2024/04/22 更新

写真a

ナカムラ オサム
中村 理
所属
政治経済学術院 政治経済学部
職名
准教授
学位
修士 ( 1997年03月 東京大学 )
博士(理学) ( 2001年03月 東京大学 )
メールアドレス
メールアドレス
ホームページ

経歴

  • 2012年04月
    -
    継続中

    早稲田大学政治経済学術院准教授

  • 2011年04月
    -
    2014年03月

    東京家政学院大学非常勤講師

  • 2010年04月
    -
    2012年03月

    早稲田大学政治経済学術院助教

  • 2006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

  • 2007年04月
    -
    2010年03月

    早稲田大学政治学研究科客員講師(専任扱い)

  • 2005年10月
    -
    2007年03月

    早稲田大学政治学研究科客員研究助手(専任扱い)

  • 2003年09月
    -
    2005年09月

    英国PPARC研究員(ノッティンガム大学)

  • 2001年04月
    -
    2003年09月

    東京大学宇宙線研究所COE研究員

  • 2002年04月
    -
    2003年08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

▼全件表示

学歴

  • 1997年04月
    -
    2001年03月

    東京大学   理学系研究科   博士課程天文学専攻  

  • 1995年04月
    -
    1997年03月

    東京大学   理学系研究科   修士課程天文学専攻  

  • 1989年04月
    -
    1993年04月

    京都大学   理学部   物理系  

委員歴

  • 2018年12月
    -
    2024年04月

    科学技術社会論学会  『科学技術社会論研究』編集委員

  • 2018年04月
    -
    2019年03月

    Japan Association for Media, Journalism and Communication Studies  'Asian Journal of Journalism and Media Studies' 2019 Editorial Board

  • 2009年11月
    -
     

    科学技術社会論学会  第8回(2009年11月)年次研究大会実行委員会事務局長

所属学協会

研究分野

  • 社会学   ジャーナリズム / 社会学   メディア / ジェンダー   Gender / 科学社会学、科学技術史   科学技術社会論 / 科学教育   Science Education / 天文学   Astronomy

研究キーワード

  • 内容分析

  • メディア

  • ジャーナリズム

  • ジェンダー

  • 科学技術社会論

  • 科学コミュニケーション

  • 天文学

▼全件表示

 

論文

  • 読売新聞にみる殺人関連事件の被疑者・被告人――犯人視報道と実名報道の観点から

    高城玲奈, 中村理

    教養諸學研究   152   1 - 29  2024年03月  [国内誌]

    担当区分:最終著者, 責任著者

  • 「よい絵本」リストにみるジェンダー観

    河合柚佳, 中村理

    日本ジェンダー研究   26   65 - 78  2023年11月  [査読有り]  [国内誌]

    担当区分:最終著者, 責任著者

  • 2020年東京オリンピック招致にかんするテレビ報道の共振性

    井美奈子, 中村理

    教養諸學研究   151   43 - 74  2023年03月  [国内誌]

    担当区分:最終著者, 責任著者

  • 朝日新聞と読売新聞の社説における原発報道の論調とフレーム

    名和旭, 中村理

    教養諸學研究   150   113 - 151  2022年03月  [国内誌]

    担当区分:最終著者, 責任著者

  • アメリカの大学における科学ジャーナリスト・ライター養成カリキュラム

    中村理

    敎養諸學研究   141   25 - 48  2016年12月  [国内誌]

    担当区分:筆頭著者, 責任著者

  • Properties of disks and bulges of spiral and lenticular galaxies in the Sloan Digital Sky Survey

    N. Oohama, S. Okamura, M. Fukugita, N. Yasuda, O. Nakamura

    Astrophysical Journal   705 ( 1 ) 245 - 705  2009年11月  [査読有り]  [国際誌]  [国際共著]

