研究者詳細 - 中川　亜紀治

論文 - 中川　亜紀治

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Nakagawa, Akiharu ; Kurayama, Tomoharu ; Sudou, Hiroshi ; Orosz, Gabor . Implication of the period-magnitude relation for massive AGB stars and its astronomical applications . Proceedings of the IAU symposium 376, At the cross-roads of astrophysics and cosmology 2024年2月招待査読

Tachibana K., Miyata T., Kamizuka T., Ohsawa R., Takita S., Nakagawa A., Ita Y., Uchiyama M. . Investigation of mid-infrared long-Term variability of dusty AGB stars using multi-epoch scan data of AKARI and WISE . Publications of the Astronomical Society of Japan75 ( 3 ) 489 - 498 2023年6月

記述言語：日本語出版者・発行元：Publications of the Astronomical Society of Japan

Asymptotic giant branch (AGB) stars are one of the main sources of dust in the Universe. They form and supply dust triggered by stellar pulsations, but the details of the mechanism are still unknown. Among all AGB stars, dusty AGB stars are the most important in terms of dust supply because they contain the star with a high mass-loss rate. To investigate the relationship between the pulsation and the dust supply for such dusty AGB stars, long-Term mid-infrared monitoring is necessary. In this study, we combine data from a infrared astronomical satellites AKARI and WISE to generate mid-infrared long-Term observation data. This collected data enables us to investigate the variability of dusty AGB stars with a variability period of more than several hundred days (>250 d). Furthermore, we determine the mid-infrared variability amplitudes of 169 O-rich AGB stars and 28 OH/IR stars in our Galaxy, as well as data at other wavelengths. This study is the largest study on mid-infrared variability. Additionally, we discover a positive correlation between the variability amplitude A18μm in the 18μm band and the W3W4 infrared color which is the measure of the dust supply. Also, we find that this relationship is independent of the variability period and mode. Finally, we calculate the radiative transfer of circumstellar dust from AGB stars. The result of our calculations showed that $A_{18\mu \rm {m} is strongly affected by the luminosity change ratio of the central star. These experimental results imply that the luminosity change ratio has a strong influence on the dust supply of AGB star.

DOI： 10.1093/pasj/psac088

Scopus

Tachibana, Kengoほか . Investigation of mid-infrared long-term variability of dusty AGB stars using multi-epoch scan data of AKARI and WISE . Publications of the Astronomical Society of Japan75 ( 3 ) 489 - 498 2023年6月査読

Nakagawa, Akiharu ; Morita, Atsushi ; Sakai, Nobuyuki ; Kurayama, Tomoharu ; Sudou, Hiroshi ; Orosz, Gabor ; Yuda, Akito ; Kaseda, Daichi ; Matsuno, Masako ; Hamada, Shota ; Omodaka, Toshihiro ; Ueno, Yuji ; Shibata, Katsunori M. ; Tamura, Yoshiaki ; Jike, Takaaki ; Hirano, Ken ; Honma, Mareki . Astrometric VLBI observations of H2O masers in an extreme OH/IR star candidate NSV 17351 . PASJ : publications of the Astronomical Society of Japan75 ( 3 ) 529 - 545 2023年4月査読

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Astronomical Society of Japan

