2021/08/04 更新

写真a

シンナガ ヒロコ
新永 浩子
Hiroko Shinnaga
所属
理工学域理学系 理工学研究科(理学系) 理学専攻 物理・宇宙プログラム 准教授
職名
准教授
外部リンク

学位

  • 博士(理学) ( 1999年3月   茨城大学 )

研究キーワード

  • 星間・星周物理学;磁場観測;分光偏波観測;サブミリ波天文学;電波天文学

研究分野

  • 自然科学一般 / 天文学  / 星間物理学;星形成;星の進化;宇宙メーザー;宇宙磁場

経歴

  • 鹿児島大学   理工学域理学系 理工学研究科(理学系) 理学専攻 物理・宇宙プログラム   准教授

    2020年4月 - 現在

  • National Radio Astronomy Observatory   Socorro Campus   Visiting Scholar

    2016年7月 - 2017年2月

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    国名:アメリカ合衆国

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  •   Graduate School of Science and Engineering   Associate Professor

    2014年12月 - 現在

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    国名:日本国

  • 鹿児島大学   理工学域理学系 理工学研究科(理学系) 物理・宇宙専攻   准教授

    2014年12月 - 2020年3月

  • 鹿児島大学   大学院理工学研究科(理学系)   准教授

    2014年 - 現在

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    国名:日本国

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  •   Chile Observatory East Asia ALMA Regional Center   Project Associate Professor

    2013年4月 - 2014年11月

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    国名:日本国

  • ハワイ大学   ハワイ大学ヒロ校   兼任教員

    2012年8月 - 2012年12月

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    国名:アメリカ合衆国

  •   Subaru Telescope   Postdoc fellow

    2012年5月 - 2012年12月

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    国名:日本国

  • ハワイ大学ヒロ校   兼任教員

    2012年

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    国名:アメリカ合衆国

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  • カリフォルニア工科大学   サブミリ波天文台   常勤リサーチサイエンティスト

    2004年9月 - 2012年7月

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    国名:アメリカ合衆国

  • カリフォルニア工科大学   サブミリ波天文台   常勤リサーチサイエンティスト

    2004年 - 2012年

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    国名:アメリカ合衆国

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  • ハーバード大学観測所ースミソニアン天体物理観測所   天体物理学センター   博士後研究員

    2002年9月 - 2004年8月

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    国名:アメリカ合衆国

  • ハーバード大学ースミソニアン天体物理研究所   天体物理学研究センター   ポスドクフェロー

    2001年 - 2004年

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    国名:アメリカ合衆国

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  • 中央研究院   天文及天文物理研究所   博士後研究員

    1999年 - 2001年

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    国名:台湾

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▼全件表示

所属学協会

  • 日本学術会議

    2017年10月 - 現在

  • アメリカ天文学会

    2005年9月 - 現在

  • 日本天文学会

    1992年4月 - 現在

  • 国際天文学連合

    2005年9月 - 現在

  • 宇宙電波懇談会

    1992年4月 - 現在

委員歴

  • 日本天文学会   男女共同参画委員  

    2021年 - 現在   

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    団体区分:学協会

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  • 科学者委員会研究計画研究資金検討分科会   物理学分野 大型研究計画評価小分科会 委員  

    2019年4月 - 2020年1月   

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    団体区分:学協会

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  • 日本学術会議   連携会員  

    2017年 - 現在   

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    団体区分:政府

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留学歴

  • 2016年7月 - 2017年2月   米国国立電波天文台   若手教員海外研修

  • 2012年8月 - 2012年12月   ハワイ大学ヒロ校   兼任講師

  • 2004年9月 - 2012年7月   カリフォルニア工科大学 サブミリ波天文台   常勤リサーチサイエンティスト

  • 2001年9月 - 2004年8月   ハーバード大学観測所ースミソニアン天体物理観測所 天体物理学センター   博士後研究員

  • 1999年7月 - 2001年8月   中央研究院(台湾)   博士後研究員

 

論文

  • Hiroko Shinnaga, Mark J. Claussen, Satoshi Yamamoto, Masumi Shimojo .  Strong magnetic field generated by the extreme oxygen-rich red supergiant VY Canis Majoris .  Publication of Astronomical Society of Japan69 ( 6 ) 1 - 6   2017年12月査読

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    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:Oxford University Press  

    その他リンク: https://academic.oup.com/pasj/advance-article/doi/10.1093/pasj/psx110/4638328?guestAccessKey=eba6647c-5eba-4b08-8432-9a3dece2bb58

  • Hiroko Shinnaga, Giles Novak, John E. Vaillancourt, Masahiro N. Machida et al. .  Magnetic Field in the Isolated Massive Dense Clump IRAS 20126+4104 .  The Astrophysical Journal Letters750 ( L29 ) 1 - 5   2012年1月査読

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    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:IOP Science  

    arXiv

    その他リンク: http://iopscience.iop.org/article/10.1088/2041-8205/750/2/L29/meta;jsessionid=E8E6C1A34EE44B592F968195BAB7F3C7.c3.iopscience.cld.iop.org

  • R. S. Furuya, R. Cesaroni, and H. Shinnaga .  Infall, outflow, and rotation in the G19.61-0.23 hot molecular core .  Astronomy and Astrophysics525 ( A72 ) 1 - 18   2011年1月査読

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:EDP Sciences  

    arXiv

    その他リンク: http://www.aanda.org/articles/aa/abs/2011/01/aa14402-10/aa14402-10.html

  • Hiroko Shinnaga, Thomas G. Phillips, Ray S. Furuya, and Yoshimi Kitamura .  Warm Extended Dense Gas at the Heart of a Cold Collapsing Dense Core .  The Astrophysical Journal Letters706   L226 - L229   2009年1月査読

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    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:IOP Science  

    arXiv

    その他リンク: http://iopscience.iop.org/article/10.1088/0004-637X/706/2/L226/meta

  • M. Krejny, T. G. Matthews, G. Novak, J. Cho, H. Li, H. Shinnaga et al. .  Polarimetry of DG TAU at 350 μm .  The Astrophysical Journal705   717 - 722   2009年1月査読

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:IOP Science  

    arXiv

    その他リンク: http://iopscience.iop.org/article/10.1088/0004-637X/705/1/717/meta

  • R. Furuya and H. Shinnaga .  High-velocity Molecular Outflow in CO J = 7-6 Emission from the Orion Hot Core .  The Astrophysical Journal703   1198 - 1202   2009年1月査読

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:IOP Science  

    arXiv

    その他リンク: http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009ApJ...703.1198F&link_type=EJOURNAL&db_key=AST&high=

  • H. Shinnaga, K.H. Young, R.P.J. To;amis. R. Chamberlin et al. .  IRC+10216'S Innermost Envelope--The eSMA'S View .  The Astrophysical Journal698   1924 - 1933   2009年1月査読

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    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:IOP Science  

    arXiv

    その他リンク: http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009ApJ...698.1924S&link_type=EJOURNAL&db_key=AST&high=

  • R. S. Furuya, Y. Kitamurai, and H. Shinnaga .  Spectroscopic Evidence for Gas Infall in GF 9-2 .  The Astrophysical Journal Letters692   L96 - L99   2009年1月査読

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:IOP Science  

    arXiv

    その他リンク: http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009ApJ...692L..96F&link_type=EJOURNAL&db_key=AST&high=

  • Shinnaga, Hiroko; Phillips, Thomas G.; Furuya, Ray S.; Cesaroni, Riccardo .  Submillimeter Observations of the Isolated Massive Dense Clump IRAS 20126+4104 .  The Astrophysical Journal682   1103 - 1113   2008年1月査読

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    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:IOP Science  

    arXiv

    その他リンク: http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008ApJ...682.1103S&link_type=EJOURNAL&db_key=AST&high=

  • Aina Palau , Qizhou Zhang, Josep M. Girart, Junhao Liu, Ramprasad Rao, Patrick M. Koch, Robert Estalella, Huei-Ru Vivien Chen, Hauyu Baobab Liu, Keping Qiu, Zhi-Yun Li, Luis A. Zapata, Sylvain Bontemps, Paul T. P. Ho, Henrik Beuther, Tao-Chung Ching, Hiroko Shinnaga, and Aida Ahmadi .  Does the Magnetic Field Suppress Fragmentation in Massive Dense Cores? .  The Astrophysical Journal, Volume 912, Issue 2, id.159, 33 pp.912 ( 2 ) 1 - 33   2021年5月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:American Astronomical Society  

    DOI: 10.3847/1538-4357/abee1e

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    その他リンク: https://iopscience.iop.org/article/10.3847/1538-4357/abee1e/pdf

  • The JCMT BISTRO Survey: Revealing the diverse magnetic field morphologies in Taurus dense cores with sensitive sub-millimeter polarimetry .  The Astrophysical Journal Letters, Volume 912, Issue 2, id.L27, 15 pp.912 ( 2 ) 1 - 15   2021年3月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    arXiv

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    その他リンク: http://arxiv.org/pdf/2103.02219v1

  • D. Arzoumanian, R. S. Furuya, T. Hasegawa, M. Tahani, S. Sadavoy, C. L. H. Hull, D. Johnstone, P. M. Koch, S. Inutsuka, Y. Doi, T. Hoang, T. Onaka, K. Iwasaki, Y. Shimajiri, T. Inoue, N. Peretto, P. André, P. Bastien, D. Berry, H.-R. V. Chen, J. Di Francesco, C. Eswaraiah, L. Fanciullo, L. M. Fissel, J. Hwang, J.-h. Kang, G. Kim, K.-T. Kim, F. Kirchschlager, W. Kwon, C. W. Lee, H.-L. Liu, A.-R. Lyo, K. Pattle, A. Soam, X. Tang, A. Whitworth, T.-C. Ching, S. Coudé, J.-W. Wang, D. Ward-Thompson, S.-P. Lai, K. Qiu, T. L. Bourke, D.-Y. Byun, M. Chen, Z. Chen, W. P. Chen, J. Cho, Y. Choi, M. Choi, A. Chrysostomou, E. J. Chung, S. Dai, P. N. Diep, H.-Y. Duan, Y. Duan, D. Eden, J. Fiege, E. Franzmann, P. Friberg, G. Fuller, T. Gledhill, S. Graves, J. Greaves, M. Griffin, Q. Gu, I. Han, J. Hatchell, S. Hayashi, M. Houde, I.-G. Jeong, M. Kang, S.-j. Kang, A. Kataoka, K. Kawabata, F. Kemper, M.-R. Kim, K. H. Kim, J. Kim, S. Kim, J. Kirk, M. I. N. Kobayashi, V. Könyves, T. Kusune, J. Kwon, K. Lacaille, C.-Y. Law, C.-F. Lee, Y.-H. Lee, S.-S. Lee, H. Lee, J.-E. Lee, H.-b. Li, D. Li, D. L. Li, J. Liu, T. Liu, S.-Y. Liu, X. Lu, S. Mairs, M. Matsumura, B. Matthews, G. Moriarty-Schieven, T. Nagata, F. Nakamura, H. Nakanishi, N. B. Ngoc, N. Ohashi, G. Park, H. Parsons, T.-S. Pyo, L. Qian, R. Rao, J. Rawlings, M. Rawlings, B. Retter, J. Richer, A. Rigby, H. Saito, G. Savini, A. Scaife, M. Seta, H. Shinnaga, M. Tamura, Y.-W. Tang, K. Tomisaka, L. N. Tram, Y. Tsukamoto, S. Viti, H. Wang, J. Xie, H.-W. Yen, H. Yoo, J. Yuan, H.-S. Yun, T. Zenko, G. Zhang, C.-P. Zhang, Y. Zhang, J. Zhou, L. Zhu, I. de Looze, C. D. Dowell, S. Eyres, S. Falle, R. Friesen, J.-F. Robitaille, S. van Loo .  Dust polarized emission observations of NGC 6334 .  Astronomy & Astrophysics647   A78 - A78   2021年3月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:EDP Sciences  

    <italic>Context.</italic> Molecular filaments and hubs have received special attention recently thanks to new studies showing their key role in star formation. While the (column) density and velocity structures of both filaments and hubs have been carefully studied, their magnetic field (B-field) properties have yet to be characterized. Consequently, the role of B-fields in the formation and evolution of hub-filament systems is not well constrained.


    <italic>Aims.</italic> We aim to understand the role of the B-field and its interplay with turbulence and gravity in the dynamical evolution of the NGC 6334 filament network that harbours cluster-forming hubs and high-mass star formation.


    <italic>Methods.</italic> We present new observations of the dust polarized emission at 850 <italic>μ</italic>m toward the 2 pc × 10 pc map of NGC 6334 at a spatial resolution of 0.09 pc obtained with the <italic>James Clerk Maxwell</italic> Telescope (JCMT) as part of the B-field In STar-forming Region Observations (BISTRO) survey. We study the distribution and dispersion of the polarized intensity (<italic>PI</italic>), the polarization fraction (<italic>PF</italic>), and the plane-of-the-sky B-field angle (<italic>χ</italic><sub>B_POS</sub>) toward the whole region, along the 10 pc-long ridge and along the sub-filaments connected to the ridge and the hubs. We derived the power spectra of the intensity and <italic>χ</italic><sub>B<sub>POS</sub></sub> along the ridge crest and compared them with the results obtained from simulated filaments.


    <italic>Results.</italic> The observations span ~3 orders of magnitude in Stokes <italic>I</italic> and <italic>PI</italic> and ~2 orders of magnitude in <italic>PF</italic> (from ~0.2 to ~ 20%). A large scatter in <italic>PI</italic> and <italic>PF</italic> is observed for a given value of <italic>I</italic>. Our analyses show a complex B-field structure when observed over the whole region (~ 10 pc); however, at smaller scales (~1 pc), <italic>χ</italic><sub>B<sub>POS</sub></sub> varies coherently along the crests of the filament network. The observed power spectrum of <italic>χ</italic><sub>B<sub>POS</sub></sub> can be well represented with a power law function with a slope of − 1.33 ± 0.23, which is ~20% shallower than that of <italic>I</italic>. We find that this result is compatible with the properties of simulated filaments and may indicate the physical processes at play in the formation and evolution of star-forming filaments. Along the sub-filaments, <italic>χ</italic><sub>B<sub>POS</sub></sub> rotates frombeing mostly perpendicular or randomly oriented with respect to the crests to mostly parallel as the sub-filaments merge with the ridge and hubs. This variation of the B-field structure along the sub-filaments may be tracing local velocity flows of infalling matter in the ridge and hubs. Our analysis also suggests a variation in the energy balance along the crests of these sub-filaments, from magnetically critical or supercritical at their far ends to magnetically subcritical near the ridge and hubs. We also detect an increase in <italic>PF</italic> toward the high-column density (<italic>N</italic><sub>H<sub>2</sub></sub> ≳ 10<sup>23</sup> cm<sup>−2</sup>) star cluster-forming hubs. These latter large <italic>PF</italic> values may be explained by the increase in grain alignment efficiency due to stellar radiation from the newborn stars, combined with an ordered B-field structure.


    <italic>Conclusions.</italic> These observational results reveal for the first time the characteristics of the small-scale (down to ~ 0.1 pc) B-field structure of a 10 pc-long hub-filament system. Our analyses show variations in the polarization properties along the sub-filaments that may be tracing the evolution of their physical properties during their interaction with the ridge and hubs. We also detect an impact of feedback from young high-mass stars on the local B-field structure and the polarization properties, which could put constraints on possible models for dust grain alignment and provide important hints as to the interplay between the star formation activity and interstellar B-fields.

