Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.mrao.cam.ac.uk/~anthony/latex/Biggs.ps Дата изменения: Thu Jun 22 22:43:36 2000 Дата индексирования: Tue Oct 2 02:14:28 2012 Кодировка: Поисковые слова: mercury surface

Time delay and H0 results from
JVAS/CLASS Gravitational Lens Systems
A.D. Biggs et al.
Jodrell Bank Observatory, U.K.
The JVAS and CLASS radio surveys have been very successful in
identifying new lens systems; to date 17 lens systems have been
discovered. Due to candidates being selected partly on the ba-
sis of having a at spectral index, the resulting lens systems are
almost invariably multiple images of compact radio cores. These
sources are ideal for time delay measurement, and subsequent H0
determination, as they are usually variable and relatively sim-
ple to model. So far three lens systems have had time delays
measured using radio interferometric monitoring with the Very
Large Array, constituting half of the lenses with published time
delays. The values of H0 derived from the JVAS/CLASS lens sys-
tem time delays, when combined with simple isothermal models
for the lensing galaxy, are all similar being in the range approxi-
mately 60{70 km s 1 Mpc 1 . Monitoring of JVAS/CLASS lenses
is an ongoing project, both to improve existing time delay mea-
surements and to determine time delays or test for variability in
newly identied lens systems.
Co-authors: L.V.E. Koopmans/Kapteyn Astronomical Institute,
the Netherlands, C.S. Fassnacht/NRAO, USA
1