Hostname: page-component-586b7cd67f-t8hqh Total loading time: 0 Render date: 2024-11-26T23:29:13.791Z Has data issue: false hasContentIssue false

A Search for Gravitational Milli–Lenses

Published online by Cambridge University Press:  25 May 2016

P.N. Wilkinson
Affiliation:
University of Manchester, NRAL, Jodrell Bank, Macclesfield, Cheshire, SK11 9DL, UK
D.R. Henstock
Affiliation:
University of Manchester, NRAL, Jodrell Bank, Macclesfield, Cheshire, SK11 9DL, UK
I.W.A. Browne
Affiliation:
University of Manchester, NRAL, Jodrell Bank, Macclesfield, Cheshire, SK11 9DL, UK
A.C.S. Readhead
Affiliation:
California Institute of Technology, OVRO, Robinson 105-24, Pasadena, CA 91125 USA
G.B. Taylor
Affiliation:
California Institute of Technology, OVRO, Robinson 105-24, Pasadena, CA 91125 USA
R.C. Vermeulen
Affiliation:
California Institute of Technology, OVRO, Robinson 105-24, Pasadena, CA 91125 USA
T.J. Pearson
Affiliation:
California Institute of Technology, OVRO, Robinson 105-24, Pasadena, CA 91125 USA
W. Xu
Affiliation:
California Institute of Technology, OVRO, Robinson 105-24, Pasadena, CA 91125 USA

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 searched for gravitational milli–lens systems by examining VLBI maps of ~ 300 flat–spectrum radio sources. So far we have followed up 7 candidates, with separations in the range 2–20 mas. None have been confirmed as lenses but several of them can not yet be definitively ruled out. If there are no milli-lenses in this sample then uniformly–distributed black holes of 106 to 108 M cannot contribute more than ~ 1% of the closure density.

Type
Part I: Invited Reviews
Copyright
Copyright © Kluwer 1996 

References

Carr, B. J. 1990, Comments on Astrophysics, 14, 257.Google Scholar
Gnedin, N. Yu., Ostriker, J. P. 1992, Astrophys. J., 400, 1.CrossRefGoogle Scholar
Henstock, D. R., Wilkinson, P. N., Taylor, G. B., Readhead, A. C. S. and Pearson, T. J., Astrophys. J. Suppl., submitted.Google Scholar
Kassiola, A., Kovner, I., Blandford, R. D. 1991, Astrophys. J., 381, 6.CrossRefGoogle Scholar
Nemiroff, R. J. and Bistolas, V. G. 1990, Astrophys. J. 358, 5.CrossRefGoogle Scholar
Ostriker, J. P. and Vietri, M. 1986, Astrophys. J., 300, 68.CrossRefGoogle Scholar
Pearson, T. J., Readhead, A. C. S. 1988, Astrophys. J., 328, 114.Google Scholar
Polatidis, A. G., Wilkinson, P. N., Xu, W., Readhead, A. C. S. and Pearson, T. J., 1994, Astrophys. J. Suppl., in press.Google Scholar
Press, W. H., Gunn, J. E. 1973, Astrophys. J., 185, 397.Google Scholar
Taylor, G. B., Readhead, A. C. S., Pearson, T. J., Henstock, D. R., and Wilkinson, P. N., Astrophys. J. Suppl., in press.Google Scholar
Thakkar, D.D., Xu, W., Readhead, A. C. S., Pearson, T. J., Polatidis, A. G. and Wilkinson, P. N. 1994, Astrophys. J. Suppl., in press.Google Scholar
Xu, W., Readhead, A. C. S., Pearson, T.J., Polatidis, A. G., Wilkinson, P. N. 1994, Astrophys. J. Suppl., in preparation.Google Scholar