中村 理 (ナカムラ オサム)

写真a

所属

政治経済学術院 政治経済学部

職名

准教授

ホームページ

http://saros.web.fc2.com/

兼担 【 表示 / 非表示

  • 附属機関・学校   グローバルエデュケーションセンター

  • 政治経済学術院   大学院政治学研究科

  • 理工学術院   大学院先進理工学研究科

学歴 【 表示 / 非表示

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    -
    2001年

    東京大学   理学系研究科   天文学  

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    2001年

    東京大学   理学系研究科   天文学  

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    1993年

    京都大学   理学部   物理系  

学位 【 表示 / 非表示

  • 東京大学   博士(理学)

  • 東京大学   修士

経歴 【 表示 / 非表示

  • 2011年04月
    -
    2014年03月

    東京家政学院大学非常勤講師

  • 2002年04月
    -
    2012年03月

    東京都市大学(旧武蔵工大)教育研究センター非常勤講師

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    早稲田大学政治学研究科客員研究助手(専任扱い)

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    早稲田大学政治学研究科客員研究助手(専任扱い)

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    早稲田大学政治経済学術院助教

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所属学協会 【 表示 / 非表示

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    日本天文学会

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    日本科学教育学会

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    科学技術社会論学会

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    日本マス・コミュニケーション学会

 

研究分野 【 表示 / 非表示

  • 天文学

  • 科学教育

  • 科学社会学、科学技術史

研究キーワード 【 表示 / 非表示

  • 天文学

  • 科学コミュニケーション

  • 科学技術社会論

  • ジャーナリズム

論文 【 表示 / 非表示

  • The Tully-Fisher relation of intermediate redshift field and cluster galaxies from Subaru spectroscopy

    O Nakamura, A Aragon-Salamanca, B Milvang-Jensen, N Arimoto, C Ikuta, SP Bamford

    MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY   366 ( 1 ) 144 - 162  2006年02月  [査読有り]

     概要を見る

    We have carried out spectroscopic observations in four cluster fields using Subaru's FOCAS multislit spectrograph and obtained spectra for 103 bright disc field and cluster galaxies at 0.06 <= z <= 1.20. 77 of these show emission lines, and 33 provide reasonably secure determinations of the galaxies' rotation velocity. The rotation velocities, luminosities, colours and emission-line properties of these galaxies are used to study the possible effects of the cluster environment on the star formation history of the galaxies. Comparing the Tully-Fisher relations of cluster and field galaxies at similar redshifts we find no measurable difference in rest-frame B-band luminosity at a given rotation velocity (the formal difference is 0.18 +/- 0.33). The colours of the cluster emission line galaxies are only marginally redder in rest-frame B-V(by 0.06 +/- 0.04 mag) than the field galaxies in our sample. Taken at face value, these results seem to indicate that bright star-forming cluster spirals are similar to their field counterparts in their star formation properties. However, we find that the fraction of disc galaxies with absorption-line spectra (i.e. with no current star formation) is larger in clusters than in the field by a factor of similar to 3-5. This suggests that the cluster environment has the overall effect of switching off star formation in (at least) some spiral galaxies. To interpret these observational results, we carry out simulations of the possible effects of the cluster environment on the star formation history of disc galaxies and thus their photometric and spectroscopic properties. This allows us to create mock samples of unperturbed 'field' galaxies [with approximately constant star formation rates (SFRs)] and perturbed 'cluster' galaxies with different star formation histories, including star formation truncation, with or without an associated starburst. We show that, if we select only bright galaxies with current star formation (i.e. with emission lines strong enough for rotation-curve measurements), the average colours and luminosities of the 'cluster' galaxies may not be very different from those of galaxies in the 'field' sample, even though their star formation histories may be significantly different. However, the fraction of emission and absorption-line galaxies would change significantly. We also use these simulations to estimate the size of field and cluster galaxy samples that would allow us to differentiate the different star formation scenarios considered. Finally, we find that the rest-frame absolute B-band magnitude of the field galaxies in our sample shows an evolution of -1.30 +/- 1.04 mag per unit redshift at fixed rotation velocity. This indicates that the average SFR of bright disc galaxies evolves more slowly than the universal SFR as determined from ultraviolet, H alpha, far-infrared and radio studies. This suggests the evolution of the universal SFR density is not dominated by bright star-forming disc galaxies, in agreement with previous studies.