     概要を見る

    A bulge-disk decomposition is made for 737 spiral and lenticular galaxies drawn from a Sloan Digital Sky Survey galaxy sample for which morphological types are estimated. We carry out the bulge-disk decomposition using the growth curve fitting method. It is found that bulge properties, effective radius, effective surface brightness, and also absolute magnitude, change systematically with the morphological sequence; from early to late types, the size becomes somewhat larger, and surface brightness and luminosity fainter. In contrast, disks are nearly universal, their properties remaining similar among disk galaxies irrespective of detailed morphologies from S0 to Sc. While these tendencies were often discussed in previous studies, the present study confirms them based on a large homogeneous magnitude-limited field galaxy sample with morphological types estimated. The systematic change of bulge-to-total luminosity ratio, B/T, along the morphological sequence is therefore not caused by disks but mostly by bulges. It is also shown that elliptical galaxies and bulges of spiral galaxies are unlikely to be in a single sequence. We infer the stellar mass density (in units of the critical mass density) to be Ω = 0.0021 for spheroids, i.e., elliptical galaxies plus bulges of spiral galaxies, and Ω = 0.00081 for disks.

    DOI

    Scopus

    26
    被引用数
    (Scopus)
  • A catalog of morphologically classified galaxies from the sloan digital sky survey: North equatorial region

    Masataka Fukugita, Osamu Nakamura, Sadanori Okamura, Naoki Yasuda, John C. Barentine, Jon Brinkmann, James E. Gunn, Mike Harvanek, Takashi Ichikawa, Robert H. Lupton, Donald P. Schneider, Michael A. Strauss, Donald G. York

    Astronomical Journal   134 ( 2 ) 579 - 593  2007年08月  [査読有り]  [国際誌]  [国際共著]

     概要を見る

    We present a catalog of morphologically classified bright galaxies in the north equatorial stripe (230 deg2) derived from the Third Data Release of the Sloan Digital Sky Survey (SDSS). Morphological classification is performed by visual inspection of images in the g band. The catalog contains 2253 galaxies complete to a magnitude limit of r = 16 after Galactic extinction correction, selected from 2658 objects that are judged to be extended in the photometric catalog in the same magnitude limit. A total of 1866 galaxies in our catalog have spectroscopic information. A brief statistical analysis is presented for the frequency of morphological types and mean colors in the catalog. A visual inspection of the images reveals that the rate of interacting galaxies in the local universe is approximately 1.5% in the r ≤ 16 sample. A verification is made for the photometric catalog generated by the SDSS, especially as to its brightend completeness. © 2007. The American Astronomical Society. All rights reserved.

    DOI

    Scopus

    125
    被引用数
    (Scopus)
  • Elemental abundance measurements in low-redshift damped Lyman α absorbers

    Joseph D. Meiring, Varsha P. Kulkarni, Pushpa Khare, Jill Bechtold, Donald G. York, Jun Cui, James T. Lauroesch, Arlin P.S. Crotts, Osamu Nakamura

    Monthly Notices of the Royal Astronomical Society   370 ( 1 ) 43 - 62  2006年07月  [査読有り]  [国際誌]  [国際共著]

     概要を見る

    We present elemental abundance measurements for nine damped Lyman α (Lyα) systems (DLAs) and one sub-DLA at 0.1 ≤ z ≤ 1.5 from recent observations with the Multiple Mirror Telescope (MMT). Most of these absorbers are found to be metal poor, while two are found to have ≈30-50 per cent solar metallicities. Combining our data with other data from the literature, we find that the systems with higher [Zn/H] also have stronger depletion as measured by [Cr/Zn] and [Fe/Zn]. The relationship between the metallicity and Hi column density is also investigated. Together with our previous MMT survey, we have discovered two of the four known absorbers at z < 1.5 that lie above (although near) the 'obscuration threshold'. This appears to be a result of selecting absorbers with strong metal lines in our sample. It would be interesting to find other similar systems by observing a larger sample and study how much such systems contribute to the cosmic budget of metals. Finally, an analysis of the NHI-weighted mean metallicity versus redshift for our sample combined with data from the literature supports previous conclusions that the NHI-weighted mean global DLA metallicity rises slowly at best and falls short of solar levels by a factor of >4 even at z = 0. © 2006 RAS.

