• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to project page

2005 Fiscal Year Final Research Report Summary

Theoretical study for the fundamental physical processes of the star formation in proto-galactic clouds and the formation of cosmological first luminous objects.

Research Project

Project/Area Number 14540227
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field Astronomy
Research InstitutionNiigata University

Principal Investigator

NISHI Ryoichi  Niigata University, Institute of Science and Technology, Associate Professor -> 新潟大学, 自然科学系, 助教授 (80252419)

Project Period (FY) 2002 – 2005
Keywordsgalaxy formation / star formation / primordial gas / cosmology
Research Abstract

We investigated on the formation process of early cosmological luminous objects and discussed them for the observational corroboration of physical scenarios. Firstly, we studied the star formation process in the primordial gas, and estimate the emission line luminosities of H_2 and HD molecules, which are important because they are expected to characterize the primordial star formation process. For the formation process of the first generation stars, HD is not important. But for the star formation in the massive proto-galactic clouds, HD plays important roles as coolant. LiH molecule never plays important role. Secondly, we studied the evolution of the filamentary clouds, which is formed via the fragmentation process of the proto-galactic clouds and important for the formation of the star forming core. In the collapse and the fragmentation processes, the fraction of the dark matter component is very significant. Considering the filaments formed in the gravitational potential well, it is impossible to collapse enough before fragmentation. Thus, efficient star formation is expected to be impossible. We also estimated the emission line luminosities of H_2 and HD molecules for the filaments without dark matter, which are the mother objects of the star formation cores. Finally, estimating the primordial star formation rate in the proto-galactic clouds, we discuss the observational possibility of the formation process of early cosmological luminous objects. Because of the redshift effects, it is important to observe mid-infrared radiation. Thus, SPICA (Space Infrared Telescope for Cosmology and Astrophysics) has the best chance for the observational corroboration in the next generation facilities. If the star formation rate in the primordial gas is as large as the star forming rate of the usual star burst galaxies, SPICA can observe the primordial molecular lines from the first forming process of early cosmological luminous objects.

Research Products

(7 results)

All 2005 2004 2003

All Journal Article

  • [Journal Article] H_2 Line Emission Associated with the Formation of the First Stars2005

    • Author(s)
      H.Mizusawa, K.Omukai R.Nishi
    • Journal Title

      Publications of the Astronomical Society of Japan 57

      Pages: 951-967

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] H_2 Line Emission Associated with the Formation of the First Stars2005

    • Author(s)
      H.Mizusawa, K.Omukai, R.Nishi
    • Journal Title

      Publications of the Astronomical Society of Japan 57

      Pages: 951-967

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] H_2 Line Emission Associated with the Formation of the First Stars2004

    • Author(s)
      H.Mizusawa, R.Nishi, K.Omukai
    • Journal Title

      Publications of the Astronomical Society of Japan 56

      Pages: 487-495

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Star Formation in the Primordial Gas : Overview2003

    • Author(s)
      R.Nishi
    • Journal Title

      Progress of Theoretical Physics Supplement 147

      Pages: 1-9

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] On the Fragment Mass Scale of Primordial Gas Clouds --Effects of Dark Matter Component--2003

    • Author(s)
      R.Nishi
    • Journal Title

      Progress of Theoretical Physics Supplement 147

      Pages: 85-98

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] On the Feedback Effects of the First Generation Stars2003

    • Author(s)
      R.Nishi
    • Journal Title

      Progress of Theoretical Physics Supplement 147

      Pages: 99-108

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] On the Fragment Mass Scale of Primordial Gas Clouds--Effects of Dark Matter Component--2003

    • Author(s)
      R.Nishi
    • Journal Title

      Progress of Theoretical Physics Supplement 147

      Pages: 85-98

    • Description
      「研究成果報告書概要(欧文)」より

URL: 

Published: 2007-12-12  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi