Hostname: page-component-76fb5796d-x4r87 Total loading time: 0 Render date: 2024-04-26T14:02:47.071Z Has data issue: false hasContentIssue false

Masers as Kinematic Signposts in Star Formation Regions

Published online by Cambridge University Press:  25 May 2016

Ray P. Norris*
Affiliation:
CSIRO Australia Telescope National Facility, PO Box 76, Epping, NSW 1710, 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.

Masers have been well studied as indicators of star formation regions for over three decades. Their small size, high brightness, and narrow velocity width mean that we can measure their position and velocity with enormous accuracy, and so they stand out as high-precision signposts amidst the swirling gas that they sample. Nevertheless, in most cases the complexity of their kinematics has defied attempts to use them to unravel the processes of star formation. However, the last two or three years have seen a resurgence of interest in these masers because of exciting new evidence that, in some cases, they are tracing with high precision the kinematics of material in circumstellar disks around massive stars. The very existence of circumstellar disks around these massive stars is puzzling, and yet the maser results have now been confirmed by other data at radio and infrared wavelengths. In this paper I will review the current status of high-resolution maser observations, discuss some of the puzzles that are now confronting us, and speculate on where our current tentative steps may lead us.

Type
Part 3. Outflows, Shocks, PDRs and Masers
Copyright
Copyright © Astronomical Society of the Pacific 2000 

References

Batrla, W., Matthews, H.E., Menten, K.M., & Walmsley, C.M. 1987, Nature, 326, 49 CrossRefGoogle Scholar
Caswell, J.L., Vaile, R.A., Ellingsen, S.P., Whiteoak, J.B., & Norris, R.P. 1995a, MNRAS, 272, 96 CrossRefGoogle Scholar
Caswell, J.L., Vaile, R.A., Ellingsen, S.P., & Norris, R.P. 1995b, MNRAS, 274, 1126 Google Scholar
Ellingsen, S.P., Norris, R.P., & McCulloch, P.M. 1996b, MNRAS, 279, 101 CrossRefGoogle Scholar
Ellingsen, S.P., Von Bibra, M.L., McCulloch, P.M., Deshpande, A.A., Norris, R.P., & Phillips, C.J. 1996a, MNRAS, 280, 378 Google Scholar
Hollenbach, D., Johnstone, D., Lizano, S., & Shu, F. 1994, ApJ, 428, 654 Google Scholar
Kawamura, J.H. & Masson, C.R. 1998, ApJ, 509, 270 CrossRefGoogle Scholar
McLeod, G.C. & Gaylard, M.J. 1992, MNRAS, 256, 519 Google Scholar
Menten, K.M. 1991, ApJ, 380, L75 Google Scholar
Minier, V., Booth, R. S., & Conway, J. E. 1998, A&A, 336, L5 Google Scholar
Norris, R.P. & Booth, R.S. 1981, MNRAS, 195, 213 Google Scholar
Norris, R.P., Booth, R.S., & Diamond, P.J. 1982, MNRAS, 201, 209 CrossRefGoogle Scholar
Norris, R.P., Byleveld, S.E., Diamond, P.J., Ellingsen, S.P., Kesteven, M.J., McCulloch, P.M., Reynolds, J.E., Tzioumis, A.K., Takahashi, Y., Troup, E.R., & Wellington, K.J. 1998, ApJ, 508, 275 Google Scholar
Norris, R.P., Caswell, J.L., Gardner, F.F., & Wellington, K.J. 1987, ApJ, 321, L159 Google Scholar
Norris, R.P., McCutcheon, W.H., Caswell, J.L., Wellington, K.J., Reynolds, J.E., Peng, R.S., & Kesteven, M.J. 1988, Nature, 335, 149 Google Scholar
Norris, R.P., Whiteoak, J.B., Caswell, J.L., Wieringa, M.H., & Gough, R.G. 1993, ApJ, 412, 222 Google Scholar
Phillips, C.J., Norris, R.P., Ellingsen, S.P., & McCulloch, P.M. 1998, MNRAS, 300, 1131 Google Scholar
Reid, M.J., Haschick, A.D., Burke, B.F., Moran, J.M., Johnston, K.J., & Swenson, G.W. 1980, ApJ, 239, 89 Google Scholar
Stecklum, B., Henning, Th., Feldt, M., Hayward, T.L., Hoare, M.G., Hofner, P., Richter, S. 1998, AJ, 115, 767 Google Scholar
Walsh, A.J., Hyland, A.R., Robinson, G., & Burton, M.G. 1997, MNRAS, 291, 261 Google Scholar
Weaver, H.F., Williams, D.R.W., Dieter, N.H., & Lum, W.T. 1965, Nature, 208, 29 Google Scholar
Welch, W.J. & Marr, J. 1987, ApJ, 317, L21 Google Scholar
Wood, D.O.S. & Churchwell, E. 1989, ApJS, 69, 831 Google Scholar