8 papers
Mapping the Remote Milky Way Halo using BHB stars at 70 < r < 130 kpc
L. Clewley, S. J. Warren, P. C. Hewett +2
We increase the number of remote halo tracers by using blue horizontal branch (BHB) stars out to Galactocentric distances of 130 kpc. We use SDSS EDR photometry and the VLT to dete…
WFCAM, UKIDSS, and z=7 quasars
Steve Warren, Paul Hewett
We estimate the number of z~7 quasars that will be discovered in the Large Area Survey (LAS) element of the UKIRT Infrared Deep Sky Survey (UKIDSS). The LAS will cover 4000 sq degs…
A spectroscopic survey for strong galaxy-galaxy lenses
J. P. Willis, P. C. Hewett, S. J. Warren +1
We present a spectroscopic survey for strong galaxy-galaxy lenses. Exploiting optimal sight-lines to massive, bulge-dominated galaxies at redshifts with wide-field, mu…
A microlensing search for cold molecular clouds in Virgo
H Tadros, S J Warren, P C Hewett
We report preliminary results from a first season of photometric monitoring of 600 quasars behind the Virgo galaxy cluster with the aim of detecting microlensing by the cluster dar…
High-Redshift Gravitationally Lensed Galaxies and Tunable Filter Imaging
Paul C. Hewett, Stephen J. Warren, Jon P. Willis +2
Most surveys for multiply-imaged gravitational lenses, outside of rich galaxy clusters, are based on sifting through large samples of distant sources to identify the rare examples…
A VLT colour image of the optical Einstein ring 0047-2808
S. J. Warren, G. F. Lewis, P. C. Hewett +3
The optical Einstein ring 0047-2808 was imaged by the VLT UT1 during the science verification programme. The ring is the image of a high-redshift z=3.595 star-forming galaxy, with…