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Title: Discovery of two gravitationally lensed quasars in the Dark Energy Survey

In this study, we present spectroscopic confirmation of two new lensed quasars via data obtained at the 6.5m Magellan/Baade Telescope. The lens candidates have been selected from the Dark Energy Survey (DES) and WISE based on their multi-band photometry and extended morphology in DES images. Images of DES J0115-5244 show two blue point sources at either side of a red galaxy. Our long-slit data confirm that both point sources are images of the same quasar at zs = 1.64. The Einstein Radius estimated from the DES images is 0.51''. DES J2146-0047 is in the area of overlap between DES and the Sloan Digital Sky Survey (SDSS). Two blue components are visible in the DES and SDSS images. The SDSS fiber spectrum shows a quasar component at zs = 2.38 and absorption compatible with Mg II and Fe II at zl = 0.799, which we tentatively associate with the foreground lens galaxy. The long-slit Magellan spectra show that the blue components are resolved images of the same quasar. Furthermore, the Einstein Radius is 0.68'' corresponding to an enclosed mass of 1.6 × 1011 M. Three other candidates were observed and rejected, two being low-redshift pairs of starburst galaxies, and one beingmore » a quasar behind a blue star. These first confirmation results provide an important empirical validation of the data-mining and model-based selection that is being applied to the entire DES dataset.« less
Authors:
 [1]
  1. PAB, Los Angeles, CA (United States). et al.
Publication Date:
OSTI Identifier:
1221334
Report Number(s):
FERMILAB-PUB--15-341-AE
Journal ID: ISSN 1365-2966; arXiv eprint number arXiv:1508.01203
Grant/Contract Number:
AC02-07CH11359
Type:
Accepted Manuscript
Journal Name:
Monthly Notices of the Royal Astronomical Society (Online)
Additional Journal Information:
Journal Name: Monthly Notices of the Royal Astronomical Society (Online); Journal Volume: 454; Journal Issue: 2; Journal ID: ISSN 1365-2966
Publisher:
Royal Astronomical Society
Research Org:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Contributing Orgs:
DES Collaboration
Country of Publication:
United States
Language:
English
Subject:
gravitational lensing: strong; quasars: emission lines; methods: observational; methods: statistical