Astron. Astrophys. 343, L35-L39 (1999)

Letter to the Editor

A VLT colour image of the optical Einstein ring 0047-2808 ^*

S.J. Warren ¹, G.F. Lewis ², P.C. Hewett ³, P. Moller ⁴, P. Shaver ⁴ and A. Iovino <sup>5

1</sup> Blackett Laboratory, Imperial College of Science Technology and Medicine, Prince Consort Rd, London SW7 2BZ, UK (s.j.warren@ic.ac.uk)
² Department of Physics and Astronomy, University of Victoria, PO Box 3055, Victoria BC, V8W 3P7, Canada (gfl@almuhit.phys.uvic.ca)
and Astronomy Department, University of Washington, Box 351580, Seattle, WA 98195-1580, USA
³ Institute of Astronomy, Madingley Road, Cambridge CB3 0HA, UK (phewett@ast.cam.ac.uk)
⁴ European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching bei München, Germany (pmoller; pshaver@eso.org)
⁵ Osservatorio Astronomico di Brera, Via Brera 28, I-20121 Milano, Italy (ovino@brera.mi.astro.it)

Received 1 December 1998 / Accepted 19 January 1999

Abstract

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 star-forming galaxy, with strong Ly emission at 5589Å, gravitationally lensed by a massive early-type galaxy at . Relative to earlier NTT data the high signal-to-noise ratio of the VLT Ly narrow-band image allows much improved constraints to be placed on the surface-brightness profile of the source and on the mass, leading to a measured mass-to-light ratio of for the deflector galaxy. We have combined the VLT B-band and Ly narrow-band images with a K-band image obtained at UKIRT to produce a deep colour image of the system.

Key words: galaxies: formation cosmology: gravitational lensing

* Based on observations obtained at the European Southern Observatory, Paranal, Chile, and the United Kingdom Infrared Telescope, Hawaii

Send offprint requests to: S.J. Warren

SIMBAD Objects

Contents

• 1. Introduction
• 2. Observations and data reduction
  • 2.1. VLT imaging
  • 2.2. UKIRT imaging
  • 2.3. Results
• 3. Gravitational lens model
• Acknowledgements
• References

© European Southern Observatory (ESO) 1999

Online publication: March 1, 1999
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