The results of astrometric very long baseline interferometry (VLBI) observations toward an extreme OH/IR star candidate NSV 17351 are presented. Using the VERA (VLBI Exploration of Radio Astrometry) VLBI array, we observed 22 GHz H2O masers of NSV 17351 and derived an annual parallax of 0.247 ± 0.035 mas, which corresponds to a distance of 4.05 ± 0.59 kpc, from the observation. By averaging proper motions of 15 maser spots further, we determined the systemic proper motion of NSV 17351 to be (μαcos δ, μδ)avg. = (-1.19 ± 0.11, 1.30 ± 0.19) mas yr-1. The maser spots spread out over a region of 20 × 30 mas, which can be converted to a spatial distribution of ∼80 × 120 au at the source distance. Internal motions of the maser spots suggest an outward-moving maser region with respect to the estimated position of the central star. From single-dish monitoring of the H2O maser emission, we estimate the pulsation period of NSV 17351 to be 1122 ± 24 d. This is the first report of the periodic activity of NSV 17351, indicating that NSV 17351 could have a mass of ∼4 MS. We confirmed that the time variation of H2O masers can be used as a period estimator of variable OH/IR stars. Furthermore, by inspecting dozens of double-peaked H2O maser spectra for the last 40 years, we discovered the long-Term acceleration in the radial velocity of the circumstellar matter to be 0.17 ± 0.03 km s-1 yr-1. We finally determined the position and kinematics in the Milky Way Galaxy and found that NSV 17351 is located in an interarm region between the Outer and Perseus arms. We note that the astrometric VLBI observation toward extreme OH/IR stars shows us a useful sample of the Galactic dynamics.

DOI： 10.1093/pasj/psad019

Scopus

CiNii Research

Honma M., Hirota T., Hachisuka K., Imai H., Kobayashi H., Jike T., Nakagawa A., Oyama T., Sunada K., Sakai D., Sakai N., Yamauchi A. . Galactic maser astrometry with VERA . Proceedings of the International Astronomical Union18 82 - 87 2022年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Proceedings of the International Astronomical Union

VERA has been regularly conducting astrometry of Galactic maser sources for ∼ 20 years, producing more than 100 measurements of parallaxes and proper motions of star-forming regions as well as AGB stars. By combining the observational results obtained by VLBA BeSSeL, EVN, and LBA, maser astrometry provides a unique opportunity to explore the fundamental structure of the Galaxy. Here we present the view of the Galaxy revealed by the maser astrometry, and also discuss the importance of maser astrometry in the era of GAIA by comparing the results obtained by VLBI and GAIA. We also present our view of “proper motions toward the future” of the relevant field, expected in the next decade based on global collaborations.

DOI： 10.1017/S174392132300306X

Scopus

Nakagawa A., Kurayama T., Sudou H., Orosz G. . Properties of pulsating OH/IR stars revealed from astrometric VLBI observation . Proceedings of the International Astronomical Union18 300 - 308 2022年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Proceedings of the International Astronomical Union

We aim to reveal properties of evolution stages in AGB phase; Mira, OH/IR stars, and non-variable OH/IR stars. We presented results of our VLBI observations of four stars; NSV17351, OH39.7+1.5, IRC-30363, and AW Tau. We used the VERA VLBI array to observe 22 GHz H2O masers. Parallaxes of the four sources were obtained to be 0.247±0.035 mas (4.05±0.59 kpc), 0.54±0.03 mas (1.85±0.10 kpc), 0.562±0.201 mas (1.78±0.73 kpc), and 0.449±0.032 mas (2.23±0.16 kpc). Determination of pulsation period of NSV17351 was done for the first time. We revealed the position and kinematics of NSV17351 in our Galaxy and found that NSV17351 is located in an interarm region. A new period-magnitude relationship was indicated in the infrared region. Various other properties based on the distance measurements are also discussed. We have to emphasize that the VLBI astrometry is effective and the only way for parallax measurements of dust obscured OH/IR stars.

DOI： 10.1017/S174392132300296X

Scopus

Akahori, Takuya ; Imai, Hiroshi ; Eie, Sujin ; Oyama, Tomoaki ; Kimura, Kimihiro ; Kurayama, Tomoharu ; Kono, Yusuke ; Kobayashi, Hideyuki ; Sakai, Daisuke ; Sakai, Nobuyuki ; Teraya, Takaaki ; Jike, Takaaki ; Motogi, Kazuhito ; Sugiyama, Koichiro ; Sudo, Hiroshi ; Takefuji, Kazuhiro ; Kino, Motoki ; Doi, Akihiro ; Nagai, Hiroshi ; Nagayama, Takumi 他 . VLBI Future Planning Working Group Review Report . VLBI Future Planning Working Group Review Report, June 2021, 4th Edition 2021年6月国際共著

