in Asteroid Ryugu

Author

Piani, Laurette, primary, Nagashima, Kazuhide, additional, Kawasaki, Noriyuki, additional, Sakamoto, Naoya, additional, Bajo, Ken-ichi, additional, Abe, Yoshinari, additional, Aléon, Jérôme, additional, O’D. Alexander, Conel M., additional, Amari, Sachiko, additional, Amelin, Yuri, additional, Bizzarro, Martin, additional, Bouvier, Audrey, additional, Carlson, Richard W., additional, Chaussidon, Marc, additional, Choi, Byeon-Gak, additional, Dauphas, Nicolas, additional, Davis, Andrew M., additional, Di Rocco, Tommaso, additional, Fujiya, Wataru, additional, Fukai, Ryota, additional, Gautam, Ikshu, additional, Haba, Makiko K., additional, Hibiya, Yuki, additional, Hidaka, Hiroshi, additional, Homma, Hisashi, additional, Hoppe, Peter, additional, Huss, Gary R., additional, Ichida, Kiyohiro, additional, Iizuka, Tsuyoshi, additional, Ireland, Trevor R., additional, Ishikawa, Akira, additional, Itoh, Shoichi, additional, Kita, Noriko T., additional, Kitajima, Kouki, additional, Kleine, Thorsten, additional, Komatani, Shintaro, additional, Krot, Alexander N., additional, Liu, Ming-Chang, additional, Masuda, Yuki, additional, McKeegan, Kevin D., additional, Morita, Mayu, additional, Motomura, Kazuko, additional, Moynier, Frédéric, additional, Nakai, Izumi, additional, Nguyen, Ann, additional, Nittler, Larry, additional, Onose, Morihiko, additional, Pack, Andreas, additional, Park, Changkun, additional, Qin, Liping, additional, Russell, Sara S., additional, Schönbächler, Maria, additional, Tafla, Lauren, additional, Tang, Haolan, additional, Terada, Kentaro, additional, Terada, Yasuko, additional, Usui, Tomohiro, additional, Wada, Sohei, additional, Wadhwa, Meenakshi, additional, Walker, Richard J., additional, Yamashita, Katsuyuki, additional, Yin, Qing-Zhu, additional, Yokoyama, Tetsuya, additional, Yoneda, Shigekazu, additional, Young, Edward D., additional, Yui, Hiroharu, additional, Zhang, Ai-Cheng, additional, Nakamura, Tomoki, additional, Naraoka, Hiroshi, additional, Okazaki, Ryuji, additional, Sakamoto, Kanako, additional, Yabuta, Hikaru, additional, Abe, Masanao, additional, Miyazaki, Akiko, additional, Nakato, Aiko, additional, Nishimura, Masahiro, additional, Okada, Tatsuaki, additional, Yada, Toru, additional, Yogata, Kasumi, additional, Nakazawa, Satoru, additional, Saiki, Takanao, additional, Tanaka, Satoshi, additional, Terui, Fuyuto, additional, Tsuda, Yuichi, additional, Watanabe, Sei-ichiro, additional, Yoshikawa, Makoto, additional, Tachibana, Shogo, additional, and Yurimoto, Hisayoshi, additional

Published
2023
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26. Carbonate record of temporal change in oxygen fugacity and gaseous species in asteroid Ryugu

Author

Fujiya, Wataru, Kawasaki, Noriyuki, Nagashima, Kazuhide, Sakamoto, Naoya, O'D. Alexander, Conel M., Kita, Noriko T., Kitajima, Kouki, Abe, Yoshinari, Aleon, Jerome, Amari, Sachiko, Amelin, Yuri, Bajo, Ken-ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard W., Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew M., Di Rocco, Tommaso, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary R., Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Itoh, Shoichi, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander N., Liu, Ming-Chang, Masuda, Yuki, McKeegan, Kevin D., Morita, Mayu, Motomura, Kazuko, Moynier, Frederic, Nakai, Izumi, Nguyen, Ann, Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Russell, Sara S., Schonbachler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard J., Yamashita, Katsuyuki, Yin, Qing-Zhu, Yokoyama, Tetsuya, Yoneda, Shigekazu, Young, Edward D., Yui, Hiroharu, Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-ichiro, Yoshikawa, Makoto, Tachibana, Shogo, Yurimoto, Hisayoshi, Fujiya, Wataru, Kawasaki, Noriyuki, Nagashima, Kazuhide, Sakamoto, Naoya, O'D. Alexander, Conel M., Kita, Noriko T., Kitajima, Kouki, Abe, Yoshinari, Aleon, Jerome, Amari, Sachiko, Amelin, Yuri, Bajo, Ken-ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard W., Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew M., Di Rocco, Tommaso, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary R., Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Itoh, Shoichi, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander N., Liu, Ming-Chang, Masuda, Yuki, McKeegan, Kevin D., Morita, Mayu, Motomura, Kazuko, Moynier, Frederic, Nakai, Izumi, Nguyen, Ann, Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Russell, Sara S., Schonbachler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard J., Yamashita, Katsuyuki, Yin, Qing-Zhu, Yokoyama, Tetsuya, Yoneda, Shigekazu, Young, Edward D., Yui, Hiroharu, Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-ichiro, Yoshikawa, Makoto, Tachibana, Shogo, and Yurimoto, Hisayoshi

Abstract

The Hayabusa2 spacecraft explored asteroid Ryugu and brought its surface materials to Earth. Ryugu samples resemble Ivuna-type (CI) chondrites-the most chemically primitive meteorites-and contain secondary phyllosilicates and carbonates, which are indicative of aqueous alteration. Understanding the conditions (such as temperature, redox state and fluid composition) during aqueous alteration is crucial to elucidating how Ryugu evolved to its present state, but little is known about the temporal changes in these conditions. Here we show that calcium carbonate (calcite) grains in Ryugu and Ivuna samples have variable O-18/O-16 and C-13/C-12 ratios that are, respectively, 24-46 & PTSTHOUSND; and 65-108 & PTSTHOUSND; greater than terrestrial standard values, whereas those of calcium-magnesium carbonate (dolomite) grains are much more homogeneous, ranging within 31-36 & PTSTHOUSND; for oxygen and 67-75 & PTSTHOUSND; for carbon. We infer that the calcite precipitated first over a wide range of temperatures and oxygen partial pressures, and that the proportion of gaseous CO2/CO/CH4 molecules changed temporally. By contrast, the dolomite formed later in a more oxygen-rich and thus CO2-dominated environment when the system was approaching equilibrium. The characteristic isotopic compositions of secondary carbonates in Ryugu and Ivuna are not observed for other hydrous meteorites, suggesting a unique evolutionary pathway for their parent asteroid(s). The asteroid Ryugu experienced aqueous alteration under changing temperature and redox conditions, according to an isotopic analysis of secondary calcite and dolomite grains in samples from Ryugu obtained by the Hayabusa2 spacecraft.