    DOI

    Scopus

    43
    被引用数
    (Scopus)
  • Star formation rates and chemical abundances of emission-line galaxies in intermediate-redshift clusters

    M. Mouhcine, S. P. Bamford, A. Aragón-Salamanca, O. Nakamura, B. Milvang-Jensen

    Monthly Notices of the Royal Astronomical Society   368 ( 4 ) 1871 - 1879  2006年06月  [査読有り]  [国際誌]  [国際共著]

     概要を見る

    We examine the evolutionary status of luminous, star-forming galaxies in intermediate-redshift clusters by considering their star formation rates (SFRs) and the chemical and ionization properties of their interstellar emitting gas. Our sample consists of 17 massive, star-forming, mostly disc galaxies with , in clusters with redshifts in the range , with a median of . We compare these galaxies with the identically selected and analysed intermediate-redshift field sample of Mouhcine et al., and with local galaxies from the Nearby Field Galaxy Survey of Jansen et al. From our optical spectra, we measure the equivalent widths of and [O iii]λ5007 emission lines to determine diagnostic line ratios, oxygen abundances and extinction-corrected SFRs. The star-forming galaxies in intermediate-redshift clusters display emission-line equivalent widths which are, on average, significantly smaller than measured for field galaxies at comparable redshifts. However, a contrasting fraction of our cluster galaxies have equivalent widths similar to the highest observed in the field. This tentatively suggests a bimodality in the SFRs per unit luminosity for galaxies in distant clusters. We find no evidence for further bimodalities, or differences between our cluster and field samples, when examining additional diagnostics and the oxygen abundances of our galaxies. This maybe because no such differences exist, perhaps because the cluster galaxies which still display signs of star formation have recently arrived from the field. In order to examine this topic with more certainty, and to further investigate the way in which any disparity varies as a function of cluster properties, larger spectroscopic samples are needed. © 2006 RAS.

    DOI

    Scopus

    7
    被引用数
    (Scopus)
  • The metallicities of luminous, massive field galaxies at intermediate redshifts

    M. Mouhcine, S. P. Bamford, A. Aragón-Salamanca, O. Nakamura, B. Milvang-Jensen

    Monthly Notices of the Royal Astronomical Society   369 ( 2 ) 891 - 908  2006年06月  [査読有り]  [国際誌]  [国際共著]

     概要を見る

    We derive oxygen abundances for a sample of 40 luminous (MB ≲ -19), star-forming, mostly disc, field galaxies with redshifts in the range 0.2 ≲ z ≲ 0.8, with a median of 〈z〉 = 0.45. Oxygen abundances, relative to hydrogen, of the interstellar emitting gas are estimated by means of the empirically calibrated strong emission-line ratio technique. The derived 12 + log (O/H) values range from 8.4 to 9.0, with a median of 8.7. Twenty of these galaxies have securely measured rotation velocities, in the range 50-244 km s-1. The measured emission-line equivalent widths and diagnostic ratios for the intermediate redshift galaxies cover similar ranges to those observed across a large sample of local galaxies. The estimated oxygen abundances for our luminous star-forming intermediate redshift galaxies cover the same range as their local counterparts. However, at a given galaxy luminosity, many of our galaxies have significantly lower oxygen abundances, i.e. 12 + log (O/H) ∼8.6, than local galaxies with similar luminosities. Interestingly, these luminous, massive, intermediate redshift, star-forming galaxies with low oxygen abundances exhibit physical conditions, i.e. emission-line equivalent width and ionization state, very similar to those of local faint and metal-poor star-forming galaxies. The oxygen abundance of the interstellar gas does not seem to correlate with the maximum rotation velocity or the emission scalelength of the parent galaxy. This suggests that there is diversity in the intrinsic properties of the massive field galaxy population at intermediate redshifts. The distribution of the colour excess, derived from the ratio of extinction-uncorrected Hβ and [O II]λ3727 star formation rate indicators, covers a similar range to that observed locally, but exhibits a lower mean than is observed for local optically selected star-forming galaxies. Luminous field galaxies at intermediate redshifts show similar star formation rates to their local counterparts. However, metal-poor, massive, star-forming galaxies tend to be systematically less affected by internal reddening than metal-rich, massive galaxies, which cover similar range of colour excess to local metal-rich luminous galaxies. Finally, the correlation between oxygen abundance and colour excess for intermediate redshift galaxies is found to be similar to what is observed locally. This result indicates that the dust content of galaxies is more regulated by their chemical evolution rather than by galaxy luminosity. © 2006 RAS.

