Brian Nord and Elizabeth Buckley-Geer
A Case of Warped Space:
Confirming Strong Gravitational
Lenses Found in the
Dark Energy Survey
Spectroscopic observations with the Gemini Multi-Object
Spectrograph at Gemini South provide precise redshifts that
confirm strong gravitational lensing systems discovered in early
Dark Energy Survey (DES) data. These confirmations are the first
at galaxy- and galaxy-cluster scales in the multi-year effort of
lens follow-up enabled by a Large and Long Program.
Massive astronomical objects sufficiently warp space-time to change the path of light on its
way from distant galaxies to an observer. Consequently, strong gravitational lensing systems
are revealed to us by the distorted images of these galaxies.
Most of the strong lensing systems discovered during the last decade were found by searching through existing data or through new observational campaigns. These investigations
across many wavebands — from the optical to the millimeter — have resulted in ~ 1,000
candidates or confirmed lensing systems of varying masses, with distorted galaxy images in
arcs of varying sizes around them.
The Dark Energy Survey (DES; @TheDESurvey)— an ongoing international, collaborative effort to produce the largest and deepest contiguous map of the southern sky to date in optical wavelengths — has the potential to add to the roster twice as many strong lenses in the
optical as have ever been discovered across all wavelengths.
July 2016
GeminiFocus
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