Masako Matsuno, Akiharu Nakagawa, Atsushi Morita, Tomoharu Kurayama, Toshihiro Omodaka, Takumi Nagayama, Mareki Honma, Katsunori M Shibata, Yuji Ueno, Takaaki Jike, Yoshiaki Tamura . Annual parallax measurement of the Mira variable star BX Camelopardalis with VERA . PASJ : publications of the Astronomical Society of Japan72 ( 4 ) 56 2020年8月査読

VERA collaboration, Tomoya Hirota, Takumi Nagayama, Mareki Honma, Yuuki Adachi, Ross A Burns, James O Chibueze, Yoon Kyung Choi, Kazuya Hachisuka, Kazuhiro Hada, Yoshiaki Hagiwara, Shota Hamada, Toshihiro Handa, Mao Hashimoto, Ken Hirano, Yushi Hirata, Takanori Ichikawa, Hiroshi Imai, Daichi Inenaga, Toshio Ishikawa, Takaaki Jike, Osamu Kameya, Daichi Kaseda, Jeong Sook Kim, Jungha Kim, Mi Kyoung Kim, Hideyuki Kobayashi, Yusuke Kono, Tomoharu Kurayama, Masako Matsuno, Atsushi Morita, Kazuhito Motogi, Takeru Murase, Akiharu Nakagawa, Hiroyuki Nakanishi, Kotaro Niinuma, Junya Nishi, Chung Sik Oh, Toshihiro Omodaka, Miyako Oyadomari, Tomoaki Oyama, Daisuke Sakai, Nobuyuki Sakai, Satoko Sawada-Satoh, Katsunori M Shibata, Makoto Shizugami, Jumpei Sudo, Koichiro Sugiyama, Kazuyoshi Sunada, Syunsaku Suzuki, Ken Takahashi, Yoshiaki Tamura, Fumie Tazaki, Yuji Ueno, Yuri Uno, Riku Urago, Koji Wada, Yuan Wei Wu, Kazuyoshi Yamashita, Yuto Yamashita, Aya Yamauchi, Akito Yuda . The First VERA Astrometry Catalog . PASJ : publications of the Astronomical Society of Japan72 ( 4 ) 2020年8月査読

Takumi Nagayama, Hideyuki Kobayashi, Tomoya Hirota, Mareki Honma, Takaaki Jike, Mi Kyoung Kim, Akiharu Nakagawa, Toshihiro Omodaka, Tomoaki Oyama, Daisuke Sakai, Katsunori M Shibata, Yoshiaki Tamura . Performance of VERA in 10 micro-arcsecond astrometry . PASJ : publications of the Astronomical Society of Japan72 ( 4 ) 2020年8月査読

Riku Urago, Ryohei Yamaguchi, Toshihiro Omodaka, Takumi Nagayama, James O Chibueze, Masayuki Y Fujimoto, Takahiro Nagayama, Akiharu Nakagawa, Yuji Ueno, Miho Kawabata, Tatsuya Nakaoka, Kengo Takagi, Masayuki Yamanaka, Koji Kawabata . Trigonometric parallax of O-rich Mira variable star OZ Gem (IRAS 07308+3037): A confirmation of the difference between the P-L relations of the Large Magellanic Cloud and the Milky Way . PASJ : publications of the Astronomical Society of Japan72 ( 4 ) 2020年8月査読

Hiroshi Imai, Yuri Uno, Daichi Maeyama, Ryosuke Yamaguchi, Kei Amada, Yuhki Hamae, Gabor Orosz, Jose F Gomez, Daniel Tafoya, Lucero Uscanga, Ross A Burns . FLASHING: New high-velocity H2O masers in IRAS 18286-0959 . PASJ : publications of the Astronomical Society of Japan72 ( 4 ) 2020年8月査読

James O Chibueze, Riku Urago, Toshihiro Omodaka, Yuto Morikawa, Masayuki Y Fujimoto, Akiharu Nakagawa, Takahiro Nagayama, Takumi Nagayama, Ken Hirano . Astrometry and infrared observations of the Mira variable stars AP Lyncis, V837 Herculis, and BX Camelopardalis: Implications for the period-luminosity relation of the Milky Way . PASJ : publications of the Astronomical Society of Japan72 ( 4 ) 59 2020年8月査読

