田中　邦彦 (タナカ　クニヒコ)

Tanaka, Kunihiko

写真a

所属（所属キャンパス）

理工学部 物理学科 （矢上）

職名

助教

外部リンク
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経歴 【 表示 ／ 非表示 】

  • 2005年04月
    -
    2008年03月

    東京大学, 天文学教育研究センター

  • 2008年04月
    -
    2008年09月

    国立天文台, 野辺山宇宙電波観測所, PD

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研究分野 【 表示 ／ 非表示 】

  • 自然科学一般 / 天文学

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  • 電波天文学

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研究テーマ 【 表示 ／ 非表示 】

  • 銀河系中心、大質量星形成、近傍銀河, 

    2005年04月
    -
    継続中

    　研究概要を見る

    Galactic Center, Massive Star Formation, Nearby Galaxies

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論文 【 表示 ／ 非表示 】

  • Reconstructing the shock history in the CMZ of NGC 253 with ALCHEMI

    Huang, K. -Y. ; Viti, S. ; Holdship, J. ; Mangum, J. G. ; Martín, S. ; Harada, N. ; Muller, S. ; Sakamoto, K. ; Tanaka, K. ; Yoshimura, Y. ; Herrero-Illana, R. ; Meier, D. S. ; Behrens, E. ; van der Werf, P. P. ; Henkel, C. ; García-Burillo, S. ; Rivilla, V. M. ; Emig, K. L. ; Colzi, L. search by orcid ; Humire, P. K. ; ...

    2023年03月

    研究論文（学術雑誌）, 共著, 査読有り

  • Energizing Star Formation: The Cosmic-Ray Ionization Rate in NGC 253 Derived from ALCHEMI Measurements of H<inf>3</inf>O<sup>+</sup>and SO

    Holdship J., Mangum J.G., Viti S., Behrens E., Harada N., Martín S., Sakamoto K., Muller S., Tanaka K., Nakanishi K., Herrero-Illana R., Yoshimura Y., Aladro R., Colzi L., Emig K.L., Henkel C., Nishimura Y., Rivilla V.M., Van Der Werf P.P.

    Astrophysical Journal （Astrophysical Journal)  931 （ 2 ）  2022年06月

    研究論文（学術雑誌）, 査読有り,  ISSN  0004637X

    　概要を見る

    The cosmic-ray ionization rate (CRIR) is a key parameter in understanding the physical and chemical processes in the interstellar medium. Cosmic rays are a significant source of energy in star formation regions, impacting the physical and chemical processes that drive the formation of stars. Previous studies of the circum-molecular zone of the starburst galaxy NGC 253 have found evidence for a high CRIR value: 103-106 times the average CRIR within the Milky Way. This is a broad constraint, and one goal of this study is to determine this value with much higher precision. We exploit ALMA observations toward the central molecular zone of NGC 253 to measure the CRIR. We first demonstrate that the abundance ratio of H3O+ and SO is strongly sensitive to the CRIR. We then combine chemical and radiative transfer models with nested sampling to infer the gas properties and CRIR of several star-forming regions in NGC 253 from emission from their transitions. We find that each of the four regions modeled has a CRIR in the range (1-80) × 10-14 s-1 and that this result adequately fits the abundances of other species that are believed to be sensitive to cosmic rays, including C2H, HCO+, HOC+, and CO. From shock and photon-dominated/X-ray dominated region models, we further find that neither UV-/X-ray-driven nor shock-dominated chemistry is a viable single alternative as none of these processes can adequately fit the abundances of all of these species.

  • First extragalactic detection of a phosphorus-bearing molecule with ALCHEMI: Phosphorus nitride (PN)

    Haasler D., Rivilla V.M., Martín S., Holdship J., Viti S., Harada N., Mangum J., Sakamoto K., Muller S., Tanaka K., Yoshimura Y., Nakanishi K., Colzi L., Hunt L., Emig K.L., Aladro R., Humire P., Henkel C., Van Der Werf P.