Published
2023

27. The Oxygen Isotopic Composition of Samples Returned from Asteroid Ryugu with Implications for the Nature of the Parent Planetesimal

Author

Tang, Haolan, Young, Edward D., Tafla, Lauren, Pack, Andreas, Di Rocco, Tommaso, Abe, Yoshinari, Aléon, Jérôme, Alexander, Conel M. O'D., Amari, Sachiko, Amelin, Yuri, Bajo, Ken-ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard W., Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew M., Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary R., Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Ito, Motoo, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko T., Kitajima, Kouki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander N., Liu, Ming-Chang, Masuda, Yuki, McKeegan, Kevin D., Morita, Mayu, Motomura, Kazuko, Moynier, Frédéric, Nagashima, Kazuhide, Nakai, Izumi, Nguyen, Ann, Nittler, Larry, Onose, Morihiko, Park, Changkun, Piani, Laurette, Qin, Liping, Russell, Sara S., Sakamoto, Naoya, Schönbächler, Maria, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard J., Yamashita, Katsuyuki, Yin, Qing-Zhu, Yokoyama, Tetsuya, Yoneda, Shigekazu, Yui, Hiroharu, Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-ichiro, Yoshikawa, Makoto, Tachibana, Shogo, Yurimoto, Hisayoshi, Tang, Haolan, Young, Edward D., Tafla, Lauren, Pack, Andreas, Di Rocco, Tommaso, Abe, Yoshinari, Aléon, Jérôme, Alexander, Conel M. O'D., Amari, Sachiko, Amelin, Yuri, Bajo, Ken-ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard W., Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew M., Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary R., Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Ito, Motoo, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko T., Kitajima, Kouki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander N., Liu, Ming-Chang, Masuda, Yuki, McKeegan, Kevin D., Morita, Mayu, Motomura, Kazuko, Moynier, Frédéric, Nagashima, Kazuhide, Nakai, Izumi, Nguyen, Ann, Nittler, Larry, Onose, Morihiko, Park, Changkun, Piani, Laurette, Qin, Liping, Russell, Sara S., Sakamoto, Naoya, Schönbächler, Maria, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard J., Yamashita, Katsuyuki, Yin, Qing-Zhu, Yokoyama, Tetsuya, Yoneda, Shigekazu, Yui, Hiroharu, Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-ichiro, Yoshikawa, Makoto, Tachibana, Shogo, and Yurimoto, Hisayoshi

Abstract

We present oxygen isotopic analyses of fragments of the near-Earth Cb-type asteroid Ryugu returned by the Hayabusa2 spacecraft that reinforce the close correspondence between Ryugu and CI chondrites. Small differences between Ryugu samples and CI chondrites in can be explained at least in part by contamination of the latter by terrestrial water. The discovery that a randomly sampled C-complex asteroid is composed of CI-chondrite-like rock, combined with thermal models for formation prior to significant decay of the short-lived radioisotope 26Al, suggests that if lithified at the time of alteration, the parent body was small (≪50 km radius). If the parent planetesimal was large (>50 km in radius), it was likely composed of high-permeability, poorly lithified sediment rather than consolidated rock., We present oxygen isotopic analyses of fragments of the near-Earth Cb-type asteroid Ryugu returned by the Hayabusa2 spacecraft that reinforce the close correspondence between Ryugu and CI chondrites. Small differences between Ryugu samples and CI chondrites in can be explained at least in part by contamination of the latter by terrestrial water. The discovery that a randomly sampled C-complex asteroid is composed of CI-chondrite-like rock, combined with thermal models for formation prior to significant decay of the short-lived radioisotope 26Al, suggests that if lithified at the time of alteration, the parent body was small (≪50 km radius). If the parent planetesimal was large (>50 km in radius), it was likely composed of high-permeability, poorly lithified sediment rather than consolidated rock.

Published
2023

28. Abundant presolar grains and primordial organics preserved in carbon-rich exogenous clasts in asteroid Ryugu

Author

Nguyen, Ann N., Mane, Prajkta, Keller, Lindsay P., Piani, Laurette, Abe, Yoshinari, Aléon, Jérôme, Alexander, Conel M. O'D., Amari, Sachiko, Amelin, Yuri, Bajo, Ken-ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard W., Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew M., Di Rocco, Tommaso, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary R., Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko T., Kitajima, Kouki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander N., Liu, Ming-Chang, Masuda, Yuki, McKeegan, Kevin D., Morita, Mayu, Motomura, Kazuko, Moynier, Frédéric, Nakai, Izumi, Nagashima, Kazuhide, Nesvorný, David, Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Qin, Liping, Russell, Sara S., Sakamoto, Naoya, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard J., Yamashita, Katsuyuki, Yin, Qing-Zhu, Yokoyama, Tetsuya, Yoneda, Shigekazu, Young, Edward D., Yui, Hiroharu, Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-ichiro, Yoshikawa, Makoto, Tachibana, Shogo, Yurimoto, Hisayoshi, Nguyen, Ann N., Mane, Prajkta, Keller, Lindsay P., Piani, Laurette, Abe, Yoshinari, Aléon, Jérôme, Alexander, Conel M. O'D., Amari, Sachiko, Amelin, Yuri, Bajo, Ken-ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard W., Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew M., Di Rocco, Tommaso, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary R., Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko T., Kitajima, Kouki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander N., Liu, Ming-Chang, Masuda, Yuki, McKeegan, Kevin D., Morita, Mayu, Motomura, Kazuko, Moynier, Frédéric, Nakai, Izumi, Nagashima, Kazuhide, Nesvorný, David, Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Qin, Liping, Russell, Sara S., Sakamoto, Naoya, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard J., Yamashita, Katsuyuki, Yin, Qing-Zhu, Yokoyama, Tetsuya, Yoneda, Shigekazu, Young, Edward D., Yui, Hiroharu, Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-ichiro, Yoshikawa, Makoto, Tachibana, Shogo, and Yurimoto, Hisayoshi