Imai, Hiroshi ; Nakagawa, Akiharu ; Takaba, Hiroshi . Overall variation of the H2O masers around W Hydrae in 28 years . PASJ : publications of the Astronomical Society of Japan71 ( 6 ) 120 2019年12月査読

Koide, Nagito ; Nakanishi, Hiroyuki ; Sakai, Nobuyuki ; Habe, Asao ; Shima, Kazuhiro ; Kurayama, Tomoharu ; Matsuo, Mitsuhiro ; Tezuka, Daisuke ; Kurahara, Kohei ; Ueno, Saeko ; Burns, Ross A. ; Nakagawa, Akiharu ; Honma, Mareki ; Shibata, Katsunori M. ; Nagayama, Takumi ; Kawaguchi, Noriyuki . Outer rotation curve of the Galaxy with VERA. IV. Astrometry of IRAS 01123+6430 and the possibility of cloud-cloud collision . PASJ : publications of the Astronomical Society of Japan71 ( 6 ) 113 2019年12月査読

Nakagawa, Akiharu ; Kurayama, Tomoharu ; Orosz, Gabor ; Oyama, Tomoaki ; Nagayama, Takumi ; Omodaka, Toshihiro . Astrometric observation of the Galactic LPVs with VERA; Mira and OH/IR stars . 343 476 - 477 2019年12月

Chibueze, James O. search by orcid ; Omodaka, Toshihiro ; Urago, Riku ; Nagayama, Takumi ; Alhassan, Jibrin A. ; Nishida, Yoshiro ; Aralu, Ogochukwu U. ; van Rooyen, Ruby ; Nakagawa, Akiharu ; Honma, Mareki ; Ueno, Yuji . Annual parallax and galactic orbit of Y Librae (IRAS 15090-0549) Mira variable star-GALORB release . PASJ : publications of the Astronomical Society of Japan71 ( 5 ) 92 2019年10月査読

Sudou, Hiroshi ; Omodaka, Toshihiro ; Murakami, Kotone ; Nagayama, Takahiro ; Nakagawa, Akiharu ; Urago, Riku ; Nagayama, Takumi ; Hirano, Ken ; Honma, Mareki . Annual parallax measurements of a semi-regular variable star SV Pegasus with VERA . PASJ : publications of the Astronomical Society of Japan71 ( 1 ) 16 2019年1月査読

Van Langevelde, H. ; Quiroga-Nunez, L. H. ; Vlemmings, W. H. T. ; Loinard, L. ; Honma, M. ; Nakagawa, A. ; Immer, K. ; Burns, R. A. ; Pihlstrom, Y. ; Sjouwerman, L. ; Natarajan, I. ; Rich, R. M. ; Deane, R . The Synergy between VLBI and Gaia astrometry . 14th European VLBI Network Symposium & Users Meeting (EVN 2018) 43 2018年11月

Honma, Mareki ; Nagayama, Takumi ; Hirota, Tomoya ; Sakai, Nobuyuki ; Oyama, Tomoaki ; Yamauchi, Aya ; Ishikawa, Toshiaki ; Handa, Toshihiro ; Hirano, Ken ; Imai, Hiroshi ; Jike, Takaaki ; Kameya, Osamu ; Kono, Yusuke ; Kobayashi, Hideyuki ; Nakagawa, Akiharu ; Shibata, Katsunori M. ; Sakai, Daisuke ; Sunada, Kazuyoshi ; Sugiyama, Koichiro ; Sato, Katsuhisa Omodaka, Toshihiro ; Tamura, Yoshiaki ; Ueno, Yuji . Maser Astrometry and Galactic Structure Study with VLBI . Astrophysical Masers: Unlocking the Mysteries of the Universe, Proceedings of the International Astronomical Union, IAU Symposium, Volume 336336 162 - 167 2018年8月

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