    Astronomy and Astrophysics （Astronomy and Astrophysics)  659   158 2022年03月

    研究論文（学術雑誌）, 共著, 査読有り,  ISSN  00046361

    　概要を見る

    Context. Phosphorus (P) is a crucial element for life given its central role in several biomolecules. P-bearing molecules have been discovered in different regions of the Milky Way, but not yet towards an extragalactic environment. Aims. We searched for P-bearing molecules outside the Milky Way towards the nearby starburst Galaxy NGC 253. Methods. Using observations from the ALMA Comprehensive High-resolution Extragalactic Molecular Inventory (ALCHEMI) project, we used the MAdrid Data CUBe Analysis package to model the emission of P-bearing molecules assuming local thermodynamic equilibrium (LTE) conditions. We also performed a non-LTE analysis using SpectralRadex. Results. We report the detection of a P-bearing molecule, phosphorus nitride (PN), for the first time in an extragalactic environment, towards two giant molecular clouds (GMCs) of NGC 253. The LTE analysis yields total PN beam-averaged column densities N = (1.20 ± 0.09) - 1013 cm-2 and N = (6.5 ± 1.6) - 1012 cm-2, which translate into abundances with respect to H2 of = (8.0 ± 1.0) - 10-12 and = (4.4 ± 1.2) - 10-12. We derived a low excitation temperature of Tex = (4.4 ± 1.3) K towards the GMC with the brightest PN emission, which indicates that PN is sub-thermally excited. The non-LTE analysis results in column densities consistent with the LTE values. We also searched for other P-bearing molecules (PO, PH3, CP, and CCP), and upper limits were derived. The derived PO/PN ratios are < 1.3 and < 1.7. The abundance ratio between PN and the shock-tracer SiO derived towards NGC 253 follows the same trend previously found towards Galactic sources. Conclusions. Comparison of the observations with chemical models indicates that the derived molecular abundances of PN in NGC 253 can be explained by shock-driven chemistry followed by cosmic-ray-driven photochemistry.

  • Methanol masers in NGC 253 with ALCHEMI

    Humire P.K., Henkel C., Hernández-Gómez A., Martín S., Mangum J., Harada N., Muller S., Sakamoto K., Tanaka K., Yoshimura Y., Nakanishi K., Mühle S., Herrero-Illana R., Meier D.S., Caux E., Aladro R., Mauersberger R., Viti S., Colzi L., Rivilla V.M., Gorski M., Menten K.M., Huang K.Y., Aalto S., Van Der Werf P.P., Emig K.L.

    Astronomy and Astrophysics （Astronomy and Astrophysics)  663 2022年

    研究論文（学術雑誌）, 査読有り,  ISSN  00046361

    　概要を見る

    Context. Methanol masers of Class I (collisionally pumped) and Class II (radiatively pumped) have been studied in great detail in our Galaxy in a variety of astrophysical environments such as shocks and star-forming regions and are they are helpful to analyze the properties of the dense interstellar medium. However, the study of methanol masers in external galaxies is still in its infancy. Aims. Our main goal is to search for methanol masers in the central molecular zone (CMZ; inner 500 pc) of the nearby starburst galaxy NGC253. Methods. Covering a frequency range between 84 and 373 GHz (λ = 3.6-0.8 mm) at high angular (1."6 ∼ 27 pc) and spectral (∼8-9 km s-1) resolution with ALCHEMI (ALMA Comprehensive High-resolution Extragalactic Molecular Inventory), we have probed dierent regions across the CMZ of NGC253. In order to look for methanol maser candidates, we employed the rotation diagram method and a set of radiative transfer models. Results.We detect for the first time masers above 84 GHz in NGC253, covering an ample portion of the J-1 (J-1)0-E line series (at 84, 132, 229, and 278 GHz) and the J0 (J-1)1 A series (at 95, 146, and 198 GHz). This confirms the presence of the Class I maser line at 84 GHz, which was already reported, but now being detected in more than one location. For the J-1 (J-1)0-E line series, we observe a lack of Class I maser candidates in the central star-forming disk. Conclusions. The physical conditions for maser excitation in the J-1 (J-1)0-E line series can be weak shocks and cloud-cloud collisions as suggested by shock tracers (SiO and HNCO) in bi-symmetric shock regions located in the outskirts of the CMZ. On the other hand, the presence of photodissociation regions due to a high star-formation rate would be needed to explain the lack of Class I masers in the very central regions.