    DOI

    Scopus

    14
    被引用数
    (Scopus)
  • 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]  [国際誌]  [国際共著]

    担当区分:筆頭著者, 責任著者

     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 &lt;= z &lt;= 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

  • Morphological classification of galaxies using photometric parameters: The concentration index versus the coarseness parameter

    Chisato Yamauchi, Shin Ichi Ichikawa, Mamoru Doi, Naoki Yasuda, Masafumi Yagi, Masataka Fukugita, Sadanori Okamura, Osamu Nakamura, Maki Sekiguchi, Tomotsugu Goto

    Astronomical Journal   130 ( 4 ) 1545 - 1557  2005年10月  [査読有り]  [国際誌]  [国際共著]

     概要を見る

    We devise improved photometric parameters for the morphological classification of galaxies using a bright sample from the First Data Release of the Sloan Digital Sky Survey. In addition to using an elliptical aperture concentration index for classification, we introduce a new texture parameter, coarseness, which quantifies deviations from smooth galaxy isophotes. The elliptical aperture concentration index produces morphological classifications that are in appreciably better agreement with visual classifications than those based on circular apertures. With the addition of the coarseness parameter, the success rate of classifying galaxies into early and late types increases to ≃88% with respect to the reference visual classification. A reasonably high success rate (≃68%) is also attained in classifying galaxies into three types, early-type galaxies (E+S0) and early-type (Sa+Sb) and late-type (Sc+Sdm+Im) spiral galaxies. © 2005. The American Astronomical Society. All rights reserved.

    DOI

    Scopus

    50
    被引用数
    (Scopus)
  • The luminosity and color dependence of the galaxy correlation function

    Idit Zehavi, Zheng Zheng, David H. Weinberg, Joshua A. Frieman, Andreas A. Berlind, Michael R. Blanton, Roman Scoccimarro, Ravi K. Sheth, Michael A. Strauss, Issha Kayo, Yasushi Suto, Masataka Fukugita, Osamu Nakamura, Neta A. Bahcall, Jon Brinkmann, James E. Gunn, Greg S. Hennessy, Željko Ivezić, Gillian R. Knapp, Jon Loveday, Avery Meiksin, David J. Schlegel, Donald P. Schneider, Istvan Szapudi, Max Tegmark, Michael S. Vogeley, Donald G. York

    Astrophysical Journal   630 ( 1 I ) 1 - 27  2005年09月  [査読有り]  [国際誌]  [国際共著]

     概要を見る

    We study the luminosity and color dependence of the galaxy two-point correlation function in the Sloan Digital Sky Survey, starting from a sample of ∼200,000 galaxies over 2500 deg2. We concentrate our analysis on volume-limited subsamples of specified luminosity ranges, for which we measure the projected correlation function wp(rp), which is directly related to the real-space correlation function ξ(r). The amplitude of wp(rp) rises continuously with luminosity from M r ≈ -17.5 to Mr ≈ -22.5, with the most rapid increase occurring above the characteristic luminosity L* (Mr ≈ -20.5). Over the scales 0.1 h-1 Mpc < rp < 10 h-1 Mpc, the measurements for samples with Mr > -22 can be approximated, imperfectly, by power-law three-dimensional correlation functions ξ(r) = (r/r0)-γ with γ ≈ 1.8 and r0(L*) ≈ 5.0 h-1 Mpc. The brightest subsample, -23 < Mr < -22, has a significantly steeper ξ(r). When we divide samples by color, redder galaxies exhibit a higher amplitude and steeper correlation function at all luminosities. The correlation amplitude of blue galaxies increases continuously with luminosity, but the luminosity dependence for red galaxies is less regular, with bright red galaxies exhibiting the strongest clustering at large scales and faint red galaxies exhibiting the strongest clustering at small scales. We interpret these results using halo occupation distribution (HOD) models assuming concordance cosmological parameters. For most samples, an HOD model with two adjustable parameters fits the wp(rp) data better than a power law, explaining inflections at rp ∼ 1-3 h-1 Mpc as the transition between the one-halo and two-halo regimes of ξ(r). The implied minimum mass for a halo hosting a central galaxy more luminous than L grows steadily, with Mmin ∝ L at low luminosities and a steeper dependence above L*. The mass at which a halo has, on average, one satellite galaxy brighter than L is M1 ≈ 23Mmin(L), at all luminosities. These results imply a conditional luminosity function (at fixed halo mass) in which central galaxies lie far above a Schechter function extrapolation of the satellite population. The HOD model fits nicely explain the color dependence of wp(rp) and the cross correlation between red and blue galaxies. For galaxies with Mr < -21, halos slightly above M min have blue central galaxies, while more massive halos have red central galaxies and predominantly red satellite populations. The fraction of blue central galaxies increases steadily with decreasing luminosity and host halo mass. The strong clustering of faint red galaxies follows from the fact that nearly all of them are satellite systems in high-mass halos. The HOD fitting results are in good qualitative agreement with the predictions of numerical and semianalytic models of galaxy formation. © 2005. The American Astronomical Society. All rights reserved.

