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Title: DISCOVERY OF A STRONG LENSING GALAXY EMBEDDED IN A CLUSTER AT z = 1.62

We identify a strong lensing galaxy in the cluster IRC 0218 (also known as XMM-LSS J02182–05102) that is spectroscopically confirmed to be at z = 1.62, making it the highest-redshift strong lens galaxy known. The lens is one of the two brightest cluster galaxies and lenses a background source galaxy into an arc and a counterimage. With Hubble Space Telescope (HST) grism and Keck/LRIS spectroscopy, we measure the source redshift to be z {sub S} = 2.26. Using HST imaging in ACS/F475W, ACS/F814W, WFC3/F125W, and WFC3/F160W, we model the lens mass distribution with an elliptical power-law profile and account for the effects of the cluster halo and nearby galaxies. The Einstein radius is θ{sub E}=0.38{sub −0.01}{sup +0.02} arcsec (3.2{sub −0.1}{sup +0.2} kpc) and the total enclosed mass is M {sub tot}(<θ{sub E})=1.8{sub −0.1}{sup +0.2}×10{sup 11} M{sub ⊙}. We estimate that the cluster environment contributes ∼10% of this total mass. Assuming a Chabrier initial mass function (IMF), the dark matter fraction within θ{sub E} is f{sub DM}{sup Chab}=0.3{sub −0.3}{sup +0.1}, while a Salpeter IMF is marginally inconsistent with the enclosed mass (f{sub DM}{sup Salp}=−0.3{sub −0.5}{sup +0.2}). The total magnification of the source is μ{sub tot}=2.1{sub −0.3}{sup +0.4}. The source has atmore » least one bright compact region offset from the source center. Emission from Lyα and [O III] are likely to probe different regions in the source.« less
Authors:
;  [1] ; ;  [2] ;  [3] ; ;  [4] ;  [5] ;  [6] ;  [7] ;  [8] ;
  1. Institute of Astronomy and Astrophysics, Academia Sinica (ASIAA), P.O. Box 23-141, Taipei 10617, Taiwan (China)
  2. George P. and Cynthia W. Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States)
  3. Astronomy Department, Yale University, New Haven, CT 06511 (United States)
  4. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)
  5. Department of Physics and Astronomy, University of Missouri, 5110 Rockhill Road, Kansas City, MO 64110 (United States)
  6. Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States)
  7. Swinburne University of Technology, Victoria 3122 (Australia)
  8. Department of Physics and Astronomy, The University of Kansas, Malott Room 1082, 1251 Wescoe Hall Drive, Lawrence, KS 66045 (United States)
Publication Date:
OSTI Identifier:
22365660
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 789; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; EMISSION SPECTROSCOPY; GALAXIES; GALAXY CLUSTERS; GRAVITATIONAL LENSES; MASS; MASS DISTRIBUTION; NONLUMINOUS MATTER; PROBES; RED SHIFT; SPACE; TELESCOPES