A Candidate Dual AGN at z=1.175
  The X-ray source CXOXBJ142607.6+353351 (CXOJ1426+35), which was identified in
a 172 ks Chandra image in the Bootes field, shows double-peaked rest-frame
optical/UV emission lines, separated by 0.69" (5.5 kpc) in the spatial
dimension and by 690 km s^-1 in the velocity dimension. The high excitation
lines and emission line ratios indicate both systems are ionized by an AGN
continuum, and the double-peaked profile resembles that of candidate dual AGN.
At a redshift of z=1.175, this source is the highest redshift candidate dual
AGN yet identified. However, many sources have similar emission line profiles
for which other interpretations are favored. We have analyzed the substantial
archival data available in this field, as well as acquired near-infrared (NIR)
adaptive optics (AO) imaging and NIR slit spectroscopy. The X-ray spectrum is
hard, implying a column density of several 10^23 cm^-2. Though heavily
obscured, the source is also one of the brightest in the field, with an
absorption-corrected 2-10 keV luminosity of ~10^45 erg s^-1. Outflows driven by
an accretion disk may produce the double-peaked lines if the central engine
accretes near the Eddington limit. However, we may be seeing the narrow line
regions of two AGN following a galactic merger. While the AO image reveals only
a single source, a second AGN would easily be obscured by the significant
extinction inferred from the X-ray data. Understanding the physical processes
producing the complex emission line profiles seen in CXOJ1426+35 and related
sources is important for interpreting the growing population of dual AGN
candidates.