Abstract

Preliminary analyses of asteroid Ryugu samples show kinship to aqueously altered CI (Ivuna-type) chondrites, suggesting similar origins. We report identification of C-rich, particularly primitive clasts in Ryugu samples that contain preserved presolar silicate grains and exceptional abundances of presolar SiC and isotopically anomalous organic matter. The high presolar silicate abundance (104 ppm) indicates that the clast escaped extensive alteration. The 5 to 10 times higher abundances of presolar SiC (~235 ppm), N-rich organic matter, organics with N isotopic anomalies (1.2%), and organics with C isotopic anomalies (0.2%) in the primitive clasts compared to bulk Ryugu suggest that the clasts formed in a unique part of the protoplanetary disk enriched in presolar materials. These clasts likely represent previously unsampled outer solar system material that accreted onto Ryugu after aqueous alteration ceased, consistent with Ryugu's rubble pile origin.

Published
2023

29. Samples returned from the asteroid Ryugu are similar to Ivuna-type carbonaceous meteorites

Author

Yokoyama, Tetsuya, Nagashima, Kazuhide, Nakai, Izumi, Young, Edward D., Abe, Yoshinari, Aleon, Jerome, Alexander, Conel M. O'D., Amari, Sachiko, Amelin, Yuri, Bajo, Ken-ichi, Bizzarro, Martin, Namiki, Noriyuki, Noda, Hirotomo, Noguchi, Rina, Ogawa, Naoko, Ogawa, Kazunori, Okada, Tatsuaki, Okamoto, Chisato, Ono, Go, Ozaki, Masanobu, Saiki, Takanao, Bouvier, Audrey, Sakatani, Naoya, Sawada, Hirotaka, Senshu, Hiroki, Shimaki, Yuri, Shirai, Kei, Sugita, Seiji, Takei, Yuto, Takeuchi, Hiroshi, Tanaka, Satoshi, Tatsumi, Eri, Carlson, Richard W., Terui, Fuyuto, Tsuda, Yuichi, Tsukizaki, Ryudo, Wada, Koji, Watanabe, Sei-ichiro, Yamada, Manabu, Yamada, Tetsuya, Yamamoto, Yukio, Yano, Hajime, Yokota, Yasuhiro, Chaussidon, Marc, Yoshihara, Keisuke, Yoshikawa, Makoto, Yoshikawa, Kent, Furuya, Shizuho, Hatakeda, Kentaro, Hayashi, Tasuku, Hitomi, Yuya, Kumagai, Kazuya, Miyazaki, Akiko, Nakato, Aiko, Choi, Byeon-Gak, Nishimura, Masahiro, Soejima, Hiromichi, Suzuki, Ayako, Yada, Toru, Yamamoto, Daiki, Yogata, Kasumi, Yoshitake, Miwa, Tachibana, Shogo, Yurimoto, Hisayoshi, Dauphas, Nicolas, Davis, Andrew M., Di Rocco, Tommaso, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary R., Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Ito, Motoo, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko T., Kitajima, Kouki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander N., Liu, Ming-Chang, Masuda, Yuki, McKeegan, Kevin D., Morita, Mayu, Motomura, Kazuko, Moynier, Frederic, Nguyen, Ann, Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Russell, Sara S., Sakamoto, Naoya, Schoenbaechler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard J., Yamashita, Katsuyuki, Yin, Qing-Zhu, Yoneda, Shigekazu, Yui, Hiroharu, Zhang, Ai-Cheng, Connolly Jr, Harold C., Lauretta, Dante S., Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Arakawa, Masahiko, Fujii, Atsushi, Hayakawa, Masahiko, Hirata, Naoyuki, Hirata, Naru, Honda, Rie, Honda, Chikatoshi, Hosoda, Satoshi, Iijima, Yu-ichi, Ikeda, Hitoshi, Ishiguro, Masateru, Ishihara, Yoshiaki, Iwata, Takahiro, Kawahara, Kosuke, Kikuchi, Shota, Kitazato, Kohei, Matsumoto, Koji, Matsuoka, Moe, Michikami, Tatsuhiro, Mimasu, Yuya, Miura, Akira, Morota, Tomokatsu, Nakazawa, Satoru, Yokoyama, Tetsuya, Nagashima, Kazuhide, Nakai, Izumi, Young, Edward D., Abe, Yoshinari, Aleon, Jerome, Alexander, Conel M. O'D., Amari, Sachiko, Amelin, Yuri, Bajo, Ken-ichi, Bizzarro, Martin, Namiki, Noriyuki, Noda, Hirotomo, Noguchi, Rina, Ogawa, Naoko, Ogawa, Kazunori, Okada, Tatsuaki, Okamoto, Chisato, Ono, Go, Ozaki, Masanobu, Saiki, Takanao, Bouvier, Audrey, Sakatani, Naoya, Sawada, Hirotaka, Senshu, Hiroki, Shimaki, Yuri, Shirai, Kei, Sugita, Seiji, Takei, Yuto, Takeuchi, Hiroshi, Tanaka, Satoshi, Tatsumi, Eri, Carlson, Richard W., Terui, Fuyuto, Tsuda, Yuichi, Tsukizaki, Ryudo, Wada, Koji, Watanabe, Sei-ichiro, Yamada, Manabu, Yamada, Tetsuya, Yamamoto, Yukio, Yano, Hajime, Yokota, Yasuhiro, Chaussidon, Marc, Yoshihara, Keisuke, Yoshikawa, Makoto, Yoshikawa, Kent, Furuya, Shizuho, Hatakeda, Kentaro, Hayashi, Tasuku, Hitomi, Yuya, Kumagai, Kazuya, Miyazaki, Akiko, Nakato, Aiko, Choi, Byeon-Gak, Nishimura, Masahiro, Soejima, Hiromichi, Suzuki, Ayako, Yada, Toru, Yamamoto, Daiki, Yogata, Kasumi, Yoshitake, Miwa, Tachibana, Shogo, Yurimoto, Hisayoshi, Dauphas, Nicolas, Davis, Andrew M., Di Rocco, Tommaso, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary R., Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Ito, Motoo, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko T., Kitajima, Kouki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander N., Liu, Ming-Chang, Masuda, Yuki, McKeegan, Kevin D., Morita, Mayu, Motomura, Kazuko, Moynier, Frederic, Nguyen, Ann, Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Russell, Sara S., Sakamoto, Naoya, Schoenbaechler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard J., Yamashita, Katsuyuki, Yin, Qing-Zhu, Yoneda, Shigekazu, Yui, Hiroharu, Zhang, Ai-Cheng, Connolly Jr, Harold C., Lauretta, Dante S., Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Arakawa, Masahiko, Fujii, Atsushi, Hayakawa, Masahiko, Hirata, Naoyuki, Hirata, Naru, Honda, Rie, Honda, Chikatoshi, Hosoda, Satoshi, Iijima, Yu-ichi, Ikeda, Hitoshi, Ishiguro, Masateru, Ishihara, Yoshiaki, Iwata, Takahiro, Kawahara, Kosuke, Kikuchi, Shota, Kitazato, Kohei, Matsumoto, Koji, Matsuoka, Moe, Michikami, Tatsuhiro, Mimasu, Yuya, Miura, Akira, Morota, Tomokatsu, and Nakazawa, Satoru