    DOI: 10.1051/0004-6361/202038624

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  • Rachel E. Harrison, Leslie W. Looney, Ian W. Stephens, Zhi-Yun Li, Richard Teague, Richard M. Crutcher, Haifeng Yang, Erin Cox, Manuel Fernández-López, Hiroko Shinnaga .  ALMA CN Zeeman Observations of AS 209: Limits on Magnetic Field Strength and Magnetically Driven Accretion Rate .      2021年1月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    While magnetic fields likely play an important role in driving the evolution
    of protoplanetary disks through angular momentum transport, observational
    evidence of magnetic fields has only been found in a small number of disks.
    Although dust continuum linear polarization has been detected in an increasing
    number of disks, its pattern is more consistent with that from dust scattering
    than from magnetically aligned grains in the vast majority of cases. Continuum
    linear polarization from dust grains aligned to a magnetic field can reveal
    information about the magnetic field's direction, but not its strength. On the
    other hand, observations of circular polarization in molecular lines produced
    by Zeeman splitting offer a direct measure of the line-of-sight magnetic field
    strength in disks. We present upper limits on the net toroidal and vertical
    magnetic field strengths in the protoplanetary disk AS 209 derived from Zeeman
    splitting observations of the CN 2-1 line. The 3$\sigma$ upper limit on the net
    line-of-sight magnetic field strength in AS 209 is 5.0 mG on the redshifted
    side of the disk and 4.2 mG on the blueshifted side of the disk. Given the
    disk's inclination angle, we set a 3$\sigma$ upper limit on the net toroidal
    magnetic field strength of 8.7 and 7.3 mG for the red and blue sides of the
    disk, respectively, and 6.2 and 5.2 mG on the net vertical magnetic field on
    the red and blue sides of the disk. If magnetic disk winds are a significant
    mechanism of angular momentum transport in the disk, magnetic fields of a
    strength close to the upper limits would be sufficient to drive accretion at
    the rate previously inferred for regions near the protostar.

    DOI: 10.3847/1538-4357/abd94e

    arXiv

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    その他リンク: http://arxiv.org/pdf/2101.01846v1

  • Ken'ichi Tatematsu, Gwanjeong Kim, Tie Liu, Neal J. Evans II, Hee-Weon Yi, Jeong-Eun Lee, Yuefang Wu, Naomi Hirano, Sheng-Yuan Liu, Somnath Dutta, Dipen Sahu, Patricio Sanhueza, Kee-Tae Kim, Mika Juvela, L. Viktor T'oth, Orsolya Feh'er, Jinhua He, J. X. Ge, Siyi Feng, Minho Choi, Miju Kang, Mark A. Thompson, Gary A. Fuller, Di Li, Isabelle Ristorcelli, Ke Wang, James Di Francesco, David Eden, Satoshi Ohashi, Ryo Kandori, Charlotte Vastel, Tomoya Hirota, Takeshi Sakai, Xing Lu, Quang Nguyen Lu'o'ng, Hiroko Shinnaga, Jungha Kim, JCMT Large Program, SCOPE'' collaboration .  Molecular Cloud Cores with High Deuterium Fractions: Nobeyama Mapping Survey .  The Astrophysical Journal Supplement   1 - 45   2021年国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

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  • Nguyen Bich Ngoc, Pham Ngoc Diep, Harriet Parsons, Kate Pattle, Thiem Hoang, Derek Ward-Thompson, Le Ngoc Tram, Charles L. H. Hull, Mehrnoosh Tahani, Ray Furuya, Pierre Bastien, Keping Qiu, Tetsuo Hasegawa, Woojin Kwon, Yasuo Doi, Shih-Ping Lai, Simon Coude, David Berry, Tao-Chung Ching, Jihye Hwang, Archana Soam, Jia-Wei Wang, Doris Arzoumanian, Tyler L. Bourke, Do-Young Byun, Huei-Ru Vivien Chen, Zhiwei Chen, Wen Ping Chen, Mike Chen, Jungyeon Cho, Yunhee Choi, Minho Choi, Antonio Chrysostomou, Eun Jung Chung, Sophia Dai, James Di Francesco, Yan Duan, Hao-Yuan Duan, David Eden, Chakali Eswaraiah, Lapo Fanciullo, Jason Fiege, Laura M. Fissel, Erica Franzmann, Per Friberg, Rachel Friesen, Gary Fuller, Tim Gledhill, Sarah Graves, Jane Greaves, Matt Griffin, Qilao Gu, Ilseung Han, Jennifer Hatchell, Saeko Hayashi, Martin Houde, Tsuyoshi Inoue, Shu-ichiro Inutsuka, Kazunari Iwasaki, Il-Gyo Jeong, Doug Johnstone, Ji-hyun Kang, Sung-ju Kang, Miju Kang, Akimasa Kataoka, Koji Kawabata, Francisca Kemper, Kee-Tae Kim, Jongsoo Kim, Tae-Soo Pyo, Lei Qian, Ramprasad Rao, Mark Rawlings, Jonathan Rawlings, Brendan Retter, John Richer, Andrew Rigby, Sarah Sadavoy, Hiro Saito, Giorgio Savini, Anna Scaife, Masumichi Seta, Gwanjeong Kim, Shinyoung Kim, Kyoung Hee Kim, Mi-Ryang Kim, Florian Kirchschlager, Jason Kirk, Masato I. N. Kobayashi, Patrick M. Koch, Vera Konyves, Takayoshi Kusune, Jungmi Kwon, Kevin Lacaille, Chi-Yan Law, Sang-Sung Lee, Yong-Hee Lee, Chin-Fei Lee, Jeong-Eun Lee, Hyeseung Lee, Chang Won Lee, Di Li, Hua-bai Li, Dalei Li, Hong-Li Liu, Junhao Liu, Tie Liu, Sheng-Yuan Liu, Xing Lu, A-Ran Lyo, Steve Mairs, Masafumi Matsumura, Brenda Matthews, Gerald Moriarty-Schieven, Tetsuya Nagata, Fumitaka Nakamura, Hiroyuki Nakanishi, Nagayoshi Ohashi, Takashi Onaka, Geumsook Park, Nicolas Peretto, Yoshito Shimajiri, Hiroko Shinnaga, Motohide Tamura, Ya-Wen Tang, Xindi Tang, Kohji Tomisaka, Yusuke Tsukamoto, Serena Viti, Hongchi Wang, Anthony Whitworth, Jinjin Xie, Hsi-Wei Yen, Hyunju Yoo, Jinghua Yuan, Hyeong-Sik Yun, Tetsuya Zenko, Yapeng Zhang, Chuan-Peng Zhang, Guoyin Zhang, Jianjun Zhou, Lei Zhu, Ilse de Looze, Philippe Andre, C. Darren Dowell, Stewart Eyres, Sam Falle, Jean-Francois Robitaille, Sven van Loo .  Observations of magnetic fields surrounding LkH$α$ 101 taken by the BISTRO survey with JCMT-POL-2 .      2020年12月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We report the first high spatial resolution measurement of magnetic fields
    surrounding LkH$\alpha$ 101, a part of the Auriga-California molecular cloud.
    The observations were taken with the POL-2 polarimeter on the James Clerk
    Maxwell Telescope within the framework of the B-fields In Star-forming Region
    Observations (BISTRO) survey. Observed polarization of thermal dust emission at
    850 $\mu$m is found to be mostly associated with the red-shifted gas component
    of the cloud. The magnetic field displays a relatively complex morphology. Two
    variants of the Davis-Chandrasekhar-Fermi method, unsharp masking and structure
    function, are used to calculate the strength of magnetic fields in the plane of
    the sky, yielding a similar result of $B_{\rm POS}\sim 115$ $\mathrm{\mu}$G.
    The mass-to-magnetic-flux ratio in critical value units, $\lambda\sim0.3$, is
    the smallest among the values obtained for other regions surveyed by POL-2.
    This implies that the LkH$\alpha$ 101 region is sub-critical and the magnetic
    field is strong enough to prevent gravitational collapse. The inferred $\delta
    B/B_0\sim 0.3$ implies that the large scale component of the magnetic field
    dominates the turbulent one. The variation of the polarization fraction with
    total emission intensity can be fitted by a power-law with an index of
    $\alpha=0.82\pm0.03$, which lies in the range previously reported for molecular
    clouds. We find that the polarization fraction decreases rapidly with proximity
    to the only early B star (LkH$\alpha$ 101) in the region. The magnetic field
    tangling and the joint effect of grain alignment and rotational disruption by
    radiative torques are potential of explaining such a decreasing trend.

    DOI: 10.3847/1538-4357/abd0fc

    arXiv

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    その他リンク: http://arxiv.org/pdf/2012.04297v1

  • Hsi-Wei Yen, Patrick M. Koch, Charles L. H. Hull, Derek Ward-Thompson, Pierre Bastien, Tetsuo Hasegawa, Woojin Kwon, Shih-Ping Lai, Keping Qiu, Tao-Chung Ching, Eun Jung Chung, Simon Coude, James Di Francesco, Pham Ngoc Diep, Yasuo Doi, Chakali Eswaraiah, Sam Falle, Gary Fuller, Ray S. Furuya, Ilseung Han, Jennifer Hatchell, Martin Houde, Shu-ichiro Inutsuka, Doug Johnstone, Ji-hyun Kang, Miju Kang, Kee-Tae Kim, Florian Kirchschlager, Jungmi Kwon, Chang Won Lee, Chin-Fei Lee, Hong-Li Liu, Tie Liu, A-Ran Lyo, Nagayoshi Ohashi, Takashi Onaka, Kate Pattle, Sarah Sadavoy, Hiro Saito, Hiroko Shinnaga, Archana Soam, Mehrnoosh Tahani, Motohide Tamura, Ya-Wen Tang, Xindi Tang, Chuan-Peng Zhang .  The JCMT BISTRO survey: alignment between outflows and magnetic fields in dense cores/clumps .      2020年11月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We compare the directions of molecular outflows of 62 low-mass Class 0 and I
    protostars in nearby (<450 pc) star-forming regions with the mean orientations
    of the magnetic fields on 0.05-0.5 pc scales in the dense cores/clumps where
    they are embedded. The magnetic field orientations were measured using the JCMT
    POL-2 data taken by the BISTRO-1 survey and from the archive. The outflow
    directions were observed with interferometers in the literature. The observed
    distribution of the angles between the outflows and the magnetic fields peaks
    between 15 and 35 degrees. After considering projection effects, our results
    could suggest that the outflows tend to be misaligned with the magnetic fields
    by 50+/-15 degrees in three-dimensional space and are less likely (but not
    ruled out) randomly oriented with respect to the magnetic fields. There is no
    correlation between the misalignment and the bolometric temperatures in our
    sample. In several sources, the small-scale (1000-3000 au) magnetic fields is
    more misaligned with the outflows than their large-scale magnetic fields,
    suggesting that the small-scale magnetic field has been twisted by the
    dynamics. In comparison with turbulent MHD simulations of core formation, our
    observational results are more consistent with models in which the energy
    densities in the magnetic field and the turbulence of the gas are comparable.
    Our results also suggest that the misalignment alone cannot sufficiently reduce
    the efficiency of magnetic braking to enable formation of the observed number
    of large Keplerian disks with sizes larger than 30-50 au.

    DOI: 10.3847/1538-4357/abca99

    arXiv

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    その他リンク: http://arxiv.org/pdf/2011.06731v1

  • Aina Palau, Qizhou Zhang, Josep M. Girart, Junhao Liu, Ram Rao, Patrick M. Koch, Robert Estalella, Huei-Ru Vivien Chen, Hauyu Baobab Liu, Keping Qiu, Zhi-Yun Li, Luis A. Zapata, Sylvain Bontemps, Tao-Chung Ching, Hiroko Shinnaga, Paul T. P. Ho, Aida Ahmadi, Henrik Beuther .  In search for an observational correlation between the fragmentation level and the magnetic field properties of massive dense cores .      2020年10月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Theoretical and numerical works indicate that a strong magnetic field should
    suppress fragmentation in dense cores. However, this has never been tested
    observationally in a relatively large sample of fragmenting massive dense
    cores. Here we use the polarization data obtained in the Submillimeter Array
    Legacy Survey of Zhang et al. (2014) to build a sample of 17 massive dense
    cores where both fragmentation and magnetic field properties are studied in a
    uniform way. We measured the fragmentation level, Nmm, within the field of view
    common to all regions, of ~0.15 pc, with a mass sensitivity of ~0.5 Msun, and a
    spatial resolution of ~1000 AU. In order to obtain the magnetic field strength
    using the Davis-Chandrasekhar-Fermi method, we estimated the dispersion of the
    polarization position angles, the velocity dispersion of the H13CO+(4-3) gas,
    and the density of each core, all averaged within 0.15 pc. The magnetic field
    strength was also inferred using the Angular Dispersion Function method.
    Surprisingly, we found no apparent relation between the fragmentation level and
    the magnetic field strength, while a possible trend of Nmm with the average
    density of the parental core was found. In addition, the average masses of the
    fragments are comparable to the thermal Jeans mass. Therefore, our results
    suggest that thermal fragmentation and gravity dominate the fragmentation
    process in this sample. However, when only cores with similar densities are
    considered, there are hints of a possible anticorrelation between the
    fragmentation level and the magnetic field strength.

    arXiv

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    その他リンク: http://arxiv.org/pdf/2010.12099v1

  • Gwanjeong Kim, Kenichi Tatematsu, Tie Liu, Miss Hee-Weon Yi, Jinhua He, Naomi Hirano, Sheng-Yuan Liu, Minho Choi, Patricio Sanhueza, L. Viktor Toth, Neal J. Evans, Siyi Feng, Mika Juvela, Kee-Tae Kim, Charlotte Vastel, Jeong-Eun Lee, Quang Nguyn-Lu'o'ng, Miju Kang, Isabelle Ristorcelli, O. Fehér, Yuefang Wu, Satoshi Ohashi, Ke Wang, Ryo Kandori, Tomoya Hirota, Takeshi Sakai, Xing Lu, Mark A. Thompson, Gary A. Fuller, Di Li, Hiroko Shinnaga, Jungha Kim .  Molecular Cloud Cores with High Deuterium Fraction: Nobeyama Single-Pointing Survey .      2020年7月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We present the results of a single-pointing survey of 207 dense cores
    embedded in Planck Galactic Cold Clumps distributed in five different
    environments ($\lambda$ Orionis, Orion A, B, Galactic plane, and high
    latitudes) to identify dense cores on the verge of star formation for the study
    of the initial conditions of star formation. We observed these cores in eight
    molecular lines at 76-94 GHz using the Nobeyama 45-m telescope. We find that
    early-type molecules (e.g., CCS) have low detection rates and that late-type
    molecules (e.g., N$_2$H$^+$, c-C$_3$H$_2$) and deuterated molecules (e.g.,
    N$_2$D$^+$, DNC) have high detection rates, suggesting that most of the cores
    are chemically evolved. The deuterium fraction (D/H) is found to decrease with
    increasing distance, indicating that it suffers from differential beam dilution
    between the D/H pair of lines for distant cores ($>$1 kpc). For $\lambda$
    Orionis, Orion A, and B located at similar distances, D/H is not significantly
    different, suggesting that there is no systematic difference in the observed
    chemical properties among these three regions. We identify at least eight high
    D/H cores in the Orion region and two at high latitudes, which are most likely
    to be close to the onset of star formation. There is no clear evidence of the
    evolutionary change in turbulence during the starless phase, suggesting that
    the dissipation of turbulence is not a major mechanism for the beginning of
    star formation as judged from observations with a beam size of 0.04 pc.

