Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-27T07:13:28.148Z Has data issue: false hasContentIssue false

The Absence of 1584 MHz Maser Emission from 18OH

Published online by Cambridge University Press:  25 April 2016

J. L. Caswell
Affiliation:
Division of Radiophysics, CSIRO, Sydney
R. F. Haynes
Affiliation:
Division of Radiophysics, CSIRO, Sydney

Extract

In the terrestrial environment the abundance ratio of 18O to the common oxygen isotope 16O is about 1 in 490. Measurements of hydroxyl absorption in the interstellar medium show that 18OH as well as 16OH can be detected towards Sgr A and Sgr B2 (Gardner et al. 1970; Wilson and Barrett 1970; Williams and Gardner 1981); in these two galactic centre regions the 18OH isotopic species has an abundance relative to 16OH of about 1 in 220, somewhat greater than the terrestrial ratio of 18O to 16O.

Type
Contributions
Copyright
Copyright © Astronomical Society of Australia 1981

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Andersson, C., Johansson, L. E. B., Goss, W. M., Winnberg, A., and Nguyen-Quang-Rieu, Astron. Astrophys., 30, 475 (1974).Google Scholar
Ball, J. A., and Penfield, Astrophys. J., 160, 349 (1970).Google Scholar
Caswell, J. A., and Haynes, R. F. Mon Not. R. Astron. Soc., 173, 649 (1975).Google Scholar
Caswell, J. L., Haynes, R. F., Goss, W. M., and Mebold, U. Aust. J. Phys. (in press).Google Scholar
Cook, A. H., ‘Celestial Masers’, Cambridge Univ. Press (1977).Google Scholar
Elitzur, M., Goldreich, P., and Scoville, N. Astrophys. J., 205, 384 (1976).Google Scholar
Epchtein, N., Guibert, J. Nguyen-Quang-Rieu, , Turon, P., and Wamsteker, W. Astron. Astrophys., 85, L1 (1980).Google Scholar
Forrest, W. J., McCarthy, J. F., and Houck, J. R. Astrophys. J., 233 611 (1979).Google Scholar
Gardner, F. F., McGee, R. X., and Sinclair, M. W., Astrophys.Lett., 7, 79 (1970).Google Scholar
Kegel, W. H., and Varshalovich, D. A. Nature, 286, 136 (1980).Google Scholar
Robinson, B. J., Caswell, J. L., and Goss, W. M. Astrophys. Lett., 7, 29 (1965).Google Scholar
Weaver, H., Williams, D. R. W., Dieter, N. H., and Lum, W. T. Nature, 208, 29 (1965).Google Scholar
Werner, M. W., Beckwith, S., Gatley, I., Sellgren, K., Berriman, G., and Whiting, D. L. Astrophys., J., 239, 540 (1980).Google Scholar
Williams, D. R., and Gardner, F. F. Astrophys. J. Lett, (in press).Google Scholar
Wilson, W. J., and Barrett, A. H. Astrophys. Lett., 6, 231 (1970).Google Scholar
Wilson, W. J., and Barrett, A. H. Astron. Astrophys., 17, 385 Google Scholar