    DOI

  • The Hα Luminosity Function of Morphologically Classified Galaxies in the Sloan Digital Sky Survey

    Nakamura et

    The Astronomical Journal   127 ( 5 ) 2511 - 2521  2004年05月  [査読有り]

     概要を見る

    We present a study of the Halpha line emission from a sample of 1482 optically selected, morphologically classified bright galaxies (median redshift of 0.05) derived from the Sloan Digital Sky Survey. The luminosity function is calculated for each morphological class and for the total sample. The luminosity function fitted with the Schechter form gives a slope alpha = -1.43 +/- 0.10 for the total sample, and the Halpha luminosity density is 10(-0.07)(39.31 +/- 0.04)(+0.10) h ergs s(-1) Mpc(-3), where the first error is statistical and the second is systematic. This value is consistent with that derived by Gallego et al. in 1995, but this agreement is caused by a fortuitous cancellation of their neglect of stellar absorption that affects the estimate of extinction corrections and a significant sample incompleteness of emission-line galaxies. The fraction of Halpha emitters monotonically increases from early ( a few percent for elliptical galaxies) to late types (100% for irregular galaxies), whereas strong emitters exist in all classes of morphological types. We find that 83% of the luminosity density comes from spiral galaxies, 5% from irregular galaxies, and 9% from early-type galaxies; a small number of morphologically disturbed galaxies contribute by 3%.

  • The luminosity function of morphologically classified galaxies in the Sloan Digital Sky Survey

    O Nakamura, M Fukugita, N Yasuda, J Loveday, J Brinkmann, DP Schneider, K Shimasaku, M SubbaRao

    ASTRONOMICAL JOURNAL   125 ( 4 ) 1682 - 1688  2003年04月  [査読有り]

     概要を見る

    The morphological dependence of the luminosity function is studied, using a sample containing approximately 1500 bright galaxies classified into Hubble types by visual inspection, for a homogeneous sample obtained from the Sloan Digital Sky Survey northern equatorial stripes. Early-type galaxies are shown to have a characteristic magnitude 0.45 mag brighter than that of spiral galaxies in the r* band, consistent with the "universal characteristic luminosity'' in the B band. The shape of the luminosity function differs rather little among different morphological types: we do not see any symptoms of the sharp decline in the faint end of the luminosity function for early-type galaxies at least 2 mag fainter than the characteristic magnitude, although the faint-end behavior shows a slight decline (alpha less than or similar to -1) compared with the total sample. We also show that the rather. at faint-end slope for early-type galaxies is not due to an increasing mixture of dwarf galaxies, which have softer cores. This means that there are numerous faint early-type galaxies with highly concentrated cores.

共同研究・競争的資金等の研究課題 【 表示 / 非表示

  • 福島第一原発事故における日本政府記者会見と各国の新聞報道の比較分析

    研究期間:

    2014年04月
    -
    2017年03月
     

     概要を見る

    東日本大震災に伴う福島第一原発事故の初期段階について「事故の実態」「日本政府記者会見(東京電力を含む)」「全国紙の報道」という三者の関係性を分析した。「炉心溶融」に絞り、量的かつ質的に分析したところ、全体として、炉心溶融の実態を政府記者会見が過小に評価し、その記者会見を踏襲した形で報道される傾向がみられた。また、隣国である中国の新聞は当時、記事の情報源として日本のメディア報道を採用していた。本研究では日本政府記者会見をテキスト化しFUKUSHIMA STUDYのサイトで公開した。この会見テキストを用い、記者会見における記者の積極性や記者会見と新聞報道の連動性について、より詳細な分析を実施した

 

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