Hostname: page-component-586b7cd67f-t8hqh Total loading time: 0 Render date: 2024-11-29T09:40:01.951Z Has data issue: false hasContentIssue false
  • English
  • Français

Discovery of Intergalactic H II Regions

Published online by Cambridge University Press:  26 May 2016

E. V. Ryan-Weber ,
M. E. Putman ,
K. C. Freeman ,
G. R. Meurer  and
R. L. Webster
E. V. Ryan-Weber
Affiliation:
University of Melbourne, Australia
M. E. Putman
Affiliation:
CASA, University of Colorado, USA
K. C. Freeman
Affiliation:
RSSA, Australian National University, Australia
G. R. Meurer
Affiliation:
The Johns Hopkins University, USA
R. L. Webster
Affiliation:
University of Melbourne, Australia

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 have discovered a number of very small isolated H II regions 20-30 kpc from their nearest galaxy. The H II regions appear as tiny emission line dots (ELdots) in narrow band images obtained by the NOAO Survey for Ionization in Neutral Gas Galaxies (SINGG). We have spectroscopic confirmation of 5 isolated H II regions in 3 systems. The Hα luminosities of the H II regions are equivalent to the ionizing flux of only 1 large or a few small OB stars each. These stars appear to have formed in situ and represent atypical star formation in the low density environment of galaxy outskirts. In situ star formation in the intergalactic medium offers an alternative to galactic wind models to explain metal enrichment. In interacting systems (2 out of 3), isolated H II regions could be a starting point for tidal dwarf galaxies.

Type
Part 4. Recycling
Information
Symposium - International Astronomical Union , Volume 217: Recycling Intergalactic and Interslettar Matter , 2004 , pp. 492 - 497
Copyright
Copyright © Astronomical Society of the Pacific 2004 

References

Aloisi, A., Savaglio, S., Heckman, T.M., Hoopes, C.G., Leitherer, C., & Sembach, K.R. 2003, ApJ, 595, 760.CrossRefGoogle Scholar
Collins, J.A., Shull, J.M., & Giroux, M.L. 2003, ApJ, 585, 336.CrossRefGoogle Scholar
Ferguson, A.M.N., Gallagher, J.S., & Wyse, R.F.G. 1998a, AJ, 116, 673.CrossRefGoogle Scholar
Ferguson, A.M.N., Wyse, R.F.G., Gallagher, J.S., & Hunter, D.A. 1998b, ApJ, 506, L19.CrossRefGoogle Scholar
Gerhard, O., Arnaboldi, M., Freeman, K.C., & Okamura, S. 2002, ApJ, 580, 121.CrossRefGoogle Scholar
Kennicutt, R.C. 1998, ApJ, 498, 541.CrossRefGoogle Scholar
Maeder, A. 1992, A&A, 264, 105.Google Scholar
Meyer, M., et al. 2003, MNRAS, submitted.Google Scholar
Oosterloo, T., et al. 2003, these proceedings.Google Scholar
Prochaska, J.X. 2003, ApJ, 582, 49.CrossRefGoogle Scholar
Ryan-Weber, E., Webster, R., & Bekki, K. 2003a, in ASSL Vol. 281: The IGM/Galaxy Connection. The Distribution of Baryons at z=0, p. 223.CrossRefGoogle Scholar
Ryan-Weber, E.V., Webster, R.L., & Stavely-Smith, L. 2003b, MNRAS, 343, 1195.CrossRefGoogle Scholar
Ryan-Weber, E.V., et al. 2003c, AJ, submitted.Google Scholar
Sakai, S., Kennicutt, R.C., van der Hulst, J.M., & Moss, C. 2002, ApJ, 578, 842.CrossRefGoogle Scholar
Tripp, T.M., et al. 2002, ApJ, 575, 697.CrossRefGoogle Scholar
Vacca, W.D., Garmany, C.D., & Shull, J.M. 1996, ApJ, 460, 914.CrossRefGoogle Scholar
Verdes-Montenegro, L., Yun, M.S., Williams, B.A., Huchtmeier, W.K., Del Olmo, A., & Perea, J. 2001, A&A, 377, 812.Google Scholar