    DOI: 10.3847/1538-4365/aba746

    arXiv

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    その他リンク: http://arxiv.org/pdf/2007.12319v1

  • Yasuo Doi, Tetsuo Hasegawa, Ray S. Furuya, Simon Coudé, Charles L. H. Hull, Doris Arzoumanian, Pierre Bastien, Michael Chun-Yuan Chen, James di Francesco, Rachel Friesen, Martin Houde, Shu-ichiro Inutsuka, Steve Mairs, Masafumi Matsumura, Takashi Onaka, Sarah Sadavoy, Yoshito Shimajiri, Mehrnoosh Tahani, Kohji Tomisaka, Chakali Eswaraiah, Patrick M. Koch, Kate Pattle, Chang Won Lee, Motohide Tamura, David Berry, Tao-Chung Ching, Jihye Hwang, Woojin Kwon, Archana Soam, Jia-Wei Wang, Shih-Ping Lai, Keping Qiu, Derek Ward-Thompson, Do-Young Byun, Huei-Ru V. Chen, Wen Ping Chen, Zhiwei Chen, Jungyeon Cho, Minho Choi, Yunhee Choi, Antonio Chrysostomou, Eun Jung Chung, Pham Ngoc Diep, Hao-Yuan Duan, Lapo Fanciullo, Jason Fiege, Erica Franzmann, Per Friberg, Gary Fuller, Tim Gledhill, Sarah F. Graves, Jane S. Greaves, Matt J. Griffin, Qilao Gu, Ilseung Han, Jennifer Hatchell, Saeko S. Hayashi, Thiem Hoang, Tsuyoshi Inoue, Kazunari Iwasaki, Il-Gyo Jeong, Doug Johnstone, Yoshihiro Kanamori, Ji-hyun Kang, Miju Kang, Sung-Ju Kang, Akimasa Kataoka, Koji S. Kawabata, Francisca Kemper, Gwanjeong Kim, Jongsoo Kim, Kee-Tae Kim, Kyoung Hee Kim, Mi-Ryang Kim, Shinyoung Kim, Jason M. Kirk, Masato I. N. Kobayashi, Vera Konyves, Takayoshi Kusune, Jungmi Kwon, Kevin Lacaille, Chi-Yan Law, Chin-Fei Lee, Hyeseung Lee, Jeong-Eun Lee, Sang-Sung Lee, Yong-Hee Lee, Dalei Li, Di Li, Hua-Bai Li, Hong-Li Liu, Junhao Liu, Sheng-Yuan Liu, Tie Liu, Ilse de Looze, A-Ran Lyo, Brenda C. Matthews, Gerald H. Moriarty-Schieven, Tetsuya Nagata, Fumitaka Nakamura, Hiroyuki Nakanishi, Nagayoshi Ohashi, Geumsook Park, Harriet Parsons, Nicolas Peretto, Tae-Soo Pyo, Lei Qian, Ramprasad Rao, Mark G. Rawlings, Brendan Retter, John Richer, Andrew Rigby, Hiro Saito, Giorgio Savini, Anna M. M. Scaife, Masumichi Seta, Hiroko Shinnaga, Ya-Wen Tang, Yusuke Tsukamoto, Serena Viti, Hongchi Wang, Anthony P. Whitworth, Hsi-Wei Yen, Hyunju Yoo, Jinghua Yuan, Hyeong-Sik Yun, Tetsuya Zenko, Chuan-Peng Zhang, Guoyin Zhang, Yapeng Zhang, Jianjun Zhou, Lei Zhu, Philippe André, C. Darren Dowell, Stewart P. S. Eyres, Sam Falle, Sven van Loo, Jean-François Robitaille .  The JCMT BISTRO Survey: Magnetic Fields Associated with a Network of Filaments in NGC 1333 .      2020年7月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We present new observations of the active star-formation region NGC 1333 in
    the Perseus molecular cloud complex from the James Clerk Maxwell Telescope
    B-Fields In Star-forming Region Observations (BISTRO) survey with the POL-2
    instrument. The BISTRO data cover the entire NGC 1333 complex (~1.5 pc x 2 pc)
    at 0.02 pc resolution and spatially resolve the polarized emission from
    individual filamentary structures for the first time. The inferred magnetic
    field structure is complex as a whole, with each individual filament aligned at
    different position angles relative to the local field orientation. We combine
    the BISTRO data with low- and high- resolution data derived from Planck and
    interferometers to study the multiscale magnetic field structure in this
    region. The magnetic field morphology drastically changes below a scale of ~1
    pc and remains continuous from the scales of filaments (~0.1 pc) to that of
    protostellar envelopes (~0.005 pc or ~1000 au). Finally, we construct simple
    models in which we assume that the magnetic field is always perpendicular to
    the long axis of the filaments. We demonstrate that the observed variation of
    the relative orientation between the filament axes and the magnetic field
    angles are well reproduced by this model, taking into account the projection
    effects of the magnetic field and filaments relative to the plane of the sky.
    These projection effects may explain the apparent complexity of the magnetic
    field structure observed at the resolution of BISTRO data toward the filament
    network.

    DOI: 10.3847/1538-4357/aba1e2

    arXiv

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    その他リンク: http://arxiv.org/pdf/2007.00176v2

  • Peter Scicluna, Hiroko Shinnaga, Jonathan Marshall, Jan Wouterloot, Iain McDonald, Steven Goldman, Sofia Wallström, Jacco Th. van Loon, Thavisha Dharmawardena, Lapo Fanciullo, Sundar Srinivasan .  Studies of Evolved Stars in the Next Decade: EAO Submillimetre Futures White Paper Series, 2019 .      2020年2月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    This white paper discusses recent progress in the field of evolved stars,
    primarily highlighting the contributions of the James Clerk Maxwell Telescope.
    It discusses the ongoing project, the \emph{Nearby Evolved Stars Survey}
    (NESS), and the potential to build upon NESS in the next decade. It then
    outlines a number of science cases which may become feasible with the proposed
    850\,$\mu$m camera which is due to become available at the JCMT in late 2022.
    These include mapping the extended envelopes of evolved stars, including in
    polarisation, and time-domain monitoring of their variations. The improved
    sensitivity of the proposed instrument will facilitate statistical studies that
    put the morphology, polarisation properties and sub-mm variability in
    perspective with a relatively modest commitment of time that would be
    impossible with current instrumentation. We also consider the role that could
    be played by other continuum wavelengths, heterodyne instruments or other
    facilities in contributing towards these objectives.

    arXiv

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    その他リンク: http://arxiv.org/pdf/2002.03100v1

  • Thavisha E. Dharmawardena, Francisca Kemper, Sundar Srinivasan, Peter Scicluna, Jonathan P. Marshall, Jan G. A. Wouterloot, Jane Greaves, Steven R. Goldman, Jacco Th. van Loon, Mikako Matsuura, Iain McDonald, Jinhua He, Albert A. Zijlstra, Jesús A. Toalá, Sofia H. J. Wallström, Hyosun Kim, Alfonso Trejo, Paolo Ventura, Eric Lagadec, Martha L. Boyer, Tie Liu, Gioia Rau, Hideyuki Izumiura, Jan Cami, Wayne Holland, Olivia Jones, Hiroko Shinnaga .  The Nearby Evolved Stars Survey: I. JCMT/SCUBA-2 Sub-millimetre detection of the detached shell of U Antliae .      2019年8月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We present the highest resolution single-dish submillimetre observations of
    the detached shell source U Antliae to date. The observations were obtained at
    $450~\micron$ and $850~\micron$ with SCUBA-2 instrument on the James Clerk
    Maxwell Telescope as part of the Nearby Evolved Stars Survey. The emission at
    $850~\micron$ peaks at $40\arcsec$ with hints of a second peak seen at $\sim
    20\arcsec$. The emission can be traced out to a radius of $56\arcsec$ at a
    $3\sigma$ level. The outer peak observed at $850~\micron$ aligns well with the
    peak observed at Herschel/PACS wavelengths. With the help of spectral energy
    distribution fitting and radiative transfer calculations of multiple-shell
    models for the circumstellar envelope, we explore the various shell structures
    and the variation of grain sizes along the in the circumstellar envelope. We
    determine a total shell dust mass of $(2.0 \pm 0.3) \times 10^{-5}$ M$_{\odot}$
    and established that the thermal pulse which gave rise to the detached shell
    occurred 3500 $\pm$ 500 years ago.

    DOI: 10.1093/mnras/stz2334

    arXiv

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    その他リンク: http://arxiv.org/pdf/1908.04575v1

  • Simon Coudé, Pierre Bastien, Martin Houde, Sarah Sadavoy, Rachel Friesen, James Di Francesco, Doug Johnstone, Steve Mairs, Tetsuo Hasegawa, Woojin Kwon, Shih-Ping Lai, Keping Qiu, Derek Ward-Thompson, David Berry, Michael Chun-Yuan Chen, Jason Fiege, Erica Franzmann, Jennifer Hatchell, Kevin Lacaille, Brenda C. Matthews, Gerald H. Moriarty-Schieven, Andy Pon, Philippe André, Doris Arzoumanian, Yusuke Aso, Do-Young Byun, Eswaraiah Chakali, Huei-Ru Chen, Wen Ping Chen, Tao-Chung Ching, Jungyeon Cho, Minho Choi, Antonio Chrysostomou, Eun Jung Chung, Yasuo Doi, Emily Drabek-Maunder, C. Darren Dowell, Stewart P. S. Eyres, Sam Falle, Per Friberg, Gary Fuller, Ray S. Furuya, Tim Gledhill, Sarah F. Graves, Jane S. Greaves, Matt J. Griffin, Qilao Gu, Saeko S. Hayashi, Thiem Hoang, Wayne Holland, Tsuyoshi Inoue, Shu-ichiro Inutsuka, Kazunari Iwasaki, Il-Gyo Jeong, Yoshihiro Kanamori, Akimasa Kataoka, Ji-hyun Kang, Miju Kang, Sung-ju Kang, Koji S. Kawabata, Francisca Kemper, Gwanjeong Kim, Jongsoo Kim, Kee-Tae Kim, Kyoung Hee Kim, Mi-Ryang Kim, Shinyoung Kim, Jason M. Kirk, Masato I. N. Kobayashi, Patrick M. Koch, Jungmi Kwon, Jeong-Eun Lee, Chang Won Lee, Sang-Sung Lee, Dalei Li, Di Li, Hua-bai Li, Hong-Li Liu, Junhao Liu, Sheng-Yuan Liu, Tie Liu, Sven van Loo, A-Ran Lyo, Masafumi Matsumura, Tetsuya Nagata, Fumitaka Nakamura, Hiroyuki Nakanishi, Nagayoshi Ohashi, Takashi Onaka, Harriet Parsons, Kate Pattle, Nicolas Peretto, Tae-Soo Pyo, Lei Qian, Ramprasad Rao, Mark G. Rawlings, Brendan Retter, John Richer, Andrew Rigby, Jean-François Robitaille, Hiro Saito, Giorgio Savini, Anna M. M. Scaife, Masumichi Seta, Hiroko Shinnaga, Archana Soam, Motohide Tamura, Ya-Wen Tang, Kohji Tomisaka, Yusuke Tsukamoto, Hongchi Wang, Jia-Wei Wang, Anthony P. Whitworth, Hsi-Wei Yen, Hyunju Yoo, Jinghua Yuan, Tetsuya Zenko, Chuan-Peng Zhang, Guoyin Zhang, Jianjun Zhou, Lei Zhu .  The JCMT BISTRO Survey: The Magnetic Field of the Barnard 1 Star-Forming Region .      2019年4月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We present the POL-2 850 $\mu$m linear polarization map of the Barnard 1
    clump in the Perseus molecular cloud complex from the B-fields In STar-forming
    Region Observations (BISTRO) survey at the James Clerk Maxwell Telescope. We
    find a trend of decreasing polarization fraction as a function of total
    intensity, which we link to depolarization effects towards higher density
    regions of the cloud. We then use the polarization data at 850 $\mu$m to infer
    the plane-of-sky orientation of the large-scale magnetic field in Barnard 1.
    This magnetic field runs North-South across most of the cloud, with the
    exception of B1-c where it turns more East-West. From the dispersion of
    polarization angles, we calculate a turbulence correlation length of $5.0 \pm
    2.5$ arcsec ($1500$ au), and a turbulent-to-total magnetic energy ratio of $0.5
    \pm 0.3$ inside the cloud. We combine this turbulent-to-total magnetic energy
    ratio with observations of NH$_3$ molecular lines from the Green Bank Ammonia
    Survey (GAS) to estimate the strength of the plane-of-sky component of the
    magnetic field through the Davis-Chandrasekhar-Fermi method. With a
    plane-of-sky amplitude of $120 \pm 60$ $\mu$G and a criticality criterion
    $\lambda_c = 3.0 \pm 1.5$, we find that Barnard 1 is a supercritical molecular
    cloud with a magnetic field nearly dominated by its turbulent component.