    DOI

    Scopus

    627
    被引用数
    (Scopus)
  • Metals and dust in intermediate-redshift damped Lyα galaxies

    Pushpa Khare, Varsha P. Kulkarni, James T. Lauroesch, Donald G. York, Arlin P.S. Crotts, Osamu Nakamura

    Astrophysical Journal   616 ( 1 I ) 86 - 109  2004年11月  [査読有り]  [国際誌]  [国際共著]

     概要を見る

    We report on spectroscopic observations with the Multiple Mirror Telescope for 11 damped Lyα absorbers (DLAs) or strong DLA candidates at 0.1 < z < 1.5, including several absorbers discovered in the Sloan Digital Sky Survey. In particular, we have measured absorption lines of Zn II, Cr II, Ni II, Fe II, Mn II, Ti II, Ca II, and Si II. These measurements have doubled the sample of Zn and Cr measurements at z < 1. The average relative abundance patterns in these objects are very similar to those found for high-redshift DLAs reported in the literature. Our observations suggest that the dust content, as determined by [Cr/Zn], does not show much change with redshift. We also examine the sample for correlation of [Cr/Zn] with estimates of the quasar reddening. Our data suggest that the global mean metallicity of DLAs, as measured by the gas-phase abundance of Zn, at best shows a weak evolution with redshift over the range 0.4 < z < 3.9.

    DOI

    Scopus

    68
    被引用数
    (Scopus)
  • The Hα luminosity function of morphologically classified galaxies in the sloan digital sky survey

    Osamu Nakamura, Masataka Fukugita, Jon Brinkmann, Donald P. Schneider

    Astronomical Journal   127 ( 5 1781 ) 2511 - 2521  2004年05月  [査読有り]  [国際誌]  [国際共著]

    担当区分:筆頭著者

     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%.

    DOI

    Scopus

    53
    被引用数
    (Scopus)
  • The search for galaxy clustering around a quasar pair at z = 4.25 found in the sloan digital sky survey

    Masataka Fukugita, Osamu Nakamura, Donald P. Schneider, Mamoru Doi, Nobunari Kashikawa

    Astrophysical Journal   603 ( 2 II )  2004年03月  [査読有り]  [国際誌]  [国際共著]

     概要を見る

    We present an investigation of the environment (≈600 kpc radius) of a pair of luminous z = 4.25 quasars, SDSS J1439-0034A and B, separated by 33″. An analysis of high-quality Subaru spectra of the quasars suggests that this configuration is indeed a physical pair and not a gravitational lens; the redshifts are slightly different (although marginally consistent with being the same), and the two spectra have strikingly different features. We search for bright galaxies (L ≳ 0.4L*) having similar redshifts using the V dropout technique and semi-narrowband imaging looking for strong Lyα emission. We find no enhancement in the galaxy density around the quasar pair; its environment differs very little from a general field, with the upper limit of the density enhancement being about 3.5 at a 90% confidence. We infer that bright quasars happened to appear in two normal galaxies in a general field.

