Michael Norbury

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We derive constraints on cosmological parameters and the properties of the lensing galaxies from gravitational lens statistics based on the final Cosmic Lens All Sky Survey data. For a flat universe with a classical cosmological constant, we find that the present matter fraction of the critical density is Omega(m)=0.31(+0.27)(-0.14) (68%)+0.12-0.10 (syst).(More)
High resolution MERLIN observations of a newly-discovered four-image gravitational lens system, B0128+437, are presented. The system was found after a careful reanalysis of the entire CLASS dataset. The MERLIN observations resolve four components in a characteristic quadruple-image configuration; the maximum image separation is 542 mas and the total flux(More)
We present a series of high resolution radio and optical observations of the CLASS gravitational lens system B1152+199 obtained with the Multi-Element Radio-Linked Interferometer Network (MERLIN), Very Long Baseline Array (VLBA) and Hubble Space Telescope (HST). Based on the milliarcsecond-scale substructure of the lensed radio components and precise(More)
1 University of Manchester, Jodrell Bank Observatory, Macclesfield, Cheshire SK11 9DL 2 Kapteyn Astronomical Institute, Postbus 800, NL-9700 AV Groningen, the Netherlands California Institute of Technology, Pasadena, CA 91125, USA Netherlands Foundation for Research in Astronomy, Postbus 2, NL-7990 AA Dwingeloo, the Netherlands 5 National Radio Astronomy(More)
HST V and I-band observations show that the gravitational lens B1359+154 consists of six images of a single zs = 3.235 radio source and its star-forming host galaxy, produced by a compact group of galaxies at zl ' 1. VLBA observations at 1.7 GHz strongly support this conclusion, showing six compact cores with similar low-frequency radio spectra. B1359+154(More)
We report the discovery of a new two-image gravitational lens system, CLASS B2319]051, from the Cosmic Lens All-Sky Survey. Radio imaging with the Very Large Array (VLA) and Multielement Radiolinked Interferometer Network (MERLIN) shows two compact components with a Ñux density ratio of ^5:1, separated by Observations with the Very Long Baseline Array(More)
We report on the discovery of the new gravitational lens system CLASS B0631+519. Imaging with the Very Large Array, the Multi-Element Radio-Linked Interferometer Network (MERLIN) and the Very Long Baseline Array (VLBA) reveals a doubly imaged flat-spectrum radio core, a doubly imaged steep-spectrum radio lobe and possible quadruply imaged emission from a(More)
The Cosmic Lens All-Sky Survey (CLASS) is an international collaborative programme which has obtained high-resolution radio images of over 10 000 flat-spectrum radio sources in order to create the largest and best-studied statistical sample of radio-loud gravitationally lensed systems. With this survey, combined with detailed studies of the lenses found(More)
We report the discovery of a new gravitational lens system from the CLASS survey. Radio observations with the VLA, the WSRT and MERLIN show that the radio source B0850+054 is comprised of two compact components with identical spectra, a separation of 0.7 arcsec and a flux density ratio of 6:1. VLBA observations at 5 GHz reveal structures that are consistent(More)
OBJECTIVES This paper investigates the interplay between group identification (i.e., the extent to which one has a sense of belonging to a social group, coupled with a sense of commonality with in-group members) and four types of health behaviour, namely physical exercise, smoking, drinking, and diet. Specifically, we propose a positive relationship between(More)