    DOI: 10.3847/1538-4357/ab1b23

    arXiv

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    その他リンク: http://arxiv.org/pdf/1904.07221v2

  • Junhao Liu, Keping Qiu, David Berry, James Di Francesco, Pierre Bastien, Patrick M. Koch, Ray S. Furuya, Kee-Tae Kim, Simon Coudé, Chang Won Lee, Archana Soam, Chakali Eswaraiah, Di Li, Jihye Hwang, A-Ran Lyo, Kate Pattle, Tetsuo Hasegawa, Woojin Kwon, Shih-Ping Lai, Derek Ward-Thompson, Tao-Chung Ching, Zhiwei Chen, Qilao Gu, Dalei Li, Hua-bai Li, Hong-Li Liu, Lei Qian, Hongchi Wang, Jinghua Yuan, Chuan-Peng Zhang, Guoyin Zhang, Ya-Peng Zhang, Jianjun Zhou, Lei Zhu, Philippe André, Doris Arzoumanian, Yusuke Aso, Do-Young Byun, Michael Chun-Yuan Chen, Huei-Ru Vivien Chen, Wen Ping Chen, Jungyeon Cho, Minho Choi, Antonio Chrysostomou, Eun Jung Chung, Yasuo Doi, Emily Drabek-Maunder, C. Darren Dowell, Stewart P. S. Eyres, Sam Falle, Lapo Fanciullo, Jason Fiege, Erica Franzmann, Per Friberg, Rachel K. Friesen, Gary Fuller, Tim Gledhill, Sarah F. Graves, Jane S. Greaves, Matt J. Griffin, Ilseung Han, Jennifer Hatchell, Saeko S. Hayashi, Thiem Hoang, Wayne Holland, Martin Houde, Tsuyoshi Inoue, Shu-ichiro Inutsuka, Kazunari Iwasaki, Il-Gyo Jeong, Doug Johnstone, Yoshihiro Kanamori, Ji-hyun Kang, Miju Kang, Sung-ju Kang, Akimasa Kataoka, Koji S. Kawabata, Francisca Kemper, Gwanjeong Kim, Jongsoo Kim, Kyoung Hee Kim, Mi-Ryang Kim, Shinyoung Kim, Jason M. Kirk, Masato I. N. Kobayashi, Takayoshi Kusune, Jungmi Kwon, Kevin M. Lacaille, Chin-Fei Lee, Jeong-Eun Lee, Hyeseung Lee, Sang-Sung Lee, Sheng-Yuan Liu, Tie Liu, Sven van Loo, Steve Mairs, Masafumi Matsumura, Brenda C. Matthews, Gerald H. Moriarty-Schieven, Tetsuya Nagata, Fumitaka Nakamura, Hiroyuki Nakanishi, Nagayoshi Ohashi, Takashi Onaka, Josh Parker, Harriet Parsons, Enzo Pascale, Nicolas Peretto, Andy Pon, Tae-Soo Pyo, Ramprasad Rao, Mark G. Rawlings, Brendan Retter, John Richer, Andrew Rigby, Jean-François Robitaille, Sarah Sadavoy, Hiro Saito, Giorgio Savini, Anna M. M. Scaife, Masumichi Seta, Hiroko Shinnaga, Motohide Tamura, Ya-Wen Tang, Kohji Tomisaka, Yusuke Tsukamoto, Jia-Wei Wang, Anthony P. Whitworth, Hsi-Wei Yen, Hyunju Yoo, Tetsuya Zenko .  The JCMT BISTRO Survey: The Magnetic Field In The Starless Core $ρ$ Ophiuchus C .      2019年2月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We report 850~$\mu$m dust polarization observations of a low-mass ($\sim$12
    $M_{\odot}$) starless core in the $\rho$ Ophiuchus cloud, Ophiuchus C, made
    with the POL-2 instrument on the James Clerk Maxwell Telescope (JCMT) as part
    of the JCMT B-fields In STar-forming Region Observations (BISTRO) survey. We
    detect an ordered magnetic field projected on the plane of sky in the starless
    core. The magnetic field across the $\sim$0.1~pc core shows a predominant
    northeast-southwest orientation centering between $\sim$40$^\circ$ to
    $\sim$100$^\circ$, indicating that the field in the core is well aligned with
    the magnetic field in lower-density regions of the cloud probed by
    near-infrared observations and also the cloud-scale magnetic field traced by
    Planck observations. The polarization percentage ($P$) decreases with an
    increasing total intensity ($I$) with a power-law index of $-$1.03 $\pm$ 0.05.
    We estimate the plane-of-sky field strength ($B_{\mathrm{pos } }$) using modified
    Davis-Chandrasekhar-Fermi (DCF) methods based on structure function (SF),
    auto-correlation (ACF), and unsharp masking (UM) analyses. We find that the
    estimates from the SF, ACF, and UM methods yield strengths of 103 $\pm$ 46
    $\mu$G, 136 $\pm$ 69 $\mu$G, and 213 $\pm$ 115 $\mu$G, respectively. Our
    calculations suggest that the Ophiuchus C core is near magnetically critical or
    slightly magnetically supercritical (i.e. unstable to collapse). The total
    magnetic energy calculated from the SF method is comparable to the turbulent
    energy in Ophiuchus C, while the ACF method and the UM method only set upper
    limits for the total magnetic energy because of large uncertainties.

    DOI: 10.3847/1538-4357/ab0958

    arXiv

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    その他リンク: http://arxiv.org/pdf/1902.07734v1

  • Ray S. Furuya, Yoshimi Kitamura, Hiroko Shinnaga .  A 1000 AU Scale Molecular Outflow Driven by a Protostar with an age of <4000 Years .      2018年12月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    To shed light on the early phase of a low-mass protostar formation process,
    we conducted interferometric observations towards a protostar GF9-2 using the
    CARMA and SMA. The observations have been carried out in the CO J=3-2 line and
    in the continuum emission at the wavelengths of 3 mm, 1 mm and 850 micron. All
    the continuum images detected a single point-like source with a radius of
    250+/-80 AU at the center of the previously known ~3 Msun molecular cloud core.
    A compact emission is detected towards the object at the Spitzer MIPS and IRAC
    bands as well as the four bands at the WISE. Our spectroscopic imaging of the
    CO line revealed that the continuum source is driving a 1000 AU scale molecular
    outflow, including a pair of lobes where a collimated "higher" velocity red
    lobe exists inside a poorly collimated "lower" velocity red lobe. These lobes
    are rather young and the least powerful ones so far detected. A protostellar
    mass of M~<0.06 Msun was estimated using an upper limit of the protostellar age
    of (4+/-1)x10^3 yrs and an inferred non-spherical steady mass accretion rate of
    ~10^{-5} Msun/yr. Together with results from an SED analysis, we discuss that
    the outflow system is driven by a protostar whose surface temperature
    of~3,000K, and that the natal cloud core is being dispersed by the outflow.

    arXiv

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    その他リンク: http://arxiv.org/pdf/1812.07806v1

  • Jia-Wei Wang, Shih-Ping Lai, Chakali Eswaraiah, Kate Pattle, James Di Francesco, Doug Johnstone, Patrick M. Koch, Tie Liu, Motohide Tamura, Ray S. Furuya, Takashi Onaka, Derek Ward-Thompson, Archana Soam, Kee-Tae Kim, Chang Won Lee, Chin-Fei Lee, Steve Mairs, Doris Arzoumanian, Gwanjeong Kim, Thiem Hoang, Jihye Hwang, Sheng-Yuan Liu, David Berry, Pierre Bastien, Tetsuo Hasegawa, Woojin Kwon, Keping Qiu, Philippe André, Yusuke Aso, Do-Young Byun, Huei-Ru Chen, Michael C. Chen, Wen Ping Chen, Tao-Chung Ching, Jungyeon Cho, Minho Choi, Antonio Chrysostomou, Eun Jung Chung, Simon Coudé, Yasuo Doi, C. Darren Dowell, Emily Drabek-Maunder, Hao-Yuan Duan, Stewart P. S. Eyres, Sam Falle, Lapo Fanciullo, Jason Fiege, Erica Franzmann, Per Friberg, Rachel K. Friesen, Gary Fuller, Tim Gledhill, Sarah F. Graves, Jane S. Greaves, Matt J. Griffin, Qilao Gu, Ilseung Han, Jennifer Hatchell, Saeko S. Hayashi, Wayne Holland, Martin Houde, Tsuyoshi Inoue, Shu-ichiro Inutsuka, Kazunari Iwasaki, Il-Gyo Jeong, Yoshihiro Kanamori, Ji-hyun Kang, Miju Kang, Sung-ju Kang, Akimasa Kataoka, Koji S. Kawabata, Francisca Kemper, Jongsoo Kim, Kyoung Hee Kim, Mi-Ryang Kim, Shinyoung Kim, Jason M. Kirk, Masato I. N. Kobayashi, Vera Konyves, Jungmi Kwon, Kevin M. Lacaille, Hyeseung Lee, Jeong-Eun Lee, Sang-Sung Lee, Yong-Hee Lee, Dalei Li, Di Li, Hua-bai Li, Hong-Li Liu, Junhao Liu, A-Ran Lyo, Masafumi Matsumura, Brenda C. Matthews, Gerald H. Moriarty-Schieven, Tetsuya Nagata, Fumitaka Nakamura, Hiroyuki Nakanishi, Nagayoshi Ohashi, Geumsook Park, Harriet Parsons, Enzo Pascale, Nicolas Peretto, Andy Pon, Tae-Soo Pyo, Lei Qian, Ramprasad Rao, Mark G. Rawlings, Brendan Retter, John Richer, Andrew Rigby, Jean-François Robitaille, Sarah Sadavoy, Hiro Saito, Giorgio Savini, Anna M. M. Scaife, Masumichi Seta, Hiroko Shinnaga, Ya-Wen Tang, Kohji Tomisaka, Yusuke Tsukamoto, Sven van Loo, Hongchi Wang, Anthony P. Whitworth, Hsi-Wei Yen, Hyunju Yoo, Jinghua Yuan, Hyeong-Sik Yun, Tetsuya Zenko, Chuan-Peng Zhang, Guoyin Zhang, Ya-Peng Zhang, Jianjun Zhou, Zhu .  JCMT BISTRO survey: Magnetic Fields within the Hub-Filament Structure in IC 5146 .      2018年12月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We present the 850 $\mu$m polarization observations toward the IC5146
    filamentary cloud taken using the Submillimetre Common-User Bolometer Array 2
    (SCUBA-2) and its associated polarimeter (POL-2), mounted on the James Clerk
    Maxwell Telescope (JCMT), as part of the B-fields In STar forming Regions
    Observations (BISTRO). This work is aimed at revealing the magnetic field
    morphology within a core-scale ($\lesssim 1.0$ pc) hub-filament structure (HFS)
    located at the end of a parsec-scale filament. To investigate whether or not
    the observed polarization traces the magnetic field in the HFS, we analyze the
    dependence between the observed polarization fraction and total intensity using
    a Bayesian approach with the polarization fraction described by the Rice
    likelihood function, which can correctly describe the probability density
    function (PDF) of the observed polarization fraction for low signal-to-noise
    ratio (SNR) data. We find a power-law dependence between the polarization
    fraction and total intensity with an index of 0.56 in $A_V\sim$ 20--300 mag
    regions, suggesting that the dust grains in these dense regions can still be
    aligned with magnetic fields in the IC5146 regions. Our polarization maps
    reveal a curved magnetic field, possibly dragged by the contraction along the
    parsec-scale filament. We further obtain a magnetic field strength of
    0.5$\pm$0.2 mG toward the central hub using the Davis-Chandrasekhar-Fermi
    method, corresponding to a mass-to-flux criticality of $\sim$ $1.3\pm0.4$ and
    an Alfv\'{e}nic Mach number of $<$0.6. These results suggest that gravity and
    magnetic field is currently of comparable importance in the HFS, and turbulence
    is less important.

    DOI: 10.3847/1538-4357/ab13a2

    arXiv

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    その他リンク: http://arxiv.org/pdf/1812.05818v3

  • Archana Soam, Kate Pattle, Derek Ward-Thompson, Chang Won Lee, Sarah Sadavoy, Patrick M. Koch, Gwanjeong Kim, Jungmi Kwon, Woojin Kwon, Doris Arzoumanian, David Berry, Thiem Hoang, Motohide Tamura, Sang-Sung Lee, Tie Liu, Kee-Tae Kim, Doug Johnstone, Fumitaka Nakamura, A-Ran Lyo, Takashi Onaka, Jongsoo Kim, Ray S. Furuya, Tetsuo Hasegawa, Shih-Ping Lai, Pierre Bastien, Eun Jung Chung, Shinyoung Kim, Harriet Parsons, Mark Rawlings, Steve Mairs, Sarah F. Graves, J. -F. Robitaille, Hong-Li Liu, Anthony P. Whitworth, Chakali Eswaraiah, Ramprasad Rao, Hyunju Yoo, Martin Houde, Ji-hyun Kang, Yasuo Doi, Minho Choi, Miju Kang, Simon Coude, Hua-bai Li, Masafumi Matsumura, Brenda C. Matthews, Andy Pon, James Di Francesco, Saeko S. Hayashi, Koji S. Kawabata, Shu-ichiro Inutsuka, Keping Qiu, Erica Franzmann, Per Friberg, Jane S. Greaves, Jason M. Kirk, Di Li, Hiroko Shinnaga, Sven van Loo, Yusuke Aso, Do-Young Byun, Huei-Ru Chen, Mike C. -Y. Chen, Wen Ping Chen, Tao-Chung Ching, Jungyeon Cho, Antonio Chrysostomou, Emily Drabek-Maunder, Stewart P. S. Eyres, Jason Fiege, Rachel K. Friesen, Gary Fuller, Tim Gledhill, Matt J. Griffin, Qilao Gu, Jennifer Hatchell, Wayne Holland, Tsuyoshi Inoue, Kazunari Iwasaki, Il-Gyo Jeong, Sung-ju Kang, Francisca Kemper, Kyoung Hee Kim, Mi-Ryang Kim, Kevin M. Lacaille, Jeong-Eun Lee, Dalei Li, Junhao Liu, Sheng-Yuan Liu, Gerald H. Moriarty-Schieven, Hiroyuki Nakanishi, Nagayoshi Ohashi, Nicolas Peretto, Tae-Soo Pyo, Lei Qian, Brendan Retter, John Richer, Andrew Rigby, Giorgio Savini, Anna M. M. Scaife, Ya-Wen Tang, Kohji Tomisaka, Hongchi Wang, Jia-Wei Wang, Hsi-Wei Yen, Jinghua Yuan, Chuan-Peng Zhang, Guoyin Zhang, Jianjun Zhou, Lei Zhu, Philippe Andre, C. Darren Dowell, Sam Falle, Yusuke Tsukamoto, Yoshihiro Kanamori, Akimasa Kataoka, Masato I. N. Kobayashi, Tetsuya Nagata, Hiro Saito, Masumichi Seta, Jihye Hwang, Ilseung Han, Hyeseung Lee, Tetsuya Zenko .  Magnetic fields towards Ophiuchus-B derived from SCUBA-2 polarization measurements .      2018年5月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We present the results of dust emission polarization measurements of
    Ophiuchus-B (Oph-B) carried out using the Submillimetre Common-User Bolometer
    Array 2 (SCUBA-2) camera with its associated polarimeter (POL-2) on the James
    Clerk Maxwell Telescope (JCMT) in Hawaii. This work is part of the B-fields In
    Star-forming Region Observations (BISTRO) survey initiated to understand the
    role of magnetic fields in star formation for nearby star-forming molecular
    clouds. We present a first look at the geometry and strength of magnetic fields
    in Oph-B. The field geometry is traced over $\sim$0.2 pc, with clear detection
    of both of the sub-clumps of Oph-B. The field pattern appears significantly
    disordered in sub-clump Oph-B1. The field geometry in Oph-B2 is more ordered,
    with a tendency to be along the major axis of the clump, parallel to the
    filamentary structure within which it lies. The degree of polarization
    decreases systematically towards the dense core material in the two sub-clumps.
    The field lines in the lower density material along the periphery are smoothly
    joined to the large scale magnetic fields probed by NIR polarization
    observations. We estimated a magnetic field strength of 630$\pm$410 $\mu$G in
    the Oph-B2 sub-clump using a Davis-Chandeasekhar-Fermi analysis. With this
    magnetic field strength, we find a mass-to-flux ratio $\lambda$= 1.6$\pm$1.1,
    which suggests that the Oph-B2 clump is slightly magnetically supercritical.

