skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: (NuSTARNuSTAR) resolves the first dual AGN above 10 keV in SWIFT J2028.5+2543

Journal Article · · Astrophysical Journal Letters
;  [1];  [2]; ; ; ;  [3];  [4];  [5]; ;  [6];  [7]; ;  [8];  [9];  [10]; ;  [11];  [12];  [13] more »; « less
  1. Institute for Astronomy, Department of Physics, ETH Zurich, Wolfgang-Pauli-Strasse 27, CH-8093 Zurich (Switzerland)
  2. Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States)
  3. Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States)
  4. Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Mail Stop 169-221, Pasadena, CA 91109 (United States)
  5. Núcleo de Astronomía de la Facultad de Ingeniería, Universidad Diego Portales, Av. Ejército 441, Santiago (Chile)
  6. Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22 (Chile)
  7. Center for Relativistic Astrophysics, School of Physics, Georgia Institute of Technology, Atlanta, GA 30332 (United States)
  8. Space Sciences Laboratory, University of California, 7 Gauss Way, Berkeley, CA 94720-7450 (United States)
  9. Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States)
  10. School of Physics and Astronomy, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom)
  11. NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
  12. Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States)
  13. INAF-Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy)

We have discovered heavy obscuration in the dual active galactic nucleus (AGN) in the Swift/Burst Alert Telescope (BAT) source SWIFT J2028.5+2543 using Nuclear Spectroscopic Telescope Array (NuSTAR). While an early XMM-Newton study suggested the emission was mainly from NGC 6921, the superior spatial resolution of NuSTAR above 10 keV resolves the Swift/BAT emission into two sources associated with the nearby galaxies MCG +04-48-002 and NGC 6921 (z = 0.014) with a projected separation of 25.3 kpc (91″). NuSTAR's sensitivity above 10 keV finds both are heavily obscured to Compton-thick levels (N {sub H} ≈ (1–2) × 10{sup 24} cm{sup −2}) and contribute equally to the BAT detection (L{sub 10−50 keV}{sup int} ≈ 6 × 10{sup 42} erg s{sup −1}). The observed luminosity of both sources is severely diminished in the 2–10 keV band (L{sub  2−10 keV}{sup obs}<0.1×L{sub  2−10 keV}{sup int}), illustrating the importance of >10 keV surveys like those with NuSTAR and Swift/BAT. Compared to archival X-ray data, MCG +04-48-002 shows significant variability (>3) between observations. Despite being bright X-ray AGNs, they are difficult to detect using optical emission-line diagnostics because MCG +04-48-002 is identified as a starburst/composite because of the high rates of star formation from a luminous infrared galaxy while NGC 6921 is only classified as a LINER using line detection limits. SWIFT J2028.5+2543 is the first dual AGN resolved above 10 keV and is the second most heavily obscured dual AGN discovered to date in the X-rays other than NGC 6240.

OSTI ID:
22869029
Journal Information:
Astrophysical Journal Letters, Vol. 824, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
Country of Publication:
United States
Language:
English