Hostname: page-component-78c5997874-g7gxr Total loading time: 0 Render date: 2024-11-14T20:18:03.898Z Has data issue: false hasContentIssue false

Distribution of the H2O Masers in the Sagittarius B2 Core

Published online by Cambridge University Press:  23 September 2016

H. Kobayashi
Affiliation:
Nobeyama Radio Observatory, Minamimaki–mura, Minamisaku–gun, Nagano 384–13
M. Ishiguro
Affiliation:
Nobeyama Radio Observatory, Minamimaki–mura, Minamisaku–gun, Nagano 384–13
Y. Chikada
Affiliation:
Nobeyama Radio Observatory, Minamimaki–mura, Minamisaku–gun, Nagano 384–13
N. Ukita
Affiliation:
Nobeyama Radio Observatory, Minamimaki–mura, Minamisaku–gun, Nagano 384–13
K-I Morita
Affiliation:
Nobeyama Radio Observatory, Minamimaki–mura, Minamisaku–gun, Nagano 384–13
S. Okumura-kawabe
Affiliation:
Nobeyama Radio Observatory, Minamimaki–mura, Minamisaku–gun, Nagano 384–13 Department of Astronomy, Faculty of Science, University of Tokyo, Bunkyo–ku, Tokyo 113
T. Kasuga
Affiliation:
Nobeyama Radio Observatory, Minamimaki–mura, Minamisaku–gun, Nagano 384–13
R. Kawabe
Affiliation:
Nobeyama Radio Observatory, Minamimaki–mura, Minamisaku–gun, Nagano 384–13

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.

The distribution of H2O masers in the Sgr B2 core was observed with a 2.5′×2.5′ wide field and with 540 km s−1 total velocity coverage by the Nobeyama Millimeter Array. Thirty-nine resolved maser spots were detected with a relative positional accuracy of 0.3″, which are clustered into four separate regions. In Sgr B2 north, the cluster lies at the edge of the continuum ridge. One of the maser spots shows strong and wide velocity-spread emission, suggesting it may correspond to a center of star forming activity. In Sgr B2 main, the strong maser spots are projected just on the face of a compact HII region, and are red-shifted relative to the central velocity of the HII region. There are two possibilities to interpret our results in Sgr B2 (M). One is that the H2O maser spots are distributed around the HII region and are infailing to the HII region. The other is that the H2O maser sources are associated with the cloud in the foreground of the HII region.

Type
Observations of Discrete Sources
Copyright
Copyright © Kluwer 1989 

References

Benson, J.M., and Johnson, K.J. 1984, Astrophys. J., 277 181 Google Scholar
Downes, D. 1985, ‘H2O masers in Star-forming Regions’, Birth and Infacy of Stars, Les Houches 1983, eds. Lucas, R. and Omont, A. Google Scholar
Elmegreen, B.G. et al., 1980, Astrophys. J., 241, 1007 Google Scholar
Forster, J.R., et al., 1978, Astrophys. J., 221, 137 CrossRefGoogle Scholar
Garay, G., Reid, M.J., and Moran, J.M., 1985, Astrophys. J., 289, 681 Google Scholar
Gardner, F.F. et al., 1986, M.N.R.A.S., 218, 385 Google Scholar
Gardner, F.F., Whiteoak, J.B., and Palmer, P., 1987, M.N.R.A.S., 225, 467 Google Scholar
Genzel, R., Downes, D., and Bieging, J., 1976, M.N.R.A.S., 177, 101p Google Scholar
Genzel, R., and Downes, D., 1977, Astron. Astrophys. Suppl., 30, 145 Google Scholar
Genzel, R., et al., 1978, Astron. Astrophys. 66, 13 Google Scholar
Genzel, R., et al., 1981a, Astrophy. J., 244, 884 Google Scholar
Genzel, R., et al., 1981b, Astrophys. J., 247, 1039 Google Scholar
Goldsmith, P.F., Snell, R.L., and Lis, D.C., 1987 Astrophys. J., 313, L5 Google Scholar
Goldsmith, P.F. et al., 1987 Astrophys. J., 314, 525 Google Scholar
Högbom, J.A., 1974, Astron. Astrophys. Suppl. 15, 417 Google Scholar
Ishiguro, M., et al., 1984, Proceedings of the International Symposium on Millimeter and Submillimeter Wave Radio Astronomy, Granada Google Scholar
Kobayashi, H. et al., 1988, in preparation Google Scholar
Morris, M., 1976, Astrophys. J., 210, 100 Google Scholar
Reid, M.J. and Moran, J.M., 1981, Ann. Rev. Astron. Astrophys., 19, 231 CrossRefGoogle Scholar
Roelfsema, P.R., et al., 1987, Astron. Astrophys., 175, 219 Google Scholar
Schneps, M.H., 1981, Astrophys. J., 249, 124 CrossRefGoogle Scholar
Schwab, F., 1980, Proc. Soc. Photo-Opt. Instr. Eng., 231, 18 Google Scholar
Thompson, A.R., Moran, J.M., and Swenson, G.W., 1986, Interferometry and Aperture Synthesis in Radio Astronomy, 411417, John Wiley & Sons Google Scholar
Vogel, S.N., Genzel, R., and Palmer, P., 1987 Astrophys. J., 316, 243 Google Scholar