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Multi-frequency VLBI Observations of the Gravitational Lens B0218+357

Published online by Cambridge University Press:  25 May 2016

R. W. Porcas  and
A. R. Patnaik
R. W. Porcas
Affiliation:
Max-Planck-Intitut fuer Radioastronomie, Bonn, Germany
A. R. Patnaik
Affiliation:
Max-Planck-Intitut fuer Radioastronomie, Bonn, Germany

Extract

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The gravitational lens system B0218+357 comprises 2 image components (A and B) and a radio ‘Einstein Ring’ (Patnaik et al, 1993). The redshift of the lens galaxy is 0.6847 (Browne et al, 1994) and that of the imaged source 0.96 (preliminary result; Lawrence et al, 1995). The separation of A and B, which are both flat-spectrum radio sources, is only 0.335 arcsec, leading to the hope that the lens is a single galaxy with a relatively simple mass distribution. Refsdal pointed out (1964) that a model of such a distribution, and a measurement of the time difference along the two image paths, leads to an estimate of the Hubble constant, independent of the usual steps in the distance ladder. B0218+357 is one of only a few lensed systems well suited for such measurements. A preliminary value of 12 days has been measured for the A-B time delay, derived from a comparison of the percentage polarisation variations of the images at 15GHz, using the VLA (Corbett et al, 1995).

Type
Properties of Radio Sources
Information
Symposium - International Astronomical Union , Volume 175: Extragalactic Radio Sources , 1996 , pp. 115 - 117
Copyright
Copyright © Kluwer 1996 

References

Browne, I.W.A. et al, 1993, MNRAS,263, L32 Google Scholar
Corbett, E. et al, 1996, Proc IAU Symp. 173, Astrophysical Applications of Gravitational Lensing, ed, Kochanek, C.S. and Hewitt, J.N., Kluwer, (in press) Google Scholar
Lawrence, C. et al,1996, Proc IAU Symp. 173, Astrophysical Applications of Gravitational Lensing, ed, Kochanek, C.S. and Hewitt, J.N., Kluwer, (in press) Google Scholar
Nair, S.,1996, Proc IAU Symp. 173, Astrophysical Applications of Gravitational Lensing, ed, Kochanek, C.S. and Hewitt, J.N., Kluwer, (in press) Google Scholar
Patnaik, A.R. et al, 1993, MNRAS , 261, 435 Google Scholar
Patnaik, A.R., Porcas, R.W. and Browne, I.W.A., 1995, MNRAS , 274, L5 Google Scholar
Porcas, R.W. and Patnaik, A.R., 1996, Proc IAU Symp. 173, Astrophysical Applications of Gravitational Lensing, ed, Kochanek, C.S. and Hewitt, J.N., Kluwer, (in press) Google Scholar
Refsdal, S., 1964, MNRAS , 123, 307 Google Scholar