首页 | 本学科首页   官方微博 | 高级检索  
     


VLA 8.4-GHz monitoring observations of the CLASS gravitational lens B1933+503
Authors:A. D. Biggs  E. Xanthopoulos  I. W. A. Browne  L. V. E. Koopmans   C. D. Fassnacht
Affiliation:University of Manchester, Jodrell Bank Observatory, Macclesfield, Cheshire SK11 9DL;University of Groningen, Kapteyn Astronomical Institute, Postbus 800, 9700 AV Groningen, the Netherlands;National Radio Astronomy Observatory, PO Box 0, Socorro, NM 87801, USA
Abstract:The complex 10-component gravitational lens system B1933+503 has been monitored with the Very Large Array (VLA) during the period 1998 February–June with a view to measuring the time delay between the four compact components and hence to determine the Hubble parameter H 0. Here we present the results of an 'A' configuration 8.4-GHz monitoring campaign that consists of 37 epochs with an average spacing of 2.8 d. The data have yielded light curves for the four flat-spectrum radio components (components 1, 3, 4 and 6). We observe only small flux density changes in the four flat-spectrum components that we do not believe are predominantly intrinsic to the source. Therefore the variations do not allow us to determine the independent time delays in this system. However, the data do allow us to accurately determine the flux density ratios between the four flat-spectrum components. These will prove important as modelling constraints and could prove crucial in future monitoring observations should these data show only a monotonic increase or decrease in the flux densities of the flat-spectrum components.
Keywords:galaxies: individual: B1933+503    cosmology: observations    gravitational lensing
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号