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Title: NuSTAR DETECTION OF THE BLAZAR B2 1023+25 AT REDSHIFT 5.3

B2 1023+25 is an extremely radio-loud quasar at z = 5.3 that was first identified as a likely high-redshift blazar candidate in the SDSS+FIRST quasar catalog. Here, we use the Nuclear Spectroscopic Telescope Array (NuSTAR) to investigate its non-thermal jet emission, whose high-energy component we detected in the hard X-ray energy band. The X-ray flux is ∼ 5.5 x 10{sup -14} erg cm{sup -2} s{sup -1} (5-10 keV) and the photon spectral index is Γ{sub X} ≅ 1.3-1.6. Modeling the full spectral energy distribution, we find that the jet is oriented close to the line of sight, with a viewing angle of ∼3°, and has significant Doppler boosting, with a large bulk Lorentz factor ∼13, which confirms the identification of B2 1023+25 as a blazar. B2 1023+25 is the first object at redshift larger than 5 detected by NuSTAR, demonstrating the ability of NuSTAR to investigate the early X-ray universe and to study extremely active supermassive black holes located at very high redshift.
Authors:
 [1] ; ;  [2] ; ; ;  [3] ; ; ;  [4] ;  [5] ;  [6] ;  [7] ;  [8] ;  [9] ; ; ; ;  [10] ;  [11] ;  [12] more »; « less
  1. Dipartimento di Scienza e Alta Tecnologia, Università dell'Insubria, Via Valleggio 11, I-22100 Como (Italy)
  2. INAF-Osservatorio Astronomico di Brera, via E. Bianchi 46, I-23807 Merate (Italy)
  3. ASI-Science Data Center, via Galileo Galilei, I-00044 Frascati (Italy)
  4. Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States)
  5. Dipartimento di Fisica G. Occhialini, Università di Milano Bicocca, Piazza della Scienza 3, I-20126 Milano (Italy)
  6. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)
  7. Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States)
  8. Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States)
  9. DTU Space-National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark)
  10. Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse 1, D-85748 Garching (Germany)
  11. Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States)
  12. Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States)
Publication Date:
OSTI Identifier:
22270568
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 777; 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; ASTROPHYSICS; BLACK HOLES; COMPUTERIZED SIMULATION; ENERGY SPECTRA; GALAXIES; HARD X RADIATION; JETS; KEV RANGE; QUASARS; RADIOASTRONOMY; RED SHIFT; TELESCOPES; UNIVERSE