Abstract

Carbonaceous meteorites are thought to be fragments of C-type (carbonaceous) asteroids. Samples of the C-type asteroid (162173) Ryugu were retrieved by the Hayabusa2 spacecraft. We measured the mineralogy and bulk chemical and isotopic compositions of Ryugu samples. The samples are mainly composed of materials similar to those of carbonaceous chondrite meteorites, particularly the CI (Ivuna-type) group. The samples consist predominantly of minerals formed in aqueous fluid on a parent planetesimal. The primary minerals were altered by fluids at a temperature of 37 degrees +/- 10 degrees C, about 5.2(-0.7)(+0.8) million (statistical) or 5.2(-2.1)(+1.6) million (systematic) years after the formation of the first solids in the Solar System. After aqueous alteration, the Ryugu samples were likely never heated above similar to 100 degrees C. The samples have a chemical composition that more closely resembles that of the Sun's photosphere than other natural samples do.

Published
2023

30. Contribution of Ryugu-like material to Earth’s volatile inventory by Cu and Zn isotopic analysis:[Inkl. Correction]

Author

Paquet, Marine, Moynier, Frederic, Yokoyama, Tetsuya, Dai, Wei, Hu, Yan, Abe, Yoshinari, Aléon, Jérôme, Alexander, Conel M. O'D., Amari, Sachiko, Amelin, Yuri, Bajo, Ken-ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard W., Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew M., Di Rocco, Tommaso, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary R., Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Ito, Motoo, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko T., Kitajima, Kouki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander N., Liu, Ming-Chang, Masuda, Yuki, McKeegan, Kevin D., Morita, Mayu, Motomura, Kazuko, Nakai, Izumi, Nagashima, Kazuhide, Nesvorný, David, Nguyen, Ann N., Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Russell, Sara S., Sakamoto, Naoya, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard J., Yamashita, Katsuyuki, Yin, Qing-Zhu, Yoneda, Shigekazu, Young, Edward D., Yui, Hiroharu, Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-ichiro, Yoshikawa, Makoto, Tachibana, Shogo, Yurimoto, Hisayoshi, Paquet, Marine, Moynier, Frederic, Yokoyama, Tetsuya, Dai, Wei, Hu, Yan, Abe, Yoshinari, Aléon, Jérôme, Alexander, Conel M. O'D., Amari, Sachiko, Amelin, Yuri, Bajo, Ken-ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard W., Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew M., Di Rocco, Tommaso, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary R., Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Ito, Motoo, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko T., Kitajima, Kouki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander N., Liu, Ming-Chang, Masuda, Yuki, McKeegan, Kevin D., Morita, Mayu, Motomura, Kazuko, Nakai, Izumi, Nagashima, Kazuhide, Nesvorný, David, Nguyen, Ann N., Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Russell, Sara S., Sakamoto, Naoya, Schönbächler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard J., Yamashita, Katsuyuki, Yin, Qing-Zhu, Yoneda, Shigekazu, Young, Edward D., Yui, Hiroharu, Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-ichiro, Yoshikawa, Makoto, Tachibana, Shogo, and Yurimoto, Hisayoshi

Abstract

Initial analyses showed that asteroid Ryugu’s composition is close to CI (Ivuna-like) carbonaceous chondrites (CCs) – the chemically most primitive meteorites, characterized by near-solar abundances for most elements. However, some isotopic signatures (for example, Ti, Cr) overlap with other CC groups, so the details of the link between Ryugu and the CI chondrites are not yet fully clear. Here we show that Ryugu and CI chondrites have the same zinc and copper isotopic composition. As the various chondrite groups have very distinct Zn and Cu isotopic signatures, our results point at a common genetic heritage between Ryugu and CI chondrites, ruling out any affinity with other CC groups. Since Ryugu’s pristine samples match the solar elemental composition for many elements, their Zn and Cu isotopic compositions likely represent the best estimates of the solar composition. Earth’s mass-independent Zn isotopic composition is intermediate between Ryugu/CC and non-carbonaceous chondrites (NCs), suggesting a contribution of Ryugu-like material to Earth’s budgets of Zn and other moderately volatile elements.

