Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-26T22:25:28.359Z Has data issue: false hasContentIssue false
  • English
  • Français

Ionised Hydrogen at Large Galactocentric Distances

Published online by Cambridge University Press:  05 March 2013

J. Bland-Hawthorn
J. Bland-Hawthorn*
Affiliation:
Anglo-Australian Observatory, PO Box 296, Epping, NSW 2121, Australia; [email protected]
Rights & Permissions [Opens in a new window]

Abstract

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.

We summarise recent attempts to detect warm ionised gas at large galactocentric distances. This includes searches for gas at the edges of spirals, in between cluster galaxies, towards extragalactic HI clouds, and towards high-velocity clouds and the Magellanic Stream in the Galaxy. With the exception of extragalactic HI clouds, all of these experiments have proved successful. Within each class, we have only observed a handful of objects. It is premature to assess what fraction of the missing baryonic mass fraction might be in the form of ionised gas. But, in most cases, the detections provide a useful constraint on the ambient ionising flux, and, in the case of spiral edges, can even trace dark matter haloes out to radii beyond the reach of radio telescopes.

Keywords

galaxies: kinematics and dynamicsdark matter: cosmic radiation field: galactic radiation field
Type
Research Article
Information
Publications of the Astronomical Society of Australia , Volume 14 , Issue 1 , 1997 , pp. 64 - 68
Copyright
Copyright © Astronomical Society of Australia 1997

References

Arp, H. 1985, AJ, 90, 1012 Google Scholar
Barcone, X. R., Fabian, A. C., & Rees, M. J. 1991, Nature, 350, 685 Google Scholar
Bland-Hawthorn, J., Ekers, R. D., van Breugel, W., Koekemoer, A., & Taylor, K. 1995, ApJ, 447, L77 Google Scholar
Bland-Hawthorn, J., Freeman, K. C., & Quinn, P. J. 1996, ApJ, submittedGoogle Scholar
Bland-Hawthorn, J., & Maloney, P. R. 1997, ApJ, in pressGoogle Scholar
Bland-Hawthorn, J., Taylor, K., Veilleux, S., & Shopbell, P. L. 1994, ApJ, 437, L95 Google Scholar
Bland-Hawthorn, J., Veilleux, S., & Carignan, C. 1996, in preparationGoogle Scholar
Bochkarev, N. G., & Sunyaev, R. A. 1977, Soviet Astr., 21, 542 Google Scholar
Carr, B. J. 1994, ARA&A, 32, 531 Google Scholar
Chengalur, J. N., Giovanelli, R., & Haynes, M. P. 1995, AJ, 109, 2415 Google Scholar
Donahue, M., Aldering, G., & Stocke, J. 1995, ApJ, 450, 45 Google Scholar
Dove, J., & Shull, J. M. 1994, ApJ, 423, 196 Google Scholar
English, J. 1995, PhD thesis, Australian National University Google Scholar
Giovanelli, R., & Haynes, M. P. 1989, ApJ, 346, L5 Google Scholar
Haardt, F., & Madau, P. 1996, ApJ, 461, 20 Google Scholar
Haynes, M. P., & Roberts, M. S. 1979, ApJ, 227, 767 Google Scholar
Hegyi, D. J., & Olive, K. A. 1986, ApJ, 303, 56 Google Scholar
Hibbard, J. E., & Mihos, C. J. 1995, AJ, 110, 140 Google Scholar
Kuijken, K. 1996, in Dark and Visible Matter in Galaxies and Cosmological Implications McCain, C., Freeman, K. C., English, J., & Bland-Hawthorn, J. 1995, in preparationGoogle Scholar
Maloney, P. R. 1993, ApJ, 414, 41 Google Scholar
Patel, K., & Wilson, C. D. 1995, ApJ, 451, 607 Google Scholar
Pfenniger, D., Combes, F., & Martinet, L. 1994, A&A, 285, 79 Google Scholar
Reynolds, R. J., et al. 1986, ApJ, 309, L9 Google Scholar
Schneider, S. E., Helou, G., Salpeter, E. E., & Terzian, Y. 1983, ApJ, 273, L1 Google Scholar
Schneider, S. E., et al. 1989, AJ, 97, 666 Google Scholar
Sciama, D. W. 1995, MNRAS, 276, L1 Google Scholar
Sciama, D. W. 1996, Modem Cosmology and the Dark Matter Problem, 2nd edn (Cambridge Univ. Press)Google Scholar
Songaila, A., Bryant, W., & Cowie, L. L. 1989, ApJ, 345, L71 Google Scholar
Sunyaev, R. 1969, ApJ Lett., 3, 33 Google Scholar
Taylor, C. L., Brinks, E., Grashuis, R. M., & Skillman, E. D. 1995, ApJS, 99, 427;Google Scholar
erratum ApJS, 102, 89 Google Scholar
Vogel, S. N., Weymann, R., Rauch, M., & Hamilton, T. 1995, ApJ, 441, 162 Google Scholar
Weiner, B. J., & Williams, T. B. 1996, AJ, 111, 1156 Google Scholar
Williams, T. B., & Schommer, R. A. 1993, ApJ, 419, L53 Google Scholar