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Phase Interchange of Galactic Interstellar Gas Explored by the Terahertz Heterodyne Sensing

Research Project

Project/Area Number 14204013
Research Category

Grant-in-Aid for Scientific Research (A)

Allocation TypeSingle-year Grants
Section一般
Research Field Astronomy
Research InstitutionThe University of Tokyo

Principal Investigator

YAMAMOTO Satoshi  The University of Tokyo, Graduate School of Science, Professor, 大学院・理学系研究科, 教授 (80182624)

Co-Investigator(Kenkyū-buntansha) OKA Tomoharu  The University of Tokyo, Graduate School of Science, Research Associate, 大学院・理学系研究科, 助手 (10291056)
NOGUCHI Takeshi  National Astronomy Observatory of Japan, Radioastronomy Division, Associate Professor, 電波天文学研究系, 助教授 (90237826)
池田 正史  理化学研究所, 計算科学技術推進室, 基礎科学特別研究員 (60344024)
Project Period (FY) 2002 – 2005
Project Status Completed (Fiscal Year 2005)
Budget Amount *help
¥56,160,000 (Direct Cost: ¥43,200,000、Indirect Cost: ¥12,960,000)
Fiscal Year 2005: ¥7,800,000 (Direct Cost: ¥6,000,000、Indirect Cost: ¥1,800,000)
Fiscal Year 2004: ¥7,670,000 (Direct Cost: ¥5,900,000、Indirect Cost: ¥1,770,000)
Fiscal Year 2003: ¥11,700,000 (Direct Cost: ¥9,000,000、Indirect Cost: ¥2,700,000)
Fiscal Year 2002: ¥28,990,000 (Direct Cost: ¥22,300,000、Indirect Cost: ¥6,690,000)
KeywordsStar Formation / Submillimeter-wave / Molecular Cloud / Galaxy / Radio Telescope / Atomic Carbon / Terahertz / Superconductor / 熱伝導
Research Abstract

In this study, we focused on the phase interchange of interstellar gas in the Galaxy, and conducted the following two researches.
The first one is a development of the THz heterodyne receiver using the superconductive HEB mixer in order to explore the distribution of the nitrogen ion line (1.46THz). With this line, we can study a role of plasma gas in formation and evolution of molecular clouds. By using the facilities at Nobeyama Radio Observatory, we have fabricated a diffusion cooled HEB mixer element which has a microbridge structure of Nb with a size of a few 100nm. After many trials, we finally established the fabrication process using the liftoff method. The mixer element was mounted on the waveguide mixer block for the RF test, and we have confirmed the mixer operation at 800GHz. Although we have still some problems to overcome, we were able to form a strong base toward realizing the HEB mixer receiver for the THz astronomy.
Along with the above development study, we studied formation and evolution of molecular clouds by observing the fine structure line of the atomic carbon with the Mount Fuji submillimeter-wave telescope. Particularly, we observed bright rimmed globules, which are illuminated by strong UV radiation from a nearby OB stars. In a young bright rimmed globule, IC1396, we found that the distribution of the atomic carbon extends over the entire of the clouds, not concentrating at the bright rim. On the other hand, we found a peak of the atomic carbon emission at the bright rim position in a rather old globule, λ Ori. This indicates that the atomic carbon gradually changes into CO as the cloud evolves, and that it only exists in the PDR layer illuminated by OB stars. Therefore we further confirmed that the atomic carbon can be a good tracer to study formation and evolution of molecular clouds.

Report

(5 results)
  • 2005 Annual Research Report   Final Research Report Summary
  • 2004 Annual Research Report
  • 2003 Annual Research Report
  • 2002 Annual Research Report
  • Research Products

    (24 results)

All 2006 2005 2004 2003 Other

All Journal Article (16 results) Publications (8 results)

  • [Journal Article] Atomic Carbon in the AFGL333 Cloud2006

    • Author(s)
      Takeshi Sakai
    • Journal Title

      Astrophys. J. in press

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Detection of HCOOCH_3 toward a Low-Mass Protostar NGC1333 IRAS4B2006

    • Author(s)
      Nami Sakai
    • Journal Title

      Publ. Astron. Soc. Japan 58

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Detection of HCOOCH_3 toward a Low Mass Protostar NGC1333 IRAS4B2006