    DOI: 10.3847/1538-4357/aac4a6

    arXiv

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    その他リンク: http://arxiv.org/pdf/1805.06131v2

  • Jungmi Kwon, Yasuo Doi, Motohide Tamura, Masafumi Matsumura, Kate Pattle, David Berry, Sarah Sadavoy, Brenda C. Matthews, Derek Ward-Thompson, Tetsuo Hasegawa, Ray S. Furuya, Andy Pon, James Di Francesco, Doris Arzoumanian, Saeko S. Hayashi, Koji S. Kawabata, Takashi Onaka, Minho Choi, Miju Kang, Thiem Hoang, Chang Won Lee, Sang-Sung Lee, Hong-Li Liu, Tie Liu, Shu-Ichiro Inutsuka, Chakali Eswaraiah, Pierre Bastien, Woojin Kwon, Shih-Ping Lai, Keping Qiu, Simon Coude, Erica Franzmann, Per Friberg, Sarah F. Graves, Jane S. Greaves, Martin Houde, Doug Johnstone, Jason M. Kirk, Patrick M. Koch, Di Li, Harriet Parsons, Ramprasad Rao, Mark Rawlings, Hiroko Shinnaga, Sven Van Loo, Yusuke Aso, Do-Young Byun, Huei-Ru Chen, Mike C. -Y. Chen, Wen Ping Chen, Tao-Chung Ching, Jungyeon Cho, Antonio Chrysostomou, Eun Jung Chung, Emily Drabek-Maunder, Stewart P. S. Eyres, Jason Fiege, Rachel K. Friesen, Gary Fuller, Tim Gledhill, Matt J. Griffin, Qilao Gu, Jennifer Hatchell, Wayne Holland, Tsuyoshi Inoue, Kazunari Iwasaki, Il-Gyo Jeong, Ji-Hyun Kang, Sung-Ju Kang, Francisca Kemper, Gwanjeong Kim, Jongsoo Kim, Kee-Tae Kim, Kyoung Hee Kim, Mi-Ryang Kim, Shinyoung Kim, Kevin M. Lacaille, Jeong-Eun Lee, Dalei Li, Hua-Bai Li, Junhao Liu, Sheng-Yuan Liu, A-Ran Lyo, Steve Mairs, Gerald H. Moriarty-Schieven, Fumitaka Nakamura, Hiroyuki Nakanishi, Nagayoshi Ohashi, Nicolas Peretto, Tae-Soo Pyo, Lei Qian, Brendan Retter, John Richer, Andrew Rigby, Jean-Franois Robitaille, Giorgio Savini, Anna M. M. Scaife, Archana Soam, Ya-Wen Tang, Kohji Tomisaka, Hongchi Wang, Jia-Wei Wang, Anthony P. Whitworth, Hsi-Wei Yen, Hyunju Yoo, Jinghua Yuan, Chuan-Peng Zhang, Guoyin Zhang, Jianjun Zhou, Lei Zhu, Philippe Andre, C. Darren Dowell, Sam Falle, Yusuke Tsukamoto, Takao Nakagawa, Yoshihiro Kanamori, Akimasa Kataoka, Masato I. N. Kobayashi, Tetsuya Nagata, Hiro Saito, Masumichi Seta, Tetsuya Zenko .  A First Look at BISTRO Observations of The $ρ$ Oph-A core .      2018年4月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We present 850 $\mu$m imaging polarimetry data of the $\rho$ Oph-A core taken
    with the Submillimeter Common-User Bolometer Array-2 (SCUBA-2) and its
    polarimeter (POL-2), as part of our ongoing survey project, BISTRO (B-fields In
    STar forming RegiOns). The polarization vectors are used to identify the
    orientation of the magnetic field projected on the plane of the sky at a
    resolution of 0.01 pc. We identify 10 subregions with distinct polarization
    fractions and angles in the 0.2 pc $\rho$ Oph A core; some of them can be part
    of a coherent magnetic field structure in the $\rho$ Oph region. The results
    are consistent with previous observations of the brightest regions of $\rho$
    Oph-A, where the degrees of polarization are at a level of a few percents, but
    our data reveal for the first time the magnetic field structures in the fainter
    regions surrounding the core where the degree of polarization is much higher
    ($> 5 \%$). A comparison with previous near-infrared polarimetric data shows
    that there are several magnetic field components which are consistent at
    near-infrared and submillimeter wavelengths. Using the
    Davis-Chandrasekhar-Fermi method, we also derive magnetic field strengths in
    several sub-core regions, which range from approximately 0.2 to 5 mG. We also
    find a correlation between the magnetic field orientations projected on the sky
    with the core centroid velocity components.

    DOI: 10.3847/1538-4357/aabd82

    arXiv

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    その他リンク: http://arxiv.org/pdf/1804.09313v1

  • Nico Krieger, Jürgen Ott, Henrik Beuther, Fabian Walter, J. M. Diederik Kruijssen, David S. Meier, Elisabeth A. C. Mills, Yanett Contreras, Phil Edwards, Adam Ginsburg, Christian Henkel, Jonathan Henshaw, James Jackson, Jens Kauffmann, Steven Longmore, Sergio Martin, Mark R. Morris, Thushara Pillai, Matthew Rickert, Erik Rosolowsky, Hiroko Shinnaga, Andrew Walsh, Farhad Yusef-Zadeh, Qizhou Zhang .  The Survey of Water and Ammonia in the Galactic Center (SWAG): Molecular Cloud Evolution in the Central Molecular Zone .      2017年10月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The Survey of Water and Ammonia in the Galactic Center (SWAG) covers the
    Central Molecular Zone (CMZ) of the Milky Way at frequencies between 21.2 and
    25.4 GHz obtained at the Australia Telescope Compact Array at $\sim 0.9$ pc
    spatial and $\sim 2.0$ km s$^{-1}$ spectral resolution. In this paper, we
    present data on the inner $\sim 250$ pc ($1.4^\circ$) between Sgr C and Sgr B2.
    We focus on the hyperfine structure of the metastable ammonia inversion lines
    (J,K) = (1,1) - (6,6) to derive column density, kinematics, opacity and kinetic
    gas temperature. In the CMZ molecular clouds, we find typical line widths of
    $8-16$ km s$^{-1}$ and extended regions of optically thick ($\tau > 1$)
    emission. Two components in kinetic temperature are detected at $25-50$ K and
    $60-100$ K, both being significantly hotter than dust temperatures throughout
    the CMZ. We discuss the physical state of the CMZ gas as traced by ammonia in
    the context of the orbital model by Kruijssen et al. (2015) that interprets the
    observed distribution as a stream of molecular clouds following an open
    eccentric orbit. This allows us to statistically investigate the time
    dependencies of gas temperature, column density and line width. We find heating
    rates between $\sim 50$ and $\sim 100$ K Myr$^{-1}$ along the stream orbit. No
    strong signs of time dependence are found for column density or line width.
    These quantities are likely dominated by cloud-to-cloud variations. Our results
    qualitatively match the predictions of the current model of tidal triggering of
    cloud collapse, orbital kinematics and the observation of an evolutionary
    sequence of increasing star formation activity with orbital phase.

    DOI: 10.3847/1538-4357/aa951c

    arXiv

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    その他リンク: http://arxiv.org/pdf/1710.06902v1

  • Tomofumi Umemoto, Tetsuhiro Minamidani, Nario Kuno, Shinji Fujita, Mitsuhiro Matsuo, Atsushi Nishimura, Kazufumi Torii, Tomoka Tosaki, Mikito Kohno, Mika Kuriki, Yuya Tsuda, Akihiko Hirota, Satoshi Ohashi, Mitsuyoshi Yamagishi, Toshihiro Handa, Hiroyuki Nakanishi, Toshihiro Omodaka, Nagito Koide, Naoko Matsumoto, Toshikazu Onishi, Kazuki Tokuda, Masumichi Seta, Yukinori Kobayashi, Kengo Tachihara, Hidetoshi Sano, Yusuke Hattori, Sachiko Onodera, Yumiko Oasa, Kazuhisa Kamegai, Masato Tsuboi, Yoshiaki Sofue, Aya E. Higuchi, James O. Chibueze, Norikazu Mizuno, Mareki Honma, Erik Muller, Tsuyoshi Inoue, Kana Morokuma-Matsui, Hiroko Shinnaga, Takeaki Ozawa, Ryo Takahashi, Satoshi Yoshiike, Jean Costes, Sho Kuwahara .  FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45-m telescope (FUGIN) I: Project Overview and Initial Results .      2017年7月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45-m
    telescope (FUGIN) project is one of the legacy projects using the new
    multi-beam FOREST receiver installed on the Nobeyama 45-m telescope. This
    project aims to investigate the distribution, kinematics, and physical
    properties of both diffuse and dense molecular gas in the Galaxy at once by
    observing 12CO, 13CO, and C18O J=1-0 lines simultaneously. The mapping regions
    are a part of the 1st quadrant (10d < l < 50d, |b| < 1d) and the 3rd quadrant
    (198d < l <236d, |b| < 1d) of the Galaxy, where spiral arms, bar structure, and
    the molecular gas ring are included. This survey achieves the highest angular
    resolution to date (~20") for the Galactic plane survey in the CO J=1-0 lines,
    which makes it possible to find dense clumps located farther away than the
    previous surveys. FUGIN will provide us with an invaluable dataset for
    investigating the physics of the galactic interstellar medium (ISM),
    particularly the evolution of interstellar gas covering galactic scale
    structures to the internal structures of giant molecular clouds, such as small
    filament/clump/core. We present an overview of the FUGIN project, observation
    plan, and initial results, which reveal wide-field and detailed structures of
    molecular clouds, such as entangled filaments that have not been obvious in
    previous surveys, and large-scale kinematics of molecular gas such as spiral
    arms.

    DOI: 10.1093/pasj/psx061

    arXiv

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    その他リンク: http://arxiv.org/pdf/1707.05981v1

  • Kate Pattle, Derek Ward-Thompson, David Berry, Jennifer Hatchell, Huei-Ru Chen, Andy Pon, Patrick M. Koch, Woojin Kwon, Jongsoo Kim, Pierre Bastien, Jungyeon Cho, Simon Coudé, James Di Francesco, Gary Fuller, Ray S. Furuya, Sarah F. Graves, Doug Johnstone, Jason Kirk, Jungmi Kwon, Chang Won Lee, Brenda C. Matthews, Joseph C. Mottram, Harriet Parsons, Sarah Sadavoy, Hiroko Shinnaga, Archana Soam, Tetsuo Hasegawa, Shih-Ping Lai, Keping Qiu, Per Friberg .  The JCMT BISTRO Survey: The magnetic field strength in the Orion A filament .      2017年7月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We determine the magnetic field strength in the OMC 1 region of the Orion A
    filament via a new implementation of the Chandrasekhar-Fermi method using
    observations performed as part of the James Clerk Maxwell Telescope (JCMT)
    B-Fields In Star-Forming Region Observations (BISTRO) survey with the POL-2
    instrument. We combine BISTRO data with archival SCUBA-2 and HARP observations
    to find a plane-of-sky magnetic field strength in OMC 1 of $B_{\rm
    pos}=6.6\pm4.7$ mG, where $\delta B_{\rm pos}=4.7$ mG represents a
    predominantly systematic uncertainty. We develop a new method for measuring
    angular dispersion, analogous to unsharp masking. We find a magnetic energy
    density of $\sim1.7\times 10^{-7}$ Jm$^{-3}$ in OMC 1, comparable both to the
    gravitational potential energy density of OMC 1 ($\sim 10^{-7}$ Jm$^{-3}$), and
    to the energy density in the Orion BN/KL outflow ($\sim 10^{-7}$ Jm$^{-3}$). We
    find that neither the Alfv\'{e}n velocity in OMC 1 nor the velocity of the
    super-Alfv\'{e}nic outflow ejecta is sufficiently large for the BN/KL outflow
    to have caused large-scale distortion of the local magnetic field in the
    $\sim$500-year lifetime of the outflow. Hence, we propose that the hour-glass
    field morphology in OMC 1 is caused by the distortion of a primordial
    cylindrically-symmetric magnetic field by the gravitational fragmentation of
    the filament and/or the gravitational interaction of the BN/KL and S clumps. We
    find that OMC 1 is currently in or near magnetically-supported equilibrium, and
    that the current large-scale morphology of the BN/KL outflow is regulated by
    the geometry of the magnetic field in OMC 1, and not vice versa.

    DOI: 10.3847/1538-4357/aa80e5

    arXiv

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    その他リンク: http://arxiv.org/pdf/1707.05269v1

  • Derek Ward-Thompson, Kate Pattle, Pierre Bastien, Ray S. Furuya, Woojin Kwon, Shih-Ping Lai, Keping Qiu, David Berry, Minho Choi, Simon Coudé, James Di Francesco, Thiem Hoang, Erica Franzmann, Per Friberg, Sarah F. Graves, Jane S. Greaves, Martin Houde, Doug Johnstone, Jason M. Kirk, Patrick M. Koch, Jungmi Kwon, Chang Won Lee, Di Li, Brenda C. Matthews, Joseph C. Mottram, Harriet Parsons, Andy Pon, Ramprasad Rao, Mark Rawlings, Hiroko Shinnaga, Sarah Sadavoy, Sven van Loo, Yusuke Aso, Do-Young Byun, Eswariah Chakali, Huei-Ru Chen, Mike C. -Y. Chen, Wen Ping Chen, Tao-Chung Ching, Jungyeon Cho, Antonio Chrysostomou, Eun Jung Chung, Yasuo Doi, Emily Drabek-Maunder, Stewart P. S. Eyres, Jason Fiege, Rachel K. Friesen, Gary Fuller, Tim Gledhill, Matt J. Griffin, Qilao Gu, Tetsuo Hasegawa, Jennifer Hatchell, Saeko S. Hayashi, Wayne Holland, Tsuyoshi Inoue, Shu-ichiro Inutsuka, Kazunari Iwasaki, Il-Gyo Jeong, Ji-hyun Kang, Miju Kang, Sung-ju Kang, Koji S. Kawabata, Francisca Kemper, Gwanjeong Kim, Jongsoo Kim, Kee-Tae Kim, Kyoung Hee Kim, Mi-Ryang Kim, Shinyoung Kim, Kevin M. Lacaille, Jeong-Eun Lee, Sang-Sung Lee, Dalei Li, Hua-bai Li, Hong-Li Liu, Junhao Liu, Sheng-Yuan Liu, Tie Liu, A-Ran Lyo, Steve Mairs, Masafumi Matsumura, Gerald H. Moriarty-Schieven, Fumitaka Nakamura, Hiroyuki Nakanishi, Nagayoshi Ohashi, Takashi Onaka, Nicolas Peretto, Tae-Soo Pyo, Lei Qian, Brendan Retter, John Richer, Andrew Rigby, Jean-François Robitaille, Giorgio Savini, Anna M. M. Scaife, Archana Soam, Motohide Tamura, Ya-Wen Tang, Kohji Tomisaka, Hongchi Wang, Jia-Wei Wang, Anthony P. Whitworth, Hsi-Wei Yen, Hyunju Yoo, Jinghua Yuan, Chuan-Peng Zhang, Guoyin Zhang, Jianjun Zhou, Lei Zhu, Philippe André, C. Darren Dowell, Sam Falle, Yusuke Tsukamoto .  First results from BISTRO -- a SCUBA-2 polarimeter survey of the Gould Belt .      2017年4月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We present the first results from the B-fields In STar-forming Region
    Observations (BISTRO) survey, using the Sub-millimetre Common-User Bolometer
    Array 2 (SCUBA-2) camera, with its associated polarimeter (POL-2), on the James
    Clerk Maxwell Telescope (JCMT) in Hawaii. We discuss the survey's aims and
    objectives. We describe the rationale behind the survey, and the questions
    which the survey will aim to answer. The most important of these is the role of
    magnetic fields in the star formation process on the scale of individual
    filaments and cores in dense regions. We describe the data acquisition and
    reduction processes for POL-2, demonstrating both repeatability and consistency
    with previous data. We present a first-look analysis of the first results from
    the BISTRO survey in the OMC 1 region. We see that the magnetic field lies
    approximately perpendicular to the famous 'integral filament' in the densest
    regions of that filament. Furthermore, we see an 'hour-glass' magnetic field
    morphology extending beyond the densest region of the integral filament into
    the less-dense surrounding material, and discuss possible causes for this. We
    also discuss the more complex morphology seen along the Orion Bar region. We
    examine the morphology of the field along the lower-density north-eastern
    filament. We find consistency with previous theoretical models that predict
    magnetic fields lying parallel to low-density, non-self-gravitating filaments,
    and perpendicular to higher-density, self-gravitating filaments.

