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Title: DISCOVERY OF A KILOPARSEC-SCALE X-RAY/RADIO JET IN THE z = 4.72 QUASAR GB 1428+4217

Journal Article · · Astrophysical Journal Letters
 [1];  [2]; ; ;  [3]; ;  [4]
  1. National Research Council Research Associate, National Academy of Sciences, Washington, DC 20001 (United States)
  2. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan)
  3. Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States)
  4. Department of Physics, Brandeis University, MS 057, Waltham, MA 02454 (United States)

We report the discovery of a one-sided 3.''6 (24 kpc, projected) long jet in the high-redshift, z = 4.72, quasar GB 1428+4217 in new Chandra X-ray and Very Large Array (VLA) radio observations. This is the highest redshift kiloparsec-scale X-ray/radio jet known. Analysis of archival very long baseline interferometry 2.3 and 8.6 GHz data reveal a faint one-sided jet extending out to {approx}200 pc and aligned to within {approx}30 Degree-Sign of the Chandra/VLA emission. The 3.''6 distant knot is not detected in an archival Hubble Space Telescope image, and its broadband spectral energy distribution is consistent with an origin from inverse Compton scattering of cosmic microwave background photons for the X-rays. Assuming also equipartition between the radiating particles and magnetic field, the implied jet Lorentz factor is Almost-Equal-To 5. This is similar to the other two known z {approx} 4 kpc scale X-ray jet cases and smaller than typically inferred in lower-redshift cases. Although there are still but a few such very high redshift quasar X-ray jets known, for an inverse Compton origin, the present data suggest that they are less relativistic on large scales than their lower-redshift counterparts.

OSTI ID:
22078569
Journal Information:
Astrophysical Journal Letters, Vol. 756, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
Country of Publication:
United States
Language:
English