    • Author(s)
      Nami Sakai et al.
    • Journal Title

      Publ.Astron.Soc. Japan 58

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Atomic Carbon in the Southern Milky Way2005

    • Author(s)
      Tomoharu Oka
    • Journal Title

      Astrophysical Journal 623

      Pages: 889-889

    • Related Report
      2005 Annual Research Report
  • [Journal Article] Atomic Carbon in the Southern Milky Way2005

    • Author(s)
      Tomoharu Oka
    • Journal Title

      The Astrophysical Journal (印刷中)

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Molecular Line Observations of Carbon-Chain-Producing Regions L1495B and L1521B2004

    • Author(s)
      Tomoya Hirota
    • Journal Title

      Astrophys. J. 617

      Pages: 399-405

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Submillimeter-wave CI Spectral Lines from the NGC1333 Region2004

    • Author(s)
      Tomoharu Oka
    • Journal Title

      Astrophys. J. 602

      Pages: 803-815

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Molecular Line Observations of Carbon-Chain-Producing Regions L1495B and L1521B2004

    • Author(s)
      Tomoya Hirota et al.
    • Journal Title

      Astrophys.J. 617

      Pages: 399-405

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Submillimeter-wave CI Spectral Line from the NGC1333 Region2004

    • Author(s)
      Tomoharu Oka et al.
    • Journal Title

      Astrophys.J. 602

      Pages: 803-815

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] CI Submillimeter-wave Line Emission from the NGC 1333 Region2004

    • Author(s)
      Tomoharu Oka
    • Journal Title

      The Astrophysical Journal 612

      Pages: 803-815

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Molecular Line Observation of Carbon-Chair-Producing Regions L1495B and L1521B2004

    • Author(s)
      Tomoya Hirota
    • Journal Title

      The Astrophysical Journal 617

      Pages: 399-405

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Mapping Observations of DNC and HN^13C in Dark Cloud Cores2003

    • Author(s)
      Tomoya Hirota
    • Journal Title

      Astrophys. J. 594

      Pages: 859-868

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Distribution of the [CI]Emission in the ρ Ophiuchi Dark Cloud2003

    • Author(s)
      Kazuhisa Kamegai
    • Journal Title

      Astrophys. J. 589

      Pages: 378-385

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Mapping Observations of DNC and HN^<13>C in Dark Cloud Cores2003

    • Author(s)
      Tomoya Hirota et al.
    • Journal Title

      Astrophys.J. 594

      Pages: 859-878

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Distribution of the [CI] emission in the ρOphiuchi Dark Cloud2003

    • Author(s)
      Kazuhisa Kamegai et al.
    • Journal Title

      Astrophys.J. 589

      Pages: 378-385

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Atomic Carbon in the AFGL333 Cloud

    • Author(s)
      Takeshi Sakai et al.
    • Journal Title

      Astrophys.J. (in press)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Publications] Kazuhisa Kamegai: "Distribution of the [C I]Emission in the ρ Ophiuchi Dark Cloud"The Astrophysical Journal. 589. 378-385 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] Tomoya Hirota: "Mapping Observations of DNC and HN^<13>C in Dark Cloud Cores"The Astrophysical Journal. 594. 859-868 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] Eunsook Kim: "Fourier transform millimeter-wave spectroscopy of the ethyl radical in the electronic ground state"Journal of Molecular Spectroscopy. 219. 296-303 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] Tomoharu Oka: "CI Submillimeter-wave Line Emission from the NGC 1333 Region"The Astrophysical Journal. (印刷中). (2004)

    • Related Report
      2003 Annual Research Report
  • [Publications] Tomoya Hirota: "L1521E : A Starless Core in the Early Evolutionary Stage?"Astrophysical Journal. 565. 359-363 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] Masafumi Ikeda: "The Distribution of Atomic Carbon in the Orion Giant Molecular Cloud 1"Astrophysical Journal Supplement Sereis. 139. 467-485 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] Masafumi Ikeda: "The H13CN/HC15N Abundance Ratio in Dense Cores : Possible Source-to-Source Variation of Isotope Abundances?"Astrophysical Journal. 575. 250-256 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] Kazuhisa Kamegai: "Distribution of the [CI]Emission in the ρ Ophiuchi Dark Cloud"Astrophysical Journal. (In press).

    • Related Report
      2002 Annual Research Report

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Published: 2002-04-01   Modified: 2016-04-21  

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