Published
2023

32. Samples returned from the asteroid Ryugu are similar to Ivuna-type carbonaceous meteorites

Author

Yokoyama, Tetsuya, primary, Nagashima, Kazuhide, additional, Nakai, Izumi, additional, Young, Edward D., additional, Abe, Yoshinari, additional, Aléon, Jérôme, additional, Alexander, Conel M. O’D., additional, Amari, Sachiko, additional, Amelin, Yuri, additional, Bajo, Ken-ichi, additional, Bizzarro, Martin, additional, Bouvier, Audrey, additional, Carlson, Richard W., additional, Chaussidon, Marc, additional, Choi, Byeon-Gak, additional, Dauphas, Nicolas, additional, Davis, Andrew M., additional, Di Rocco, Tommaso, additional, Fujiya, Wataru, additional, Fukai, Ryota, additional, Gautam, Ikshu, additional, Haba, Makiko K., additional, Hibiya, Yuki, additional, Hidaka, Hiroshi, additional, Homma, Hisashi, additional, Hoppe, Peter, additional, Huss, Gary R., additional, Ichida, Kiyohiro, additional, Iizuka, Tsuyoshi, additional, Ireland, Trevor R., additional, Ishikawa, Akira, additional, Ito, Motoo, additional, Itoh, Shoichi, additional, Kawasaki, Noriyuki, additional, Kita, Noriko T., additional, Kitajima, Kouki, additional, Kleine, Thorsten, additional, Komatani, Shintaro, additional, Krot, Alexander N., additional, Liu, Ming-Chang, additional, Masuda, Yuki, additional, McKeegan, Kevin D., additional, Morita, Mayu, additional, Motomura, Kazuko, additional, Moynier, Frédéric, additional, Nguyen, Ann, additional, Nittler, Larry, additional, Onose, Morihiko, additional, Pack, Andreas, additional, Park, Changkun, additional, Piani, Laurette, additional, Qin, Liping, additional, Russell, Sara S., additional, Sakamoto, Naoya, additional, Schönbächler, Maria, additional, Tafla, Lauren, additional, Tang, Haolan, additional, Terada, Kentaro, additional, Terada, Yasuko, additional, Usui, Tomohiro, additional, Wada, Sohei, additional, Wadhwa, Meenakshi, additional, Walker, Richard J., additional, Yamashita, Katsuyuki, additional, Yin, Qing-Zhu, additional, Yoneda, Shigekazu, additional, Yui, Hiroharu, additional, Zhang, Ai-Cheng, additional, Connolly, Harold C., additional, Lauretta, Dante S., additional, Nakamura, Tomoki, additional, Naraoka, Hiroshi, additional, Noguchi, Takaaki, additional, Okazaki, Ryuji, additional, Sakamoto, Kanako, additional, Yabuta, Hikaru, additional, Abe, Masanao, additional, Arakawa, Masahiko, additional, Fujii, Atsushi, additional, Hayakawa, Masahiko, additional, Hirata, Naoyuki, additional, Hirata, Naru, additional, Honda, Rie, additional, Honda, Chikatoshi, additional, Hosoda, Satoshi, additional, Iijima, Yu-ichi, additional, Ikeda, Hitoshi, additional, Ishiguro, Masateru, additional, Ishihara, Yoshiaki, additional, Iwata, Takahiro, additional, Kawahara, Kosuke, additional, Kikuchi, Shota, additional, Kitazato, Kohei, additional, Matsumoto, Koji, additional, Matsuoka, Moe, additional, Michikami, Tatsuhiro, additional, Mimasu, Yuya, additional, Miura, Akira, additional, Morota, Tomokatsu, additional, Nakazawa, Satoru, additional, Namiki, Noriyuki, additional, Noda, Hirotomo, additional, Noguchi, Rina, additional, Ogawa, Naoko, additional, Ogawa, Kazunori, additional, Okada, Tatsuaki, additional, Okamoto, Chisato, additional, Ono, Go, additional, Ozaki, Masanobu, additional, Saiki, Takanao, additional, Sakatani, Naoya, additional, Sawada, Hirotaka, additional, Senshu, Hiroki, additional, Shimaki, Yuri, additional, Shirai, Kei, additional, Sugita, Seiji, additional, Takei, Yuto, additional, Takeuchi, Hiroshi, additional, Tanaka, Satoshi, additional, Tatsumi, Eri, additional, Terui, Fuyuto, additional, Tsuda, Yuichi, additional, Tsukizaki, Ryudo, additional, Wada, Koji, additional, Watanabe, Sei-ichiro, additional, Yamada, Manabu, additional, Yamada, Tetsuya, additional, Yamamoto, Yukio, additional, Yano, Hajime, additional, Yokota, Yasuhiro, additional, Yoshihara, Keisuke, additional, Yoshikawa, Makoto, additional, Yoshikawa, Kent, additional, Furuya, Shizuho, additional, Hatakeda, Kentaro, additional, Hayashi, Tasuku, additional, Hitomi, Yuya, additional, Kumagai, Kazuya, additional, Miyazaki, Akiko, additional, Nakato, Aiko, additional, Nishimura, Masahiro, additional, Soejima, Hiromichi, additional, Suzuki, Ayako, additional, Yada, Toru, additional, Yamamoto, Daiki, additional, Yogata, Kasumi, additional, Yoshitake, Miwa, additional, Tachibana, Shogo, additional, and Yurimoto, Hisayoshi, additional

Published
2023
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34. Contribution of Ryugu-like material to Earth’s volatile inventory by Cu and Zn isotopic analysis