    DOI

    Scopus

    12
    被引用数
    (Scopus)
  • Galaxy types in the Sloan Digital Sky survey using supervised artificial neural networks

    N. M. Ball, J. Loveday, M. Fukugita, O. Nakamura, S. Okamura, J. Brinkmann, R. J. Brunner

    Monthly Notices of the Royal Astronomical Society   348 ( 3 ) 1038 - 1046  2004年03月  [査読有り]  [国際誌]  [国際共著]

     概要を見る

    Supervised artificial neural networks are used to predict useful properties of galaxies in the Sloan Digital Sky Survey, in this instance morphological classifications, spectral types and redshifts. By giving the trained networks unseen data, it is found that correlations between predicted and actual properties are around 0.9 with rms errors of order ten per cent. Thus, given a representative training set, these properties may be reliably estimated for galaxies in the survey for which there are no spectra and without human intervention.

    DOI

    Scopus

    118
    被引用数
    (Scopus)
  • Actively star-forming elliptical galaxies at low redshifts in the Sloan Digital Sky Survey

    Masataka Fukugita, Osamu Nakamura, Edwin L. Turner, Joe Helmboldt, R. C. Nichol

    Astrophysical Journal   601 ( 2 II )  2004年02月  [査読有り]  [国際誌]  [国際共著]

     概要を見る

    We report the discovery of actively star-forming elliptical galaxies in a morphologically classified sample of bright galaxies at a low redshift obtained from the Sloan Digital Sky Survey. The emission lines of these galaxies do not show the characteristics of active galactic nuclei, and thus their strong Hα emission is ascribed to star formation with a rate nearly as high as that seen in typical late spiral galaxies. This is taken as evidence against the traditional view that all elliptical galaxies formed early and now evolve only passively. The frequency of such star-forming elliptical galaxies is a few tenths of a percent in the sample but increases to 3% if we include active S0 galaxies. We can identify these galaxies as probable progenitors of so-called E+A galaxies that show the strong Balmer absorption feature of A stars superimposed on an old star population. The approximate match of the abundance of active elliptical plus S0 galaxies to that of E+A galaxies indicates that the duration of such late star formation episodes is of the order of ≲1 Gyr. If we interpret these galaxies as new additions to the early-type galaxy population, and if we assume a power law for their number evolution, the abundance of early-type galaxies at z = 1 is about 30% less than that at z = 0.

    DOI

    Scopus

    63
    被引用数
    (Scopus)
  • The luminosity function of morphologically classified galaxies in the Sloan Digital Sky Survey

    Osamu Nakamura, Masataka Fukugita, Naoki Yasuda, Jon Loveday, Jon Brinkmann, Donald P. Schneider, Kazuhiro Shimasaku, Mark SubbaRao

    Astronomical Journal   125 ( 4 1768 ) 1682 - 1688  2003年04月  [査読有り]  [国際誌]  [国際共著]

    担当区分:筆頭著者

     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.

    DOI

    Scopus

    191
    被引用数
    (Scopus)
  • Average spectra of massive galaxies in the Sloan Digital Sky Survey

    Daniel J. Eisenstein, David W. Hogg, Masataka Fukugita, Osamu Nakamura, Mariangela Bernardi, Douglas P. Finkbeiner, David J. Schlegel, J. Brinkmann, Andrew J. Connolly, István Csabai, James E. Gunn, Željko Ivezić, Don Q. Lamb, Jon Loveday, Jeffrey A. Munn, Robert C. Nicol, Donald P. Schneider, Michael A. Strauss, Alex Szalay, Don G. York

    Astrophysical Journal   585 ( 2 I ) 694 - 713  2003年03月  [査読有り]  [国際誌]  [国際共著]

     概要を見る

    We combine Sloan Digital Sky Survey spectra of 22,000 luminous, red, bulge-dominated galaxies to get high signal-to-noise ratio average spectra in the rest-frame optical and ultraviolet (2600-7000 A). The average spectra of these massive, quiescent galaxies are early type with weak emission lines and with absorption lines indicating an apparent excess of α-elements over solar abundance ratios. We make average spectra of subsamples selected by luminosity, environment, and redshift. The average spectra are remarkable in their similarity. What variations do exist in the average spectra as a function of luminosity and environment are found to form a nearly one-parameter family in spectrum space. We present a high signal-to-noise ratio spectrum of the variation. We measure the properties of the variation with a modified version of the Lick index system and compare to model spectra from stellar population syntheses. The variation may be a combination of age and chemical abundance differences, but the conservative conclusion is that the quality of the data considerably exceeds the current state of the models.

