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Toward estimation of H(sub 0) from VLBI observations of the gravitational lens system 0957+561We have analyzed two epochs of 6 cm very long base interferometry (VLBI) observations of the two brightest images, A and B, of the gravitationally lensed quasar 0957+561 in a search for correlated structural evolution from which to estimate delta tau(sub BA), the difference in propagation time for light traveling between the quasar and Earth along the paths corresponding to these two images. However, we detected only marginal increases in the separation between the core and the innermost jet component in each image over the 2 year interval 1987-1989. Because monitoring image brightness variations has since led to apparently reliable estimates of delta tau(sub BA), we intend to use spatial variations in the relative magnification field across the extent of the images to constrain further the mass distribution of the lens, which is now the principal contributor to the uncertainty in estimates of H(sub 0) from this lens system.
Document ID
19950034838
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Campbell, R. M.
(Harvard University Cambridge, MA, United States)
Corey, B. E.
(Haystack Observatory, Westford, MA United States)
Falco, E. E.
(Harvard-Smithsonian Center for Astrophysics, Cambridge, MA United States)
Shapiro, I. I.
(Harvard University Cambridge, MA, United States)
Gorenstein, M. V.
(Millipore Corporation Milford, MA, United States)
Elosegui, P.
(Harvard-Smithsonian Center for Astrophysics, Cambridge, MA United States)
Marcaide, J. M.
(Instituto de Astrofisica de Andalucia Granada, Spain)
Alvi, K.
(Harvard University Cambridge, MA, United States)
Date Acquired
August 16, 2013
Publication Date
May 10, 1994
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 426
Issue: 2
ISSN: 0004-637X
Subject Category
Astronomy
Accession Number
95A66437
Funding Number(s)
CONTRACT_GRANT: NGT-50663
CONTRACT_GRANT: NSF AST-89-02087
Distribution Limits
Public
Copyright
Other

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