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Title: 3C 220.3: A radio galaxy lensing a submillimeter galaxy

Herschel Space Observatory photometry and extensive multiwavelength follow-up have revealed that the powerful radio galaxy (PRG) 3C 220.3 at z = 0.685 acts as a gravitational lens for a background submillimeter galaxy (SMG) at z = 2.221. At an observed wavelength of 1 mm, the SMG is lensed into three distinct images. In the observed near infrared, these images are connected by an arc of ∼1''.8 radius forming an Einstein half-ring centered near the radio galaxy. In visible light, only the arc is apparent. 3C 220.3 is the only known instance of strong galaxy-scale lensing by a PRG not located in a galaxy cluster and therefore it offers the potential to probe the dark matter content of the radio galaxy host. Lens modeling rejects a single lens, but two lenses centered on the radio galaxy host A and a companion B, separated by 1''.5, provide a fit consistent with all data and reveal faint candidates for the predicted fourth and fifth images. The model does not require an extended common dark matter halo, consistent with the absence of extended bright X-ray emission on our Chandra image. The projected dark matter fractions within the Einstein radii of A (1''.02) and Bmore » (0''.61) are about 0.4 ± 0.3 and 0.55 ± 0.3. The mass to i-band light ratios of A and B, M/L{sub i}∼8±4 M{sub ⊙} L{sub ⊙}{sup −1}, appear comparable to those of radio-quiet lensing galaxies at the same redshift in the CfA-Arizona Space Telescope LEns Survey, Lenses Structure and Dynamics, and Strong Lenses in the Legacy Survey samples. The lensed SMG is extremely bright with observed f(250 μm) = 440 mJy owing to a magnification factor μ ∼ 10. The SMG spectrum shows luminous, narrow C IV λ1549 Å emission, revealing that the SMG houses a hidden quasar in addition to a violent starburst. Multicolor image reconstruction of the SMG indicates a bipolar morphology of the emitted ultraviolet (UV) light suggestive of cones through which UV light escapes a dust-enshrouded nucleus.« less
Authors:
; ;  [1] ; ; ;  [2] ; ;  [3] ; ; ; ; ;  [4] ;  [5] ;  [6] ;  [7] ;  [8] ;  [9] ; ;  [10]
  1. Astronomisches Institut, Ruhr Universität, Bochum (Germany)
  2. Max-Planck-Institut für Astronomie, Heidelberg (Germany)
  3. Kapteyn Astronomical Institute, University of Groningen (Netherlands)
  4. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)
  5. Max-Planck-Institut für Astrophysik, Garching (Germany)
  6. Imperial College, London (United Kingdom)
  7. University of California, Davis, CA (United States)
  8. Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA (United States)
  9. Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn (Australia)
  10. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA (United States)
Publication Date:
OSTI Identifier:
22365582
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 790; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COSMIC RADIO SOURCES; GALAXY CLUSTERS; GRAVITATIONAL LENSES; IMAGE PROCESSING; MASS; NONLUMINOUS MATTER; PHOTOMETRY; QUASARS; RADIO GALAXIES; RED SHIFT; SIMULATION; SPACE; SPECTRA; TELESCOPES; ULTRAVIOLET RADIATION; VISIBLE RADIATION; X RADIATION