    DOI

    Scopus

    88
    被引用数
    (Scopus)
  • Sloan Digital Sky Survey: Early Data Release

    Stoughton C., et al. (Including Nakamura O.)

    Astronomical Journal   123   485 - 548  2002年01月  [査読有り]  [国際誌]  [国際共著]

  • On the origin of the color-magnitude relation in the Virgo Cluster

    Alexandre Vazdekis, Harald Kuntschner, Roger L. Davies, Nobuo Arimoto, Osamu Nakamura, Reynier Peletier

    Astrophysical Journal   551 ( 2 PART 2 ) 127 - 130  2001年04月  [査読有り]  [国際誌]  [国際共著]

     概要を見る

    We explore the origin of the color-magnitude relation (CMR) of early-type galaxies in the Virgo Cluster using spectra of very high signal-to-noise ratio for six elliptical galaxies selected along the CMR. The data are analyzed using a new evolutionary stellar population synthesis model to generate galaxy spectra at the resolution given by their velocity dispersions. In particular, we use a new age indicator that is virtually free of the effects of metallicity. We find that the luminosity-weighted mean ages of Virgo ellipticals are greater than ∼8 Gyr and show no clear trend with galaxy luminosity. We also find a positive correlation of metallicity with luminosity, color, and velocity dispersion. We conclude that the CMR is driven primarily by a luminosity-metallicity correlation. However, not all elements increase equally with the total metallicity, and we speculate that the CMR may be driven by both a total metallicity increase and a systematic departure from solar abundance ratios of some elements along the CMR. A full understanding of the role played by the total metallicity, abundance ratios, and age in generating the CMR requires the analysis of spectra of very high quality, such as those reported here, for a larger number of galaxies in Virgo and other clusters.

    DOI

    Scopus

    69
    被引用数
    (Scopus)

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書籍等出版物

  • 最新天文百科 ―宇宙・惑星・生命をつなぐサイエンス―

    M. A. Seeds, D. E. Backman, 監訳 有本 信雄, 翻訳 中村 理, 高木 俊暢, 松浦 美香子, 小野寺 仁人( 担当: 共訳)

    丸善  2010年10月 ISBN: 4621082787

    ASIN

共同研究・競争的資金等の研究課題

  • 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

    日本学術振興会  科学研究費助成事業

    研究期間:

    2014年04月
    -
    2018年03月
     

    瀬川 至朗, 中村 理

     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。

  • 原子力の開発と利用にかんする新聞社説の計量テキスト分析

    櫻田會  政治研究助成

    研究期間:

    2014年04月
    -
    2015年03月
     

    中村理

  • 米国の科学コミュニケータ系人材養成プログラムのカリキュラムに基づく、科学コミュニケータの役割と能力の多様性の分析

    日本科学協会  笹川科学研究助成

    研究期間:

    2008年04月
    -
    2009年03月
     

    中村理

  • 銀河系中心部球状星団の分光学的年齢の解明

    天文学振興財団  研究助成

    研究期間:

    2001年05月
    -
     
     

    中村理

  • 銀河系球状星団の分光学的年齢の解明

    早川幸男基金  若手海外学術研究援助基金

    研究期間:

    1999年12月
    -
     
     

    中村理

Misc

  • Astronomical news stories in the two largest Japanese newspaper Companies

    Osamu NAKAMURA

    Proceedings of the Communicating Astronomy with the Public 2018     321 - 322  2018年   [ 国際誌 ]

    記事・総説・解説・論説等(国際会議プロシーディングズ)  

  • 報道への疑問をどのように研究へつなげるか? : 内容分析の手法

    中村理

    早稻田政治經濟學雑誌   387   10 - 15  2015年03月   [ 国内誌 ]

    担当区分:筆頭著者, 責任著者

    記事・総説・解説・論説等(学術雑誌)  

  • サイエンスコミュニケーターになろう!

