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Neutral Gas Outside the Disks of Local Group Galaxies

Published online by Cambridge University Press:  21 March 2017

Felix J. Lockman*
Affiliation:
National Radio Astronomy Observatory †, Green Bank National Observatory, P.O. Box 2, Green Bank, WV 24944USA email: [email protected]
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Abstract

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Of the three kinds of neutral gas found outside the stellar disks of Local Group galaxies, only the products of interaction, like the Magellanic Stream, have a clearly understandable origin. Both the high-velocity clouds and the faint H I between M31 and M33 remain a mystery. New observations of the region between M31 and M33 with the Green Bank Telescope show that the H I there resides in clouds with a size and mass similar to that of dwarf galaxies, but without stars. These clouds might be products of an interaction, or condensations in the hot circumgalactic medium of M31, but both these models have difficulties. The prevalence of clouds like this in the Local Group remains to be determined.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2017 

References

Adams, E. A. K., Giovanelli, R., & Haynes, M. P. 2013, ApJ, 768, 77 Google Scholar
Bekki, K. 2008, MNRAS, 390, L24 CrossRefGoogle Scholar
Besla, G. 2015, arXiv:1511.03346Google Scholar
Braun, R. & Thilker, D. A. 2004, A&A, 417, 421 Google Scholar
Fox, A. J., Wakker, B. P., Barger, K. A., et al. 2014, ApJ, 787, 147 CrossRefGoogle Scholar
Heald, G., Józsa, G., Serra, P., et al. 2011, A&A, 526, A118 Google Scholar
Lehner, N. & Howk, J. C. 2011, Science, 334, 955 Google Scholar
Lehner, N., Howk, J. C., & Wakker, B. P. 2015, ApJ, 804, 79 CrossRefGoogle Scholar
Lewis, G. F., Braun, R., McConnachie, A. W., et al. 2013, ApJ, 763, 4 CrossRefGoogle Scholar
Lockman, F. J., Murphy, E. M., Petty-Powell, S., & Urick, V. J. 2002, ApJ, 140, 331 Google Scholar
Lockman, F. J., Benjamin, R. A., Heroux, A. J., & Langston, G. I. 2008, ApJ, 679, L21 Google Scholar
Mathewson, D. S., Cleary, M. N., & Murray, J. D. 1974, ApJ, 190, 291 Google Scholar
Muller, C. A., Oort, J. H., & Raimond, E. 1963, Acad. Sci. Paris Comptes Rendus, 257, 1661 Google Scholar
Nidever, D. L., Majewski, S. R., Butler, Burton W., & Nigra, L. 2010, ApJ, 723, 1618 CrossRefGoogle Scholar
Nidever, D. L., Ashley, T., Slater, C. T., et al. 2013, ApJ, 779, L15 Google Scholar
Nielsen, N. M., Churchill, C. W., & Kacprzak, G. G. 2013, ApJ, 776, 115 Google Scholar
Oort, J. H. 1966, Bulletin of the Astronomical Institutes of the Netherlands, 18, 421 Google Scholar
Putman, M. E., Staveley-Smith, L., Freeman, K. C., et al. 2003, ApJ, 586, 170 CrossRefGoogle Scholar
Putman, M. E., Peek, J. E. G., & Joung, M. R. 2012, Ann. Rev. Astr. Ap., 50, 491 CrossRefGoogle Scholar
Shaya, E. J. & Tully, R. B. 2013, MNRAS, 436, 2096 Google Scholar
Shull, J. M., Jones, J. R., Danforth, C. W., & Collins, J. A. 2009, ApJ, 699, 754 Google Scholar
Thilker, D. A., Braun, R., Walterbos, R. A. M., et al. 2004, ApJ, 601, L39 Google Scholar
Wakker, B. P. & van Woerden, H. 1997, ARA&A, 35, 217 Google Scholar
Walter, F., Brinks, E., de Blok, W. J. G., et al. 2008, AJ 136 25632647 CrossRefGoogle Scholar
Wannier, P. & Wrixon, G. T. 1972, ApJ, 173, L119 CrossRefGoogle Scholar
Westmeier, T., Brüns, C., & Kerp, J. 2008, MNRAS, 390, 1691 Google Scholar
Wolfe, S. A., Pisano, D. J., Lockman, F. J., et al. 2013, Nature, 497, 224 Google Scholar
Wolfe, S. A., Lockman, F. J., & Pisano, D. J. 2016, ApJ, 816, 81 Google Scholar