Hostname: page-component-cd9895bd7-gbm5v Total loading time: 0 Render date: 2024-12-12T18:37:39.210Z Has data issue: false hasContentIssue false
  • English
  • Français

Far-Infrared [C II] Properties of Low-Metallicity Galaxies

Published online by Cambridge University Press:  14 August 2015

K. Mochizuki ,
T. Onaka  and
T. Nakagawa
K. Mochizuki
Affiliation:
Department of Astronomy, University of Texas Austin, TX 78712, USA
T. Onaka
Affiliation:
Department of Astronomy, University of Tokyo Bunkyou, Tokyo 113, Japan
T. Nakagawa
Affiliation:
The Institute of Space and Astronautical Science 3-1-1 Yoshinodai, Kanagawa 229, Japan

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The line flux ratio of the [C II] 158 μm fine-structure (2P3/2 → 2P3/2) emission to CO rotational emission is a probe of the intensity of the interstellar UV radiation in galaxies. The largest values for the [C II]/CO (J = 1-0) line ratios are found in starburst galaxies, none of which, however, show values larger than 6 ×103 (Stacey et al. 1991). The exception ([CII]/CO ≃ 2 × 104) are galaxies of Magellanic type which have low metallicity, an intense interstellar UV field, and irregular morphology (Table 1).

Mochizuki et al. (1994) showed that the two conditions, a low metallicity and an intense UV field are expected to result in the large [C II]/CO ratios in the Magellanic types. These conditions are likely to be common in more massive galaxies as well, but at an early epoch in their evolution. This suggests that bright [C II] emission can be a good indicator of young galaxies. However, the metal-poor galaxies previously observed in the [C II] line were exclusively Magellanic types. Observations of different types of dwarf galaxies are necessary to help us understand the physical conditions in the interstellar medium of low-metallicity systems.

Type
II. Joint Discussions
Information
Highlights of Astronomy , Volume 11 , Issue 1: Highlights of Astronomy. As presented at the XXIIIrd General Assembly of the IAU (Part A), 1997 , 1998 , pp. 123 - 124
Copyright
Copyright © Kluwer 1998

References

Lord, S.D., et al. 1995, in Airborne Astronomy Symposium on the Galactic Ecosystem: From Gas to Stars to Dust, ed. Haas, M.R., et al. (ASP Conf. Ser., 73), 151 Google Scholar
Maloney, P., and Black, J.H. 1988, ApJ, 325, 389 Google Scholar
Mochizuki, K., et al. 1994, ApJ, 430, L37 Google Scholar
Mochizuki, K. 1996, Ph. D. Thesis, University of Tokyo Google Scholar
Nakagawa, T., et al. 1995, ApJ, 455, L35 Google Scholar
Ohta, et al. 1996, Nature, 382, 426 Google Scholar
Skillman, E.D., Kennicutt, R.C., and Hodge, P.W. 1989, ApJ, 347, 875 Google Scholar
Stacey, G.J., et al. 1991, ApJ, 373, 423 Google Scholar
Tacconi, L.J., and Young, J.S. 1987, ApJ, 322, 681 Google Scholar