Discovery of a high-redshift Einstein ring
Abstract
We report the discovery of a partial Einstein ring of radius 1.48 arcsec produced by a massive (and seemingly isolated) elliptical galaxy. The spectroscopic follow-up at the VLT reveals a 2Lstar galaxy at z=0.986, which is lensing a post-starburst galaxy at z=3.773. This unique configuration yields a very precise measure of the mass of the lens within the Einstein radius, (8.3 ± 0.4) × 1011h70-1M⊙ . The fundamental plane relation indicates an evolution rate of dlog (M/L)B / dz = -0.57±0.04, similar to other massive ellipticals at this redshift. The source galaxy shows strong interstellar absorption lines indicative of large gas-phase metallicities, with fading stellar populations after a burst. Higher resolution spectra and imaging will allow the detailed study of an unbiased representative of the galaxy population when the universe was just 12% of its current age.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- June 2005
- DOI:
- arXiv:
- arXiv:astro-ph/0504585
- Bibcode:
- 2005A&A...436L..21C
- Keywords:
-
- cosmology: observations;
- gravitational lensing;
- galaxies: high-redshift;
- ellipticals;
- evolution;
- FOR J0332-3557;
- Astrophysics
- E-Print:
- 5 pages, 3 figures, accepted in A&