    中村理

    サイエンスコミュニケーション   3 ( 2 ) 24 - 25  2014年  [招待有り]   [ 国内誌 ]

    担当区分:筆頭著者, 責任著者

    書評論文,書評,文献紹介等  

  • アメリカの大学における科学技術コミュニケーター養成カリキュラムの分析

    中村理

    日本科学教育学会年会論文集   33   317 - 318  2009年08月   [ 国内誌 ]

    研究発表ペーパー・要旨(全国大会,その他学術会議)  

  • The Boom of Science Communication in Japan

    Osamu NAKAMURA

    Paper Proceedings of the 6th Asia-Pacific Symposium on Press and Scientific and Social Progress     550 - 551  2008年11月   [ 国際誌 ]

    記事・総説・解説・論説等(国際会議プロシーディングズ)  

  • The luminosity, stellar mass, and metallicity of morphologically classified galaxies in the Sloan Digital Sky Survey

    Osamu NAKAMURA

    Astronomical Society of the Pacific Conference Series   399   473 - 474  2008年10月   [ 国際誌 ]

    記事・総説・解説・論説等(国際会議プロシーディングズ)  

  • Elemental Abundance Measurements of Low Redshift Damped Lyman-alpha Galaxies

    Meiring J. D, Kulkarni V. P, Khare P, Bechtold J, Cui J, York D. G, Lauroesch J. T, Nakamura O, Crotts A. P. S

    American Astronomical Society Meeting   207  2005年12月   [ 国際誌 ]  [国際共著]

    記事・総説・解説・論説等(国際会議プロシーディングズ)  

  • Evolution of metals and dust in the universe

    Khare P, Kulkarni V. P, Lauroesch J. T, Fall, S. M, York D. G, Welty, D. E, Crotts A. P. S, Truran, J. W, Nakamura O

    Bulletin of the Astronomical Society of India   33 ( 2 ) 219  2005年06月   [ 国際誌 ]  [国際共著]

    記事・総説・解説・論説等(大学・研究所紀要)  

  • The Sloan Digital Sky Survey QSO absorption line catalogue

    Donald G. York, Daniel Vanden Berk, Gordon T. Richards, Arlin P.S. Crotts, Pushpa Khare, James Lauroesch, Martin Lemoine, Scott Burles, Mariangela Bernardi, Francisco J. Castander, Josh Frieman, Jon Loveday, Avery Meiksin, Robert Nichol, David Schlegel, Donald P. Schneider, Mark Subbarao, Chris Stoughton, Alex Szalay, Brian Yanny, Yusra Alsayyad, Abhishek Kumar, Britt Lundgren, Natela Shanidze, Johnny Vanlandingham, Matthew Wood, Britt Baugher, Jon Brinkmann, Robert Brunner, Masaaka Fukugita, Patrick B. Hall, Timothy M. Heckman, Lewis M. Hobbs, Craig J. Hogan, Lam Hui, Edward B. Jenkins, Daniel Kunstz, Brice Menard, Osamu Nakamura, Jean M. Quashnock, Michael Stein, Aniruddha R. Thakar, David Turnshek, Daniel E. Welty

    Proceedings of the International Astronomical Union   1 ( C199 ) 58 - 64  2005年   [ 国際誌 ]  [国際共著]

    記事・総説・解説・論説等(国際会議プロシーディングズ)  

     概要を見る

    The spectra of the Sloan Digital Sky Survey (SDSS) are being used to construct a catalogue of QSO absorption lines, for use in studies of abundances, relevant radiation fields, number counts as a function of redshift, and other matters, including the evolution of these parameters. The catalogue includes intervening, associated, and BAL absorbers, in order to allow a clearer definition of the relationships between these three classes. We describe the motivation for and the data products of the project to build the SDSS QSO absorption line catalogue. © 2005 International Astronomical Union.

    DOI

  • A search for galaxy clustering at z=4 using a Sloan Digital Sky Survey quasar pair

    Nakamura O, Fukugita M, Doi M, Kashikawa N, Schneider D. P

    Astronomical Society of the Pacific Conference Series   289   243 - 246  2003年05月   [ 国際誌 ]  [国際共著]

    記事・総説・解説・論説等(国際会議プロシーディングズ)  

  • Compariosn of Nucleosynthesis Models

    Osamu NAKAMURA

    Proceedings of the 187th Symposium of the International Astronomical Union     230  2002年   [ 国際誌 ]

    記事・総説・解説・論説等(国際会議プロシーディングズ)  

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他学部・他研究科等兼任情報

  • 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