H2 line emission associated with the formation of the first stars

Hiromi Mizusawa, Ryoichi Nishi, Kazuyuki Omukai

研究成果: Article査読

11 被引用数 (Scopus)


Molecular hydrogen (H2) line radiation emitted in the formation events of first-generation stars is evaluated in a discussion of its detectability by future observational facilities. H2 luminosity evolution from the onset of prestellar collapse until the formation of a ∼ 100 M protostar is followed. Calculations are extended not only to the early phase of the runaway collapse, but also to the later phase of accretion, whose observational features have not been studied before. Contrary to the runaway collapse phase, where the pure-rotational lines are always dominant, in the accretion phase rovibrational line emission becomes prominent. The maximum luminosity is also attained in the accretion phase for strong emission lines. The peak intensity of the strongest rovibrational line reaches ∼ 10-29 W m-2, corresponding to the flux density of 10-5 μJy, for a source at the typical redshift of first-generation star formation, 1 + z = 20. Although the redshifted rovibrational H2 emission from such an epoch falls in the wavelength range of the next-generation infrared satellite, Space Infrared Telescope for Cosmology and Astrophysics, for exceeding the detection threshold, 107 such protostars are required to reach the maximum luminosity simultaneously in a pregalactic cloud. It is improbable that this condition is satisfied in a realistic scenario of early structure formation.

ジャーナルPublications of the Astronomical Society of Japan
出版ステータスPublished - 2004

ASJC Scopus subject areas

  • 天文学と天体物理学
  • 宇宙惑星科学


「H2 line emission associated with the formation of the first stars」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。