Author

Paquet, Marine, primary, Moynier, Frederic, additional, Yokoyama, Tetsuya, additional, Dai, Wei, additional, Hu, Yan, additional, Abe, Yoshinari, additional, Aléon, Jérôme, additional, O’D. Alexander, Conel M., additional, Amari, Sachiko, additional, Amelin, Yuri, additional, Bajo, Ken-ichi, additional, Bizzarro, Martin, additional, Bouvier, Audrey, additional, Carlson, Richard W., additional, Chaussidon, Marc, additional, Choi, Byeon-Gak, additional, Dauphas, Nicolas, additional, Davis, Andrew M., additional, Di Rocco, Tommaso, additional, Fujiya, Wataru, additional, Fukai, Ryota, additional, Gautam, Ikshu, additional, Haba, Makiko K., additional, Hibiya, Yuki, additional, Hidaka, Hiroshi, additional, Homma, Hisashi, additional, Hoppe, Peter, additional, Huss, Gary R., additional, Ichida, Kiyohiro, additional, Iizuka, Tsuyoshi, additional, Ireland, Trevor R., additional, Ishikawa, Akira, additional, Ito, Motoo, additional, Itoh, Shoichi, additional, Kawasaki, Noriyuki, additional, Kita, Noriko T., additional, Kitajima, Kouki, additional, Kleine, Thorsten, additional, Komatani, Shintaro, additional, Krot, Alexander N., additional, Liu, Ming-Chang, additional, Masuda, Yuki, additional, McKeegan, Kevin D., additional, Morita, Mayu, additional, Motomura, Kazuko, additional, Nakai, Izumi, additional, Nagashima, Kazuhide, additional, Nesvorný, David, additional, Nguyen, Ann N., additional, Nittler, Larry, additional, Onose, Morihiko, additional, Pack, Andreas, additional, Park, Changkun, additional, Piani, Laurette, additional, Qin, Liping, additional, Russell, Sara S., additional, Sakamoto, Naoya, additional, Schönbächler, Maria, additional, Tafla, Lauren, additional, Tang, Haolan, additional, Terada, Kentaro, additional, Terada, Yasuko, additional, Usui, Tomohiro, additional, Wada, Sohei, additional, Wadhwa, Meenakshi, additional, Walker, Richard J., additional, Yamashita, Katsuyuki, additional, Yin, Qing-Zhu, additional, Yoneda, Shigekazu, additional, Young, Edward D., additional, Yui, Hiroharu, additional, Zhang, Ai-Cheng, additional, Nakamura, Tomoki, additional, Naraoka, Hiroshi, additional, Noguchi, Takaaki, additional, Okazaki, Ryuji, additional, Sakamoto, Kanako, additional, Yabuta, Hikaru, additional, Abe, Masanao, additional, Miyazaki, Akiko, additional, Nakato, Aiko, additional, Nishimura, Masahiro, additional, Okada, Tatsuaki, additional, Yada, Toru, additional, Yogata, Kasumi, additional, Nakazawa, Satoru, additional, Saiki, Takanao, additional, Tanaka, Satoshi, additional, Terui, Fuyuto, additional, Tsuda, Yuichi, additional, Watanabe, Sei-ichiro, additional, Yoshikawa, Makoto, additional, Tachibana, Shogo, additional, and Yurimoto, Hisayoshi, additional

Published
2022
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35. Presolar Stardust in Asteroid Ryugu

Author

Barosch, Jens, primary, Nittler, Larry R., additional, Wang, Jianhua, additional, O’D. Alexander, Conel M., additional, De Gregorio, Bradley T., additional, Engrand, Cécile, additional, Kebukawa, Yoko, additional, Nagashima, Kazuhide, additional, Stroud, Rhonda M., additional, Yabuta, Hikaru, additional, Abe, Yoshinari, additional, Aléon, Jérôme, additional, Amari, Sachiko, additional, Amelin, Yuri, additional, Bajo, Ken-ichi, additional, Bejach, Laure, additional, Bizzarro, Martin, additional, Bonal, Lydie, additional, Bouvier, Audrey, additional, Carlson, Richard W., additional, Chaussidon, Marc, additional, Choi, Byeon-Gak, additional, Cody, George D., additional, Dartois, Emmanuel, additional, Dauphas, Nicolas, additional, Davis, Andrew M., additional, Dazzi, Alexandre, additional, Deniset-Besseau, Ariane, additional, Di Rocco, Tommaso, additional, Duprat, Jean, additional, Fujiya, Wataru, additional, Fukai, Ryota, additional, Gautam, Ikshu, additional, Haba, Makiko K., additional, Hashiguchi, Minako, additional, Hibiya, Yuki, additional, Hidaka, Hiroshi, additional, Homma, Hisashi, additional, Hoppe, Peter, additional, Huss, Gary R., additional, Ichida, Kiyohiro, additional, Iizuka, Tsuyoshi, additional, Ireland, Trevor R., additional, Ishikawa, Akira, additional, Ito, Motoo, additional, Itoh, Shoichi, additional, Kamide, Kanami, additional, Kawasaki, Noriyuki, additional, David Kilcoyne, A. L., additional, Kita, Noriko T., additional, Kitajima, Kouki, additional, Kleine, Thorsten, additional, Komatani, Shintaro, additional, Komatsu, Mutsumi, additional, Krot, Alexander N., additional, Liu, Ming-Chang, additional, Martins, Zita, additional, Masuda, Yuki, additional, Mathurin, Jérémie, additional, McKeegan, Kevin D., additional, Montagnac, Gilles, additional, Morita, Mayu, additional, Mostefaoui, Smail, additional, Motomura, Kazuko, additional, Moynier, Frédéric, additional, Nakai, Izumi, additional, Nguyen, Ann N., additional, Ohigashi, Takuji, additional, Okumura, Taiga, additional, Onose, Morihiko, additional, Pack, Andreas, additional, Park, Changkun, additional, Piani, Laurette, additional, Qin, Liping, additional, Quirico, Eric, additional, Remusat, Laurent, additional, Russell, Sara S., additional, Sakamoto, Naoya, additional, Sandford, Scott A., additional, Schönbächler, Maria, additional, Shigenaka, Miho, additional, Suga, Hiroki, additional, Tafla, Lauren, additional, Takahashi, Yoshio, additional, Takeichi, Yasuo, additional, Tamenori, Yusuke, additional, Tang, Haolan, additional, Terada, Kentaro, additional, Terada, Yasuko, additional, Usui, Tomohiro, additional, Verdier-Paoletti, Maximilien, additional, Wada, Sohei, additional, Wadhwa, Meenakshi, additional, Wakabayashi, Daisuke, additional, Walker, Richard J., additional, Yamashita, Katsuyuki, additional, Yamashita, Shohei, additional, Yin, Qing-Zhu, additional, Yokoyama, Tetsuya, additional, Yoneda, Shigekazu, additional, Young, Edward D., additional, Yui, Hiroharu, additional, Zhang, Ai-Cheng, additional, Abe, Masanao, additional, Miyazaki, Akiko, additional, Nakato, Aiko, additional, Nakazawa, Satoru, additional, Nishimura, Masahiro, additional, Okada, Tatsuaki, additional, Saiki, Takanao, additional, Tanaka, Satoshi, additional, Terui, Fuyuto, additional, Tsuda, Yuichi, additional, Watanabe, Sei-ichiro, additional, Yada, Toru, additional, Yogata, Kasumi, additional, Yoshikawa, Makoto, additional, Nakamura, Tomoki, additional, Naraoka, Hiroshi, additional, Noguchi, Takaaki, additional, Okazaki, Ryuji, additional, Sakamoto, Kanako, additional, Tachibana, Shogo, additional, and Yurimoto, Hisayoshi, additional

Published
2022
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36. Oxygen isotopes of anhydrous primary minerals show kinship between asteroid Ryugu and comet 81P/Wild2

Author

1000050770278, Kawasaki, Noriyuki, Nagashima, Kazuhide, Sakamoto, Naoya, Matsumoto, Toru, Bajo, Ken-Ichi, Wada, Sohei, Igami, Yohei, Miyake, Akira, Noguchi, Takaaki, Yamamoto, Daiki, Russell, Sara S., Abe, Yoshinari, Aleon, Jerome, Alexander, Conel M. O'd, Amari, Sachiko, Amelin, Yuri, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard W., Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew M., Di Rocco, Tommaso, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary R., Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Ito, Motoo, Itoh, Shoichi, Kita, Noriko T., Kitajima, Kouki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander N., Liu, Ming-Chang, Masuda, Yuki, McKeegan, Kevin D., Morita, Mayu, Motomura, Kazuko, Moynier, Frederic, Nakai, Izumi, Nguyen, Ann, Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Schonbachler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wadhwa, Meenakshi, Walker, Richard J., Yamashita, Katsuyuki, Yin, Qing-Zhu, Yokoyama, Tetsuya, Yoneda, Shigekazu, Young, Edward D., Yui, Hiroharu, Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-Ichiro, Yoshikawa, Makoto, Tachibana, Shogo, Yurimoto, Hisayoshi, 1000050770278, Kawasaki, Noriyuki, Nagashima, Kazuhide, Sakamoto, Naoya, Matsumoto, Toru, Bajo, Ken-Ichi, Wada, Sohei, Igami, Yohei, Miyake, Akira, Noguchi, Takaaki, Yamamoto, Daiki, Russell, Sara S., Abe, Yoshinari, Aleon, Jerome, Alexander, Conel M. O'd, Amari, Sachiko, Amelin, Yuri, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard W., Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew M., Di Rocco, Tommaso, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary R., Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Ito, Motoo, Itoh, Shoichi, Kita, Noriko T., Kitajima, Kouki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander N., Liu, Ming-Chang, Masuda, Yuki, McKeegan, Kevin D., Morita, Mayu, Motomura, Kazuko, Moynier, Frederic, Nakai, Izumi, Nguyen, Ann, Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Schonbachler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wadhwa, Meenakshi, Walker, Richard J., Yamashita, Katsuyuki, Yin, Qing-Zhu, Yokoyama, Tetsuya, Yoneda, Shigekazu, Young, Edward D., Yui, Hiroharu, Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-Ichiro, Yoshikawa, Makoto, Tachibana, Shogo, and Yurimoto, Hisayoshi

Abstract

The extraterrestrial materials returned from asteroid (162173) Ryugu consist predominantly of low-temperature aqueously formed secondary minerals and are chemically and mineralogically similar to CI (Ivuna-type) carbonaceous chondrites. Here, we show that high-temperature anhydrous primary minerals in Ryugu and CI chondrites exhibit a bimodal distribution of oxygen isotopic compositions: 16O-rich (associated with refractory inclusions) and 16O-poor (associated with chondrules). Both the 16O-rich and 16O-poor minerals probably formed in the inner solar protoplanetary disk and were subsequently transported outward. The abundance ratios of the 16O-rich to 16O-poor minerals in Ryugu and CI chondrites are higher than in other carbonaceous chondrite groups but are similar to that of comet 81P/Wild2, suggesting that Ryugu and CI chondrites accreted in the outer Solar System closer to the accretion region of comets.

