A perfect celebration of the centenary of Einstein's miracle year, a
"near perfect Einstein Ring"
has been found. An
Einstein Ring
is the manifestation of gravitational lensing caused by (near) perfect alignment of a source, an intermediate galaxy (the lens) and the observer (us).
The
Discovery of the First "Einstein Ring" Gravitational Lens (VLA History) was in 1979, and only a few are known, with only a few of those being "optical".
(For the record, Einstein's observation that Rings were theoretically possibe was not in the Miracle Year, and he discounted the possibility of ever observing one.)
- Universe Today via /.
Abstract [click thru for PS and PDF of full preprint]
We report the discovery of a partial Einstein ring of radius 1.48arcsec produced by a massive (and seemingly isolated) elliptical galaxy. The spectroscopic follow-up at the VLT reveals a 2L* 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, (8.3e11 +- 0.4)/h70 Msolar. The fundamental plane relation indicates an evolution rate of d [log (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.