  • Energizing Star Formation: The Cosmic Ray Ionization Rate in NGC 253 Derived From ALCHEMI Measurements of H$_3$O$^+$ and SO

    Holdship, Jonathan ; Mangum, Jeffrey G. ; Viti, Serena ; Behrens, Erica ; Harada, Nanase ; Martín, Sergio ; Sakamoto, Kazushi ; Muller, Sebastien ; Tanaka, Kunihiko ; Nakanishi, Kouichiro ; Herrero-Illana, Rubén ; Yoshimura, Yuki ; Aladro, Rebeca ; Colzi, Laura ; Emig, Kimberly L. ; Henkel, Christian ; Nishimura, Yuri ; Rivilla, Víctor M. ; van der Werf, Paul P.

    The Astrophysical Journal 2022年

    研究論文（学術雑誌）, 共著, 査読有り

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研究発表 【 表示 ／ 非表示 】

  • Star Formation Conditions In the Milky Way’s Galactic Central Molecular Zone

    田中 邦彦

    Star Formation in Different Environments 2017, 

    2017年08月

  • Search for the CO-dark Mass in the Central Molecular Zone by using the ASTE 10-m Telescope

    田中 邦彦

    IAUS 322: The Multi-Messenger Astrophysics of the Galactic Centre, 

    2016年07月
    , 

    口頭発表（一般）

  • CO-0.30-0.07: A Candidate Site of Collision-induced Massive Star Formation in the Milky Way's Central Molecular Zon

    田中 邦彦

    The 6th Zermatt ISM Symposium",, 

    2015年09月
    , 

    口頭発表（一般）

  • Giant Molecular Clouds with High Abundance of Atomic Carbon and Cyano Radical in the Milky Way's Central Molecular Zone

    田中 邦彦

    IAU General Assembly, Meeting #29 (Honolulu, HA, USA) , 

    2015年08月
    , 

    ポスター発表, International Astronomical Union

  • The ASTE Galactic Center Survey in the 350 and 500 GHz Bands

    田中 邦彦

    New Trends in Radio Astronomy in the ALMA Era / the 30th Anniversary of Nobeyama Radio Observatory (Hakone, Kanagawa, Japan) , 

    2012年12月
    , 

    口頭発表（一般）

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競争的研究費の研究課題 【 表示 ／ 非表示 】

  • 銀河系中心領域での局所的な爆発的星形成現象

    2016年04月
    -
    2019年03月

    日本学術振興会, 科学研究費補助金(文部科学省・日本学術振興会）, 田中邦彦, 補助金,  研究代表者

  • ミリ波－サブミリ波観測で探る銀河系中心活動性

    2014年04月
    -
    2016年03月

    日本学術振興会, 科学研究費補助金(文部科学省・日本学術振興会）, 補助金,  研究代表者

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Works 【 表示 ／ 非表示 】

  • 夏の星空から始める天文学：銀河系中心の不思議な天体たち

    田中邦彦

    朝日カルチャーセンター, 

    2013年08月
    , 

    その他

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担当授業科目 【 表示 ／ 非表示 】

  • 物理学セミナー第２

    2023年度

  • 物理学実験第２

    2023年度

  • 物理学実験第１

    2023年度

  • 物理学Ｂ

    2023年度

  • 自然科学実験

    2023年度

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所属学協会 【 表示 ／ 非表示 】

  • 日本天文学会

    　
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