Published
2022

37. Contribution of Ryugu-like material to Earth's volatile inventory by Cu and Zn isotopic analysis

Author

Paquet, Marine, Moynier, Frederic, Yokoyama, Tetsuya, Dai, Wei, Hu, Yan, Abe, Yoshinari, Aleon, Jerome, O'D. Alexander, Conel M., Amari, Sachiko, Amelin, Yuri, Bajo, Ken-ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard W., Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew M., Di Rocco, Tommaso, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary R., Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Ito, Motoo, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko T., Kitajima, Kouki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander N., Liu, Ming-Chang, Masuda, Yuki, McKeegan, Kevin D., Morita, Mayu, Motomura, Kazuko, Nakai, Izumi, Nagashima, Kazuhide, Nesvorny, David, Nguyen, Ann N., Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Russell, Sara S., Sakamoto, Naoya, Schoenbaechler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard J., Yamashita, Katsuyuki, Yin, Qing-Zhu, Yoneda, Shigekazu, Young, Edward D., Yui, Hiroharu, Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-ichiro, Yoshikawa, Makoto, Tachibana, Shogo, 1000080191485, Yurimoto, Hisayoshi, Paquet, Marine, Moynier, Frederic, Yokoyama, Tetsuya, Dai, Wei, Hu, Yan, Abe, Yoshinari, Aleon, Jerome, O'D. Alexander, Conel M., Amari, Sachiko, Amelin, Yuri, Bajo, Ken-ichi, Bizzarro, Martin, Bouvier, Audrey, Carlson, Richard W., Chaussidon, Marc, Choi, Byeon-Gak, Dauphas, Nicolas, Davis, Andrew M., Di Rocco, Tommaso, Fujiya, Wataru, Fukai, Ryota, Gautam, Ikshu, Haba, Makiko K., Hibiya, Yuki, Hidaka, Hiroshi, Homma, Hisashi, Hoppe, Peter, Huss, Gary R., Ichida, Kiyohiro, Iizuka, Tsuyoshi, Ireland, Trevor R., Ishikawa, Akira, Ito, Motoo, Itoh, Shoichi, Kawasaki, Noriyuki, Kita, Noriko T., Kitajima, Kouki, Kleine, Thorsten, Komatani, Shintaro, Krot, Alexander N., Liu, Ming-Chang, Masuda, Yuki, McKeegan, Kevin D., Morita, Mayu, Motomura, Kazuko, Nakai, Izumi, Nagashima, Kazuhide, Nesvorny, David, Nguyen, Ann N., Nittler, Larry, Onose, Morihiko, Pack, Andreas, Park, Changkun, Piani, Laurette, Qin, Liping, Russell, Sara S., Sakamoto, Naoya, Schoenbaechler, Maria, Tafla, Lauren, Tang, Haolan, Terada, Kentaro, Terada, Yasuko, Usui, Tomohiro, Wada, Sohei, Wadhwa, Meenakshi, Walker, Richard J., Yamashita, Katsuyuki, Yin, Qing-Zhu, Yoneda, Shigekazu, Young, Edward D., Yui, Hiroharu, Zhang, Ai-Cheng, Nakamura, Tomoki, Naraoka, Hiroshi, Noguchi, Takaaki, Okazaki, Ryuji, Sakamoto, Kanako, Yabuta, Hikaru, Abe, Masanao, Miyazaki, Akiko, Nakato, Aiko, Nishimura, Masahiro, Okada, Tatsuaki, Yada, Toru, Yogata, Kasumi, Nakazawa, Satoru, Saiki, Takanao, Tanaka, Satoshi, Terui, Fuyuto, Tsuda, Yuichi, Watanabe, Sei-ichiro, Yoshikawa, Makoto, Tachibana, Shogo, 1000080191485, and Yurimoto, Hisayoshi

Abstract

Initial analyses showed that asteroid Ryugu's composition is close to CI (Ivuna-like) carbonaceous chondrites (CCs) - the chemically most primitive meteorites, characterized by near-solar abundances for most elements. However, some isotopic signatures (for example, Ti, Cr) overlap with other CC groups, so the details of the link between Ryugu and the CI chondrites are not yet fully clear. Here we show that Ryugu and CI chondrites have the same zinc and copper isotopic composition. As the various chondrite groups have very distinct Zn and Cu isotopic signatures, our results point at a common genetic heritage between Ryugu and CI chondrites, ruling out any affinity with other CC groups. Since Ryugu's pristine samples match the solar elemental composition for many elements, their Zn and Cu isotopic compositions likely represent the best estimates of the solar composition. Earth's mass-independent Zn isotopic composition is intermediate between Ryugu/CC and non-carbonaceous chondrites (NCs), suggesting a contribution of Ryugu-like material to Earth's budgets of Zn and other moderately volatile elements.

Published
2022

42. Stock options rules in Malaysia and Japan: a comparative analysis

Author

Yamashita, Katsuyuki, Hanefah, Hajah Mustafa bin Mohd, and Noguchi, Akihiro

Subjects
Employee stock options -- Laws, regulations and rules, Securities law -- Evaluation, Executives -- Compensation and benefits, Executives -- Laws, regulations and rules, Government regulation, Business, international
Abstract

As each country has its own rules of the society based on its own history and culture, introduction of new accounting standards will have different effect among countries. IFRS 2 Share-based Payment affected accounting standards in Malaysia and Japan. FRS 2 in Malaysia and ASBJ Statement 8 in Japan both adopted modified grant date fair value accounting for stock options. But the situation of stock option plans, not only before, but also after the adoption of modified grant date fair value accounting, are different between Malaysia and Japan. In Malaysia, although the culture is different from the USA, similar reaction was observed. In Japan, different reaction, namely, shift toward restricted stock type stock option plan was observed. In this paper, history of accounting, taxation, and law are compared and analyzed to clarify that the difference of the rules in each society affects the outcome of new accounting standards., INTRODUCTION In the USA, Baker (1940) analyzed the stock options used as a form of executive compensation in late 1920s to 1930s. As for accounting treatment for employee stock options, [...]

Published
2010

43. Chemical separation and mass spectrometry of Cr, Fe, Ni, Zn, and Cu in terrestrial and extraterrestrial materials using thermal ionization mass spectrometry

Author

Yamakawa, Akane, Yamashita, Katsuyuki, Makishima, Akio, and Nakamura, Eizo

Subjects
Mass spectrometry -- Usage, Separation (Technology) -- Usage, Transition metals -- Chemical properties, Transition metals -- Research, Chemistry
Abstract

A sequential chemical separation technique for Cr, Fe, Ni, Zn, and Cu in terrestrial and extraterrestrial silicate rocks was developed for precise and accurate determination of elemental concentration by the isotope dilution method (ID). The technique uses a combination of cation-anion exchange chromatography and Eichrom nickel specific resin. The method was tested using a variety of matrixes including bulk meteorite (Allende), terrestrial peridotite (JP-1), and basalt (JB-lb). Concentrations of each element was determined by thermal ionization mass spectrometry (TIMS) using W filaments and a Si-B-AI type activator for Cr, Fe, Ni, and Zn and a Re filament and silicic acid-H3PO4 activator for Cu. The method can be used to precisely determine the concentrations of these elements in very small silicate samples, including meteorites, geochemical reference samples, and mineral standards for microprobe analysis. Furthermore, the Cr mass spectrometry procedure developed in this study can be extended to determine the isotopic ratios of [sup.53]Cr/[sup.52]Cr and [sup.54]Cr/[sup.52]Cr with precision of ~0.05[epsilon] and ~0.10[epsilon] (1[epsilon] = 0.01%), respectively, enabling cosmochemical applications such as high precision Mn-Cr chronology and investigation of nucleosynthetic isotopic anomalies in meteorites. 10.1021/ac901762a

Published
2009

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