Density Bounding of Giant HII Regions and the Ionisation of the Diffuse Interstellar Medium

Publications of the Astronomical Society of Australia

J. E. Beckman¹ 

[1] M. Rozas

关键词: galaxies:ISM;    galaxies: spiral;    galaxies: intergalactic medium;    ISM: HII regions;   

DOI  :  10.1071/AS98083

学科分类：天文学(综合)

来源: CSIRO

【 摘 要 】

Three different types of evidence are presented in favour of the hypothesis that the HII regions in disk galaxies with Hα luminosities greater than a critical value of 1038·6 erg s−1 are density-bounded, and that the escaping Lyman continuum photons from these are the principal ionising agents for the diffuse ISM in disk galaxies. This has important implications for the ionisation of the intergalactic medium, and for computed star formation rates in spirals.

【 授权许可】

Unknown