    DOI: 10.3847/1538-4357/aa70a0

    arXiv

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    その他リンク: http://arxiv.org/pdf/1704.08552v1

  • Ken'ichi Tatematsu, Tie Liu, Satoshi Ohashi, Patricio Sanhueza, Quang Nguyen-Luong, Tomoya Hirota, Sheng-Yuan Liu, Naomi Hirano, Minho Choi, Miju Kang, Mark Thompson, Garry Fuller, Yuefang Wu, James Di Francesco, Kee-Tae Kim, Ke Wang, Isabelle Ristorcelli, Mika Juvela, Hiroko Shinnaga, Maria R. Cunningham, Masao Saito, Jeong-Eun Lee, L. Viktor Toth, Jinhua He, Takeshi Sakai, Jungha Kim, JCMT Large Program "SCOPE" collaboration, TRAO Key Science Program "TOP" collaboration .  Astrochemical Properties of Planck Cold Clumps .      2016年12月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We observed thirteen Planck cold clumps with the James Clerk Maxwell
    Telescope/SCUBA-2 and with the Nobeyama 45 m radio telescope. The N$_2$H$^+$
    distribution obtained with the Nobeyama telescope is quite similar to SCUBA-2
    dust distribution. The 82 GHz HC$_3$N, 82 GHz CCS, and 94 GHz CCS emission are
    often distributed differently with respect to the N$_2$H$^+$ emission. The CCS
    emission, which is known to be abundant in starless molecular cloud cores, is
    often very clumpy in the observed targets. We made deep single-pointing
    observations in DNC, HN$^{13}$C, N$_2$D$^+$, cyclic-C$_3$H$_2$ toward nine
    clumps. The detection rate of N$_2$D$^+$ is 50\%. Furthermore, we observed the
    NH$_3$ emission toward 15 Planck cold clumps to estimate the kinetic
    temperature, and confirmed that most of targets are cold ($\lesssim$ 20 K). In
    two of the starless clumps observe, the CCS emission is distributed as it
    surrounds the N$_2$H$^+$ core (chemically evolved gas), which resembles the
    case of L1544, a prestellar core showing collapse. In addition, we detected
    both DNC and N$_2$D$^+$. These two clumps are most likely on the verge of star
    formation. We introduce the Chemical Evolution Factor (CEF) for starless cores
    to describe the chemical evolutionary stage, and analyze the observed Planck
    cold clumps.

    DOI: 10.3847/1538-4365/228/2/12

    arXiv

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    その他リンク: http://arxiv.org/pdf/1612.00488v1

  • Fumitaka Nakamura, Hideo Ogawa, Yoshinori Yonekura, Kimihiko Kimura, Nozomi Okada, Minato Kozu, Yutaka Hasegawa, Kazuki Tokuda, Tetsu Ochiai, Izumi Mizuno, Kazuhito Dobashi, Tomomi Shimoikura, Seiji Kameno, Kotomi Taniguchi, Hiroko Shinnaga, Shuro Takano, Ryohei Kawabe, Taku Nakajima, Daisuke Iono, Nario Kuno, Toshikazu Onishi, Munetake Momose, Satoshi Yamamoto .  Z45: A New 45-GHz Band Dual-Polarization HEMT Receiver for the NRO 45-m Radio Telescope .      2015年9月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We developed a dual-linear-polarization HEMT (High Electron Mobility
    Transistor) amplifier receiver system of the 45-GHz band (hereafter Z45), and
    installed it in the Nobeyama 45-m radio telescope. The receiver system is
    designed to conduct polarization observations by taking the cross correlation
    of two linearly-polarized components, from which we process full-Stokes
    spectroscopy. We aim to measure the magnetic field strength through the Zeeman
    effect of the emission line of CCS ($J_N=4_3-3_2$) toward pre-protostellar
    cores. A linear-polarization receiver system has a smaller contribution of
    instrumental polarization components to the Stokes $V$ spectra than that of the
    circular polarization system, so that it is easier to obtain the Stokes $V$
    spectra. The receiver has an RF frequency of 42 $-$ 46 GHz and an intermediate
    frequency (IF) band of 4$-$8 GHz. The typical noise temperature is about 50 K,
    and the system noise temperature ranges from 100 K to 150K over the frequency
    of 42 $-$ 46 GHz. The receiver system is connected to two spectrometers, SAM45
    and PolariS. SAM45 is a highly flexible FX-type digital spectrometer with a
    finest frequency resolution of 3.81 kHz. PolariS is a newly-developed digital
    spectrometer with a finest frequency resolution of 60 Hz, having a capability
    to process the full-Stokes spectroscopy. The Half Power Beam Width (HPBW) of
    the beam was measured to be 37$"$ at 43 GHz. The main beam efficiency of the
    Gaussian main beam was derived to be 0.72 at 43 GHz. The SiO maser observations
    show that the beam pattern is reasonably round at about 10 \% of the peak
    intensity and the side-lobe level was less than 3 \% of the peak intensity.
    Finally, we present some examples of astronomical observations using Z45.

    DOI: 10.1093/pasj/psv088

    arXiv

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    その他リンク: http://arxiv.org/pdf/1509.02631v1

  • Ray S. Furuya, Yoshimi Kitamura, Hiroko Shinnaga .  A Dynamically Collapsing Core and a Precursor of a Core in a Filament Supported by Turbulent and Magnetic Pressures .      2014年7月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    To study physical properties of the natal filament gas around the cloud core
    harboring an exceptionally young low-mass protostar GF9-2, we carried out J=1-0
    line observations of 12CO, 13CO, and C18O molecules using the Nobeyama 45m
    telescope. The mapping area covers ~1/5 of the whole filament. Our 13CO and
    C18O maps clearly demonstrate that the core formed at the local density maxima
    of the filament, and the internal motions of the filament gas are totally
    governed by turbulence with Mach number of ~2. We estimated the scale height of
    the filament to be H = 0.3 ~ 0.7 pc, yielding the central density of n_c = 700
    ~4200 cm^-3. Our analysis adopting an isothermal cylinder model shows that the
    filament is supported by the turbulent and magnetic pressures against the
    radial and axial collapse due to self-gravity. Since both the dissipation time
    scales of the turbulence and the transverse magnetic fields can be comparable
    to the free-fall time of the filament gas of 10^6 years, we conclude that the
    local decay of the supersonic turbulence made the filament gas locally
    unstable, hence making the core collapse. Furthermore, we newly detected a gas
    condensation with velocity width enhancement to ~0.3 pc south-west of the GF9-2
    core. The condensation has a radius of ~0.15 pc and an LTE mass of ~5 Msun. Its
    internal motion is turbulent with Mach number of ~3, suggestive of a
    gravitationally unbound state. Considering the uncertainties in our estimates,
    however, we propose that the condensation is a precursor of a cloud core which
    would have been produced by the collision of the two gas components identified
    in the filament.

    DOI: 10.1088/0004-637X/793/2/94

    arXiv

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    その他リンク: http://arxiv.org/pdf/1407.4857v1

  • Fumitaka Nakamura, Koji Sugitani, Tomohiro Tanaka, Hiroyuki Nishitani, Kazuhito Dobashi, Tomomi Shimoikura, Yoshito Shimajiri, Ryohei Kawabe, Yoshinori Yonekura, Izumi Mizuno, Kimihiko Kimura, Kazuki Tokuda, Minato Kozu, Nozomi Okada, Yutaka Hasegawa, Hideo Ogawa, Seiji Kameno, Hiroko Shinnaga, Munetake Momose, Taku Nakajima, Toshikazu Onishi, Hiroyuki Maezawa, Tomoya Hirota, Shuro Takano, Daisuke Iono, Nario Kuno, Satoshi Yamamoto .  Cluster Formation Triggered by Filament Collisions in Serpens South .      2014年7月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The Serpens South infrared dark cloud consists of several filamentary ridges,
    some of which fragment into dense clumps. On the basis of CCS ($J_N=4_3-3_2$),
    HC$_3$N ($J=5-4$), N$_2$H$^+$ ($J=1-0$), and SiO ($J=2-1, v=0$) observations,
    we investigated the kinematics and chemical evolution of these filamentary
    ridges. We find that CCS is extremely abundant along the main filament in the
    protocluster clump. We emphasize that Serpens South is the first
    cluster-forming region where extremely-strong CCS emission is detected. The
    CCS-to-N$_2$H$^+$ abundance ratio is estimated to be about 0.5 toward the
    protocluster clump, whereas it is about 3 in the other parts of the main
    filament. We identify six dense ridges with different $V_{\rm LSR}$. These
    ridges appear to converge toward the protocluster clump, suggesting that the
    collisions of these ridges may have triggered cluster formation. The collisions
    presumably happened within a few $\times \ 10^5$ yr because CCS is abundant
    only in such a short time. The short lifetime agrees with the fact that the
    number fraction of Class I objects, whose typical lifetime is $0.4 \times \
    10^5$ yr, is extremely high as about 70 percent in the protocluster clump. In
    the northern part, two ridges appear to have partially collided, forming a
    V-shape clump. In addition, we detected strong bipolar SiO emission that is due
    to the molecular outflow blowing out of the protostellar clump, as well as
    extended weak SiO emission that may originate from the filament collisions.

    DOI: 10.1088/2041-8205/791/2/L23

    arXiv

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    その他リンク: http://arxiv.org/pdf/1407.1235v1

  • Ian W. Stephens, Leslie W. Looney, Woojin Kwon, Charles L. H. Hull, Richard L. Plambeck, Richard M. Crutcher, Nicholas Chapman, Giles Novak, Jacqueline Davidson, John E. Vaillancourt, Hiroko Shinnaga, Tristan Matthews .  The Magnetic Field Morphology of the Class 0 Protostar L1157-mm .      2013年4月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We present the first detection of polarization around the Class 0 low-mass
    protostar L1157-mm at two different wavelengths. We show polarimetric maps at
    large scales (10" resolution at 350 um) from the SHARC-II Polarimeter and at
    smaller scales (1.2"-4.5" at 1.3 mm) from the Combined Array for Research in
    Millimeter-wave Astronomy (CARMA). The observations are consistent with each
    other and show inferred magnetic field lines aligned with the outflow. The
    CARMA observations suggest a full hourglass magnetic field morphology centered
    about the core; this is only the second well-defined hourglass detected around
    a low-mass protostar to date. We apply two different methods to CARMA
    polarimetric observations to estimate the plane-of-sky magnetic field
    magnitude, finding values of 1.4 and 3.4 mG.

    DOI: 10.1088/2041-8205/769/1/L15

    arXiv

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    その他リンク: http://arxiv.org/pdf/1304.6739v1

  • Hiroko Shinnaga, Giles Novak, John E. Vaillancourt, Masahiro N. Machida, Akimasa Kataoka, Kohji Tomisaka, Jacqueline Davidson, Thomas G. Phillips, C. Darren Dowell, Lerothodi Leeuw, Martin Houde .  Magnetic Field in The Isolated Massive Dense Clump IRAS 20126+4104 .      2012年3月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We measured polarized dust emission at 350um towards the high-mass star
    forming massive dense clump IRAS 20126+4104 using the SHARC II Polarimeter,
    SHARP, at the Caltech Submillimeter Observatory. Most of the observed magnetic
    field vectors agree well with magnetic field vectors obtained from a numerical
    simulation for the case when the global magnetic field lines are inclined with
    respect to the rotation axis of the dense clump. The results of the numerical
    simulation show that rotation plays an important role on the evolution of the
    massive dense clump and its magnetic field. The direction of the cold CO 1-0
    bipolar outflow is parallel to the observed magnetic field within the dense
    clump as well as the global magnetic field, as inferred from optical
    polarimetry data, indicating that the magnetic field also plays a critical role
    in an early stage of massive star formation. The large-scale Keplerian disk of
    the massive (proto)star rotates in almost opposite sense to the clump's
    envelope. The observed magnetic field morphology and the counter-rotating
    feature of the massive dense clump system provide hints to constrain the role
    of magnetic fields in the process of high mass star formation.

    DOI: 10.1088/2041-8205/750/2/L29

    arXiv

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    その他リンク: http://arxiv.org/pdf/1203.3211v1

  • Hiroko Shinnaga, Thomas G. Phillips, Ray S. Furuya, Yoshimi Kitamura .  Warm Extended Dense Gas Lurking At The Heart Of A Cold Collapsing Dense Core .      2009年10月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    In order to investigate when and how the birth of a protostellar core occurs,
    we made survey observations of four well-studied dense cores in the Taurus
    molecular cloud using CO transitions in submillimeter bands. We report here the
    detection of unexpectedly warm (~ 30 - 70 K), extended (radius of ~ 2400 AU),
    dense (a few times 10^{5} cm^{-3}) gas at the heart of one of the dense cores,
    L1521F (MC27), within the cold dynamically collapsing components. We argue that
    the detected warm, extended, dense gas may originate from shock regions caused
    by collisions between the dynamically collapsing components and
    outflowing/rotating components within the dense core. We propose a new stage of
    star formation, "warm-in-cold core stage (WICCS)", i.e., the cold collapsing
    envelope encases the warm extended dense gas at the center due to the formation
    of a protostellar core. WICCS would constitutes a missing link in evolution
    between a cold quiescent starless core and a young protostar in class 0 stage
    that has a large-scale bipolar outflow.

    DOI: 10.1088/0004-637X/706/2/L226

    arXiv

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    その他リンク: http://arxiv.org/pdf/0910.0463v1

  • Ray S. Furuya, Hiroko Shinnaga .  High Velocity Outflow in CO J=7-6 from the Orion Hot Core .      2009年8月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Using the Caltech Submillimeter Observatory 10.4-meter telescope, we
    performed sensitive mapping observations of 12CO J=7-6 emission at 807 GHz
    towards Orion IRc2. The image has an angular resolution of 10", which is the
    highest angular resolution data toward the Orion Hot Core published for this
    transition. In addition, thanks to the on-the-fly mapping technique, the
    fidelity of the new image is rather high, particularly in comparison to
    previous images. We have succeeded in mapping the northwest-southeast
    high-velocity molecular outflow, whose terminal velocity is shifted by ~70-85
    km/s with respect to the systemic velocity of the cloud. This yields an
    extremely short dynamical time scale of ~900 years. The estimated outflow mass
    loss rate shows an extraordinarily high value, on the order of 10^{-3} Msun/yr.
    Assuming that the outflow is driven by Orion IRc2, our result agrees with the
    picture so far obtained for a 20 Msun (proto)star in the process of formation.

    DOI: 10.1088/0004-637X/703/2/1198

    arXiv

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    その他リンク: http://arxiv.org/pdf/0908.0317v1

  • Michael Attard, Martin Houde, Giles Novak, Hua-bai Li, John E. Vaillancourt, C. Darren Dowell, Jacqueline Davidson, Hiroko Shinnaga .  Magnetic Fields and Infall Motions in NGC 1333 IRAS 4 .      2009年7月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We present single-dish 350 micron dust continuum polarimetry as well as HCN
    and HCO+ J=4-3 rotational emission spectra obtained on NGC 1333 IRAS 4. The
    polarimetry indicates a uniform field morphology over a 20" radius from the
    peak continuum flux of IRAS 4A, in agreement with models of magnetically
    supported cloud collapse. The field morphology around IRAS 4B appears to be
    quite distinct however, with indications of depolarization observed towards the
    peak flux of this source. Inverse P-Cygni profiles are observed in the HCN
    J=4-3 line spectra towards IRAS 4A, providing a clear indication of infall gas
    motions. Taken together, the evidence gathered here appears to support the
    scenario that IRAS 4A is a cloud core in a critical state of support against
    gravitational collapse.

    DOI: 10.1088/0004-637X/702/2/1584

    arXiv

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    その他リンク: http://arxiv.org/pdf/0907.1301v1

  • Hiroko Shinnaga, Ken H. Young, Remo P. J. Tilanus, Richard Chamberlin, Mark A. Gurwell, David Wilner, A. Meredith Hughes, Hiroshige Yoshida, Ruisheng Peng, Brian Force, Per Friberg, Sandrine Bottinelli, Ewine F. Van Dishoeck, Thomas G. Phillips .  IRC+10216's Innermost Envelope -- The eSMA's View .      2009年4月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We used the Extended Submillimeter Array (eSMA) in its most extended
    configuration to investigate the innermost (within a radius of 290 R* from the
    star) circumstellar envelope (CSE) of IRC+10216. We imaged the CSE using HCN
    and other molecular lines with a beam size of 0."22 x 0."46, deeply into the
    very inner edge (15 R*) of the envelope where the expansion velocity is only 3
    km/s. The excitation mechanism of hot HCN and KCl maser lines is discussed. HCN
    maser components are spatially resolved for the first time on an astronomical
    object. We identified two discrete regions in the envelope: a region with a
    radius of . 15 R*, where molecular species have just formed and the gas has
    begun to be accelerated (region I) and a shell region (region II) with a radius
    of 23 R* and a thickness of 15 R*, whose expansion velocity has reached up to
    13 km/s, nearly the terminal velocity of 15 km/s. The Si$^{34}$S line detected
    in region I shows a large expansion velocity of 16 km/s due to strong wing
    components, indicating that the emission may arise from a shock region in the
    innermost envelope. In region II, the P.A. of the most copious mass loss
    direction was found to be 120 +/- 10 degrees, which may correspond to the
    equatorial direction of the star. Region II contains a torus-like feature.
    These two regions may have emerged due to significant differences in the size
    distributions of the dust particles in the two regions.

    DOI: 10.1088/0004-637X/698/2/1924

    DOI: 10.1088/0004-637X/727/1/60

    arXiv

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    その他リンク: http://arxiv.org/pdf/0904.0280v1

  • Dean C. Hines, Christopher C. Packham, Andy Adamson, B. -G. Andersson, Robert Antonucci, David Axon, James De Buizer, Alberto Cellino, Dan Clemens, Jennifer L. Hoffman, Makoto Kishimoto, Terry Jay Jones, Alexander Lazarian, Antonio Mario Magalhaes, Joseph Masiero, Eric S. Perlman, Marshall Perrin, Claudia Vilega Rodrigues, Hiroko Shinnaga, William Sparks, Doug Whittet .  O/IR Polarimetry for the 2010 Decade (CGT): Science at the Edge, Sharp Tools for All .      2009年2月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Science opportunities and recommendations concerning optical/infrared
    polarimetry for the upcoming decade in the field of extragalactic astrophysics.
    Community-based White Paper to Astro2010 in response to the call for such
    papers.

    arXiv

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    その他リンク: http://arxiv.org/pdf/0902.4224v1

  • Jennifer L. Hoffman, Dean C. Hines, Andy Adamson, B. -G. Andersson, Karen Bjorkman, Ryan Chornock, Dan Clemens, James De Buizer, Nicholas M. Elias II, Richard Ignace, Terry Jay Jones, Alexander Lazarian, Douglas C. Leonard, Antonio Mario Magalhaes, Marshall Perrin, Claudia Vilega Rodrigues, Hiroko Shinnaga, William Sparks, Lifan Wang .  O/IR Polarimetry for the 2010 Decade (SSE): Science at the Edge, Sharp Tools for All .      2009年2月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Science opportunities and recommendations concerning optical/infrared
    polarimetry for the upcoming decade in the fields of stars and stellar
    evolution. Community-based White Paper to Astro2010 in response to the call for
    such papers.

    arXiv

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    その他リンク: http://arxiv.org/pdf/0902.4222v1

  • Dan Clemens, B. -G. Andersson, Andy Adamson, David Axon, James De Buizer, Alberto Cellino, Dean C. Hines, Jennifer L. Hoffman, Terry Jay Jones, Alexander Lazarian, Antonio Mario Magalhaes, Joseph Masiero, Chris Packham, Marshall Perrin, Claudia Vilega Rodrigues, Hiroko Shinnaga, William Sparks, John Vaillancourt, Doug Whittet .  O/IR Polarimetry for the 2010 Decade (PSF): Science at the Edge, Sharp Tools for All .      2009年2月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Science opportunities and recommendations concerning optical/infrared
    polarimetry for the upcoming decade in the fields of planetary systems and star
    formation. Community-based White Paper to Astro2010 in response to the call for
    such papers.

    arXiv

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    その他リンク: http://arxiv.org/pdf/0902.4220v1

  • Dan Clemens, B. -G. Andersson, Andy Adamson, David Axon, James De Buizer, Alberto Cellino, Dean C. Hines, Jennifer L. Hoffman, Terry Jay Jones, Alexander Lazarian, Antonio Mario Magalhaes, Joseph Masiero, Chris Packham, Marshall Perrin, Claudia Vilega Rodrigues, Hiroko Shinnaga, William Sparks, John Vaillancourt, Doug Whittet .  O/IR Polarimetry for the 2010 Decade (GAN): Science at the Edge, Sharp Tools for All .      2009年2月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Science opportunities and recommendations concerning optical/infrared
    polarimetry for the upcoming decade in the field of Galactic science.
    Community-based White Paper to Astro2010 in response to the call for such
    papers.

    arXiv

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    その他リンク: http://arxiv.org/pdf/0902.4217v1

  • Alex Lazarian, Dan Clemens, Andy Adamson, B. -G. Andersson, David Axon, James De Buizer, Alberto Cellino, Dean C. Hines, Jennifer L. Hoffman, Terry Jay Jones, Antonio Mario Magalhaes, Joseph Masiero, Chris Packham, Marshall Perrin, Claudia Vilega Rodrigues, Hiroko Shinnaga, William Sparks, John Vaillancourt, Doug Whittet .  Understanding Polarized Foreground from Dust: Towards Reliable Measurements of CMB Polarization .      2009年2月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Science opportunities and recommendations concerning optical/infrared
    polarimetry for the upcoming decade in the field of cosmology. Community-based
    White Paper to Astro2010 in response to the call for such papers.

    arXiv

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    その他リンク: http://arxiv.org/pdf/0902.4226v1

  • Ray S. Furuya, Yoshimi Kitamura, Hiroko Shinnaga .  Spectroscopic Evidence for Gas Infall in GF9-2 .      2009年1月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We present spectroscopic evidence for infall motion of gas in the natal cloud
    core harboring an extremely young low-mass protostar GF9-2. We previously
    discussed that the ongoing collapse of the GF9-2 core has agreement with the
    Larson-Penston-Hunter (LPH) theoretical solution for the gravitational collapse
    of a core (Furuya et al.; paper I). To discuss the gas infall on firmer ground,
    we have carried out On-The-Fly mapping observations of the HCO+ (1--0) line
    using the Nobeyama 45m telescope equipped with the 25 Beam Array Receiver
    System. Furthermore, we observed the HCN (1--0) line with the 45m telescope,
    and the HCO+ (3--2) line with the Caltech Submillimeter Observatory 10.4 m
    telescope. The optically thick HCO+ and HCN lines show blueskewed profiles
    whose deepest absorptions are seen at the peak velocity of optically thin
    lines, i.e., the systemic velocity of the cloud (paper I), indicating the
    presence of gas infall toward the central protostar. We compared the observed
    HCO+ line profiles with model ones by solving the radiative transfer in the
    core under LTE assumption.We found that the core gas has a constant infall
    velocity of ~0.5 km/s in the central region, leading to a mass accretion rate
    of 2.5x10^{-5} Msun/yr. Consequently, we confirm that the gas infall in the
    GF9-2 core is consistent with the LPH solution.

    DOI: 10.1088/0004-637X/692/2/L96

    arXiv

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    その他リンク: http://arxiv.org/pdf/0901.0730v1

  • Sandrine Bottinelli, A. Meredith Hughes, Ewine F. van Dishoeck, Ken H. Young, Richard Chamberlin, Remo P. J. Tilanus, Mark A. Gurwell, David J. Wilner, Huib Jan van Langevelde, Michiel R. Hogerheijde, Robert D. Christensen, Hiroko Shinnaga, Hiroshige Yoshida .  Detection of CI in absorption towards PKS 1830-211 with the eSMA .      2008年11月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We report the first science observations and results obtained with the
    "extended" SMA (eSMA), which is composed of the SMA (Submillimeter Array), JCMT
    (James Clerk Maxwell Telescope) and CSO (Caltech Submillimeter Observatory).
    Redshifted absorptions at z=0.886 of CI (^3P_1 - ^3P_0) were observed with the
    eSMA with an angular resolution of 0.55"x0.22" at 1.1 mm toward the
    southwestern image of the remarkable lensed quasar PKS 1830-211, but not toward
    the northeastern component at a separation of ~1". Additionally, SMA
    observations of CO, 13CO and C18O (all J=4-3) were obtained toward this object:
    CO was also detected toward the SW component, but none of the isotopologues
    were. This is the first time [CI] is detected in this object, allowing the
    first direct determination of relative abundances of neutral atomic carbon to
    CO in the molecular clouds of a spiral galaxy at z>0.1. The [CI] and CO
    profiles can be decomposed into two and three velocity components respectively.
    We derive C/CO column density ratios ranging from <0.5 (representative of dense
    cores) to ~2.5 (close to translucent clouds values). This could indicate that
    we are seeing environments with different physical conditions or that we are
    witnessing chemical evolution of regions where C has not completely been
    converted into CO.

    DOI: 10.1088/0004-637X/690/2/L130

    arXiv

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    その他リンク: http://arxiv.org/pdf/0811.3944v1

  • Sandrine Bottinelli, Ken H. Young, Richard Chamberlin, Remo P. J. Tilanus, Mark A. Gurwell, Dave J. Wilner, Hiroko Shinnaga, Hiroshige Yoshida, Per Friberg, Huib Jan van Langevelde, Ewine F. van Dishoeck, Michiel R. Hogerheijde, A. Meredith Hughes, Robert D. Christensen, Richard E. Hills, John S. Richer, Emily Curtis, the eSMA commissioning team .  The eSMA: description and first results .      2008年8月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The eSMA ("extended SMA") combines the SMA, JCMT and CSO into a single
    facility, providing enhanced sensitivity and spatial resolution owing to the
    increased collecting area at the longest baselines. Until ALMA early science
    observing (2011), the eSMA will be the facility capable of the highest angular
    resolution observations at 345 GHz. The gain in sensitivity and resolution will
    bring new insights in a variety of fields, such as protoplanetary/transition
    disks, high-mass star formation, solar system bodies, nearby and high-z
    galaxies. Therefore the eSMA is an important facility to prepare the grounds
    for ALMA and train scientists in the techniques.
    Over the last two years, and especially since November 2006, there has been
    substantial progress toward making the eSMA into a working interferometer. In
    particular, (i) new 345-GHz receivers, that match the capabilities of the SMA
    system, were installed at the JCMT and CSO; (ii) numerous tests have been
    performed for receiver, correlator and baseline calibrations in order to
    determine and take into account the effects arising from the differences
    between the three types of antennas; (iii) first fringes at 345 GHz were
    obtained on August 30 2007, and the array has entered the science-verification
    stage.
    We report on the characteristics of the eSMA and its measured performance at
    230 GHz and that expected at 345 GHz. We also present the results of the
    commissioning and some initial science-verification observations, including the
    first absorption measurement of the C/CO ratio in a galaxy at z=0.89, located
    along the line of sight to the lensed quasar PKS1830-211, and on the imaging of
    the vibrationally excited HCN line towards IRC+10216.

    DOI: 10.1117/12.788949

    arXiv

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    その他リンク: http://arxiv.org/pdf/0808.2554v1

  • Ray S. Furuya, Yoshimi Kitamura, Hiroko Shinnaga .  Low-Mass Star Forming Cores in the GF9 Filament .      2008年4月国際共著 国際誌

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We carried out an unbiased mapping survey of dense molecular cloud cores
    traced by the NH3 (1,1) and (2,2) inversion lines in the GF9 filament which
    contains an extremely young low-mass protostar GF9-2 (Furuya et al. 2006, ApJ,
    653, 1369). The survey was conducted using the Nobeyama 45m telescope over a
    region of ~1.5 deg with an angular resolution of 73". The large-scale map
    revealed that the filament contains at least 7 dense cores, as well as 3
    possible ones, located at regular intervals of ~0.9 pc. Our analysis shows that
    these cores have kinetic temperatures of $\lesssim$ 10 K and LTE-masses of 1.8
    -- 8.2 Msun, making them typical sites of low-mass star formation. All the
    identified cores are likely to be gravitationally unstable because their
    LTE-masses are larger than their virial masses. Since the LTE-masses and
    separations of the cores are consistent with the Jeans masses and lengths,
    respectively, for the low-density ambient gas, we argue that the identified
    cores have formed via the gravitational fragmentation of the natal filamentary
    cloud.

    DOI: 10.1093/pasj/60.3.421

    arXiv

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    その他リンク: http://arxiv.org/pdf/0805.0021v1

  • Hiroko Shinnaga, Thomas G. Phillips, Ray S. Furuya, Riccardo Cesaroni .  Submillimeter Observations of The Isolated Massive Dense Clump IRAS 20126+4104 .      2008年4月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We used the CSO 10.4 meter telescope to image the 350 micron and 450 micron
    continuum and CO J=6-5 line emission of the IRAS 20126+4104 clump. The
    continuum and line observations show that the clump is isolated over a 4 pc
    region and has a radius of ~ 0.5 pc. Our analysis shows that the clump has a
    radial density profile propto r ^{-1.2} for r <~ 0.1 pc and has propto r^{-2.3}
    for r >~ 0.1 pc which suggests the inner region is infalling, while the infall
    wave has not yet reached the outer region. Assuming temperature gradient of
    r^{-0.35}, the power law indices become propto r ^{-0.9} for r < ~0.1 pc and
    propto r^{-2.0} for r >~ 0.1 pc. Based on a map of the flux ratio of
    350micron/450micron, we identify three distinct regions: a bipolar feature that
    coincides with the large scale CO bipolar outflow; a cocoon-like region that
    encases the bipolar feature and has a warm surface; and a cold layer outside of
    the cocoon region. The complex patterns of the flux ratio map indicates that
    the clump is no longer uniform in terms of temperature as well as dust
    properties. The CO emission near the systemic velocity traces the dense clump
    and the outer layer of the clump shows narrow line widths (< ~3 km/s). The
    clump has a velocity gradient of ~ 2 km/s pc^{-1}, which we interpret as due to
    rotation of the clump, as the equilibrium mass (~ 200 Msun) is comparable to
    the LTE mass obtained from the CO line. Over a scale of ~ 1 pc, the clump
    rotates in the opposite sense with respect to the >~ 0.03 pc disk associated
    with the (proto)star. This is one of four objects in high-mass and low-mass
    star forming regions for which a discrepancy between the rotation sense of the
    envelope and the core has been found, suggesting that such a complex kinematics
    may not be unusual in star forming regions.

    DOI: 10.1086/589279

    arXiv

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    その他リンク: http://arxiv.org/pdf/0804.1804v1

  • Jonathan Weintroub, James M. Moran, David J. Wilner, Ken H. Young, Ramprasad Rao, Hiroko Shinnaga .  SMA Imaging of the Maser Emission from the H30$α$ Radio Recombination Line in MWC349A .      2008年1月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We used the Submillimeter Array to map the angular distribution of the
    H30$\alpha$ recombination line (231.9 GHz) in the circumstellar region of the
    peculiar star MWC349A. The resolution was $1\farcs2$, but because of high
    signal-to-noise ratio we measured the positions of all maser components to
    accuracies better than $0\farcs01$, at a velocity resolution of $1 kms$. The
    two strongest maser components (called high velocity components) at velocities
    near -14 and $32 kms$ are separated by $0\farcs048 \pm 0\farcs001$ (60 AU)
    along a position angle of $102 \pm 1\arcdeg$. The distribution of maser
    emission at velocities between and beyond these two strongest components were
    also provided. The continuum emission lies at the center of the maser
    distribution to within 10 mas. The masers appear to trace a nearly edge-on
    rotating disk structure, reminiscent of the water masers in Keplerian rotation
    in the nuclear accretion disk of the galaxy NGC4258. However, the maser
    components in MWC349A do not follow a simple Keplerian kinematic prescription
    with $v \sim r^{-1/2}$, but have a larger power law index. We explore the
    possibility that the high velocity masers trace spiral density or shock waves.
    We also emphasize caution in the interpretation of relative centroid maser
    positions where the maser is not clearly resolved in position or velocity, and
    we present simulations that illustrate the range of applicability of the
    centroiding method.

    DOI: 10.1086/529132

    arXiv

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    その他リンク: http://arxiv.org/pdf/0801.0608v1

  • Ray S. Furuya, Yoshimi Kitamura, Hiroko Shinnaga .  The Initial Conditions for Gravitational Collapse of a Core: An Extremely Young Low-Mass Class 0 Protostar GF9-2 .      2006年8月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We present a study of the natal core harboring the class 0 protostar GF9-2 in
    the filamentary dark cloud GF 9 (d = 200 pc). GF9-2 stands unique in the sense
    that it shows H2O maser emission, a clear signpost of protostar formation,
    whereas it does not have a high-velocity large-scale molecular outflow
    evidenced by our deep search for CO wing emission. These facts indicate that
    GF9-2 core is early enough after star formation so that it still retains some
    information of initial conditions for collapse. Our 350 um dust continuum
    emission image revealed the presence of a protostellar envelope in the center
    of a molecular core. The mass of the envelope is ~0.6 Msun from the 350 um flux
    density, while LTE mass of the core is ~3 Msun from moleuclar line
    observations. Combining visibility data from the OVRO mm-array and the 45m
    telescope, we found that the core has a radial density profile of
    $\rho(r)\propto r^{-2}$ for 0.003 < r/pc < 0.08 region. Molecular line data
    analysis revealed that the velocity width of the core gas increases
    inward,while the outermost region maintains a velocity dispersion of a few
    times of the ambient sound speed. The broadened velocity width can be
    interpreted as infall. Thus, the collapse in GF9-2 is likely to be described by
    an extension of the Larson-Penston solution for the period after formation of a
    central star. We derived the current mass accretion rate of ~3E-05 Msun/year
    from infall velocity of ~ 0.3 km/s at r~ 7000 AU. All results suggest that
    GF9-2 core has been undergoing gravitational collapse for ~ 5000 years since
    the formation of central protostar(s), and that the unstable state initiated
    the collapse ~2E+05 years (the free-fall time) ago.

    DOI: 10.1086/508405

    arXiv

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    その他リンク: http://arxiv.org/pdf/astro-ph/0608357v1

  • Hiroko Shinnaga, James M. Moran, Ken H. Young, Paul T. P. Ho .  Interferometric Observation of the Highly Polarized SiO Maser Emission from the $v=1, J=5-4$ Transition Associated with VY Canis Majoris .      2004年8月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We used the Submillimeter Array to image the SiO maser emission in the $v=1$,
    \$J=5-4$ transition associated with the peculiar red supergiant VY Canis
    Majoris. We identified seven maser components and measured their relative
    positions and linear polarization properties. Five of the maser components are
    coincident to within about 150 mas ($\sim$ 200 AU at the distance of 1.5 kpc);
    most of them may originate in the circumstellar envelope at a radius of about
    50 mas from the star along with the SiO masers in the lowest rotational
    transitions. Our measurements show that two of the maser components may be
    offset from the inner stellar envelope (at the 3$\sigma$ level of significance)
    and may be part of a larger bipolar outflow associated with VY CMa identified
    by Shinnaga et al. The strongest maser feature at a velocity of 35.9 kms$^{-1}$
    has a 60 percent linear polarization, and its polarization direction is aligned
    with the bipolar axis. Such a high degree of polarization suggests that maser
    inversion is due to radiative pumping. Five of the other maser features have
    significant linear polarization.

    DOI: 10.1086/425133

    arXiv

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    その他リンク: http://arxiv.org/pdf/astro-ph/0408298v2

  • Naomi Hirano, Hiroko Shinnaga, Dinh-V-Trung, David Fong, Eric Keto, Nimesh Patel, Chunhua Qi, Ken Young, Qizhou Zhang, Junhui Zhao .  High velocity bipolar outflow and disk-like envelope in the carbon star V Hya .      2004年7月国際共著 国際誌

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Using the partially completed Submillimeter Array with five antennas, we have
    observed the CO J=2-1 and 3-2 emission from the envelope surrounding the carbon
    star V Hya. The high-angular resolution (2"-4") maps show that V Hya is
    powering a bipolar molecular jet having an extreme velocity of 70-185 km/s. The
    axis of this high velocity jet is perpendicular to the major axis of the
    flattened disk-like envelope, which is expanding with a velocity of ~16
    km/s.There is a third kinematic component, a medium-velocity wind having a
    deprojected velocity of 40-120 km/s moving along the disk plane. Both the high
    velocity jet and the medium velocity wind have a dynamical time scale of a few
    hundred years. The flattened structure and the collimated jet observed in V Hya
    suggests that the formation of asymmetrical structure proceeds while the
    central star is still in the AGB phase

    DOI: 10.1086/424382

    arXiv

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    その他リンク: http://arxiv.org/pdf/astro-ph/0407337v1

▼全件表示

書籍等出版物

  • 星間物質と星形成

    福井康雄他( 担当: 共著 ,  範囲: 星間磁場)

    日本評論社  2008年9月 

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    総ページ数:325   担当ページ:166-175   記述言語:日本語 著書種別:学術書

講演・口頭発表等

  • Hiroko Shinnaga, Mark J. Claussen, Hiroshi Imai, Miyako Oyadomari, Takeru Suzuki, Anita M.S. Richards, Malcolm D. Gray, Sandra Etoka, Satoshi Yamamoto, Masumi Shimojo, and Koji Murakawa .  Dynamic Mass Outflow and Circumstellar Magnetic Field of A Red Supergiant .  IAU Symposium 360 Astronomical Polarimetry 2020: New Era of Multiwavelength Polarimetry  2021年  IAU Symposium 360 Science Organizing Committee国際共著

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    開催年月日: 2021年3月

    記述言語:英語   会議種別:口頭発表(一般)  

    開催地:Hiroshima, Japan   国名:日本国  

  • Hiroko Shinnaga et al. .  Innermost Circumstellar Envelope of The Extreme Red Supergiant VY Canis Majoris .  The 32nd Annual New Mexico Symposium  National Radio Astronomy Observatory (NRAO)国際会議

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    開催年月日: 2016年11月

    記述言語:英語   会議種別:口頭発表(一般)  

    開催地:Socorro, NM, U.S.A.  

受賞

  • IAU Symposium 360

    2019年5月   国際天文学連合   Astronomical Polarimetry 2020 -- New Era of Multi-Wavelength Polarimetry

    Hiroko Shinnaga (Chair, Kagoshima University Japan, B.-G. Andersson (Co-chair, Universities Space Research Association USA, Antonio Mario, Magalhães (Co-chair, Universidade de São Paulo, Brazil, Francois Menard, Co-chair, Institut de Planétologie et, d’Astrophysique de Grenoble France, Edith Falgarone, PSL Research University France, Jennifer L. Hoffman, University of Denver, USA Masateru Ishiguro, Seoul National University Korea Koji S. Kawabata, Hiroshima University Japan, Masafumi Matsumura, Kagawa University Japan, Thushara Pillai, Max Planck Institute for, Radioastronomy U.S.A, Stephen Potter, South African Astronomical Observatory, South Africa, Claudia V. Rodrigues, Instituto Nacional de, Pesquisas Espaciais, Brazil, Motohide Tamura, University of Tokyo, Japan

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  • Center for Astrophysics Postdoctoral Fellow

    2001年   ハーバード大学観測所ースミソニアン天体物理観測所  

    新永 浩子

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共同研究・競争的資金等の研究

  • 星形成領域、晩期型星星周領域における磁場の役割の研究

    研究課題/領域番号:17K05388  2017年4月 - 2021年3月

    日本学術振興会  科学研究費助成事業 基盤研究(C)  基盤研究(C)

    新永 浩子

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    配分額:4550000円 ( 直接経費:3500000円 、 間接経費:1050000円 )

    昨年度はJVLAを用いた赤色超巨星のおおいぬ座VY星(VY CMa)の星周領域の観測を2つの配列(広がった成分検出のD配列、及び コンパクト成分観測のB配列)で提案した。D配列は高評価で提案が採択され、データは取得済だが、コロナウィルス問題のため、観測所を訪問してデータの詳細な解析、議論する過程が現在、未完了である。B配列については、フィラー観測として採択され、コロナウィルスの影響で延期されていたB配列の開始は20年6月中旬以降の予定である。
    VERAの同星のSiO分子の振動励起状態v=0, 1, 2, 3 の4輝線同時観測はデータ解析を完了し、現在成論文を投稿準備中である。v=3の5000Kを超えるエネルギー準位の輝線イメージングの成功に加え、通常は熱的励起の広がったv=0の輝線であるが、高い直線偏波率を示す同星のv=0輝線のVLBIでの非常にコンパクトな成分の検出は、今までの常識を覆す成果である。この成果は、未解決だったv=0メーザーの起源を解き明かす重要なデータであり、宇宙メーザーの研究をリードする成果の一つとなる。
    同星星周領域で明るい、MERLIN望遠鏡による3つのOH分子輝線のデータ解析が進行中で、3-4秒角に渡って広がった、数十のクランプの中から、磁場強度測定の候補成分を選び出す。VLA望遠鏡(B配列)で検出したSiO v=0輝線の分布範囲(2秒角程度)の2倍程度の広がりを持つ。今年度は、JVLAによる新たな観測データの解析に加えて、これまでの成果をまとめた論文出版を行う。コロナウィルスの影響による研究の遅れを取り戻すことを目標に、本研究プロジェクトの総括へ向けて進める。
    2019年度に採択されたIAUシンポジウム(Astropol2020)はコロナウィルスのため、会期を遅らせることを決定したが、本研究の成果も今年度に予定する同シンポジウムで発表する予定である。

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  • 多波長帯電波同時高解像度撮像による星周物質の合成・加速過程の探求

    研究課題/領域番号:16H02167  2016年4月 - 2020年3月

    日本学術振興会  科学研究費助成事業 基盤研究(A)  基盤研究(A)

    今井 裕, 朝木 義晴, 河野 裕介, 小川 英夫, 新永 浩子

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    配分額:46670000円 ( 直接経費:35900000円 、 間接経費:10770000円 )

    本研究課題では、野辺山45m電波望遠鏡の3周波数帯同時観測システムの構築に成功した。その中で、開発した周波数分離板が、特に高周波数帯側における電波透過率やポインティングずれについて、期待される性能が出ていることを確認した。早速このシステムの一部を使って、終末星ジェットの発現や、星周メーザー源の周期的な視線速度変動を捉えた。また、東アジアVLBI観測網を用いた星周メーザー源の連続撮像観測を遂行した。その中で、星の脈動変光と星周縁内の衝撃波伝播に対して、水及び複数の一酸化珪素メーザー輝線においてそれぞれ異なった時間変動の振る舞いを連続的に追跡することができた。

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  • なぜ星形成には孤立的と集団的の2つのモードがあるのか?

    研究課題/領域番号:20740113  2008年 - 2009年

    日本学術振興会  科学研究費助成事業 若手研究(B)  若手研究(B)

    古屋 玲, 北村 良実, 新永 浩子, チェザローニ リッカルド

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    配分額:2860000円 ( 直接経費:2200000円 、 間接経費:660000円 )

    分子雲コアが重力収縮する際の初期条件及び境界条件(まとめて環境条件)の違いに着目して、何が孤立的な星形成と集団的な星形成へ至る運命をわけているのかを調べた。本研究では、さまざまな質量の原始星及び原始星候補天体群について、その誕生前後の進化の様子を観測的に調べることに集中した。この結果、中心星への質量降着現象の多様性の起源について、環境条件の観点から理解を深めることができた。

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担当経験のある授業科目

  • Advanced Studies of Observational Astronomy

    2017年
    -
    現在
    機関名:鹿児島大学

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  • 宇宙の誕生と進化−私たちの起源

    2013年
    -
    2014年
    機関名:放送大学 東京渋谷学習センター

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    科目区分:学部教養科目  国名:日本国

  • Stellar Astronomy

    2012年
    機関名:ハワイ大学 ヒロ校

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    国名:アメリカ合衆国

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メディア報道

  • 巨大星の最期・超新星爆発直前にとらえた強力な磁場

    日本天文学会  しんぶん赤旗  オックスフォード大学出版局 @OUPAcJapan  2018年3月

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    執筆者:本人 

学術貢献活動

  • 国際天文学連合シンポジウム360 偏波・偏光 天文シンポジウム2020 国際学術貢献

    役割:企画立案・運営等, パネル司会・セッションチェア等, 監修, 審査・評価, 学術調査立案・実施, 査読

    新永 浩子  ( 東広島 芸術文化ホール くらら ) 2021年3月

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    種別:大会・シンポジウム等 

    天文学分野の偏波・偏光に関連した研究者が世界各地から参加し、宇宙開闢の歴史から太陽系小天体の性質まで、非常に幅広い天文学の内容について、活発な議論を行う。

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