2015ApJ...807..149K

We present new Nuclear Spectroscopic Telescope Array (NuSTAR) and Chandra observations of NGC 3393, a galaxy reported to host the smallest separation dual active galactic nuclei (AGN) resolved in the X-rays. While past results suggested a 150 pc separation dual AGN, three times deeper Chandra imaging, combined with adaptive optics and radio imaging suggest a single, heavily obscured, radio-bright AGN. Using Very Large Array and Very Long Baseline Array data, we find an AGN with a two-sided jet rather than a dual AGN and that the hard X-ray, UV, optical, near-infrared, and radio emission are all from a single point source with a radius <0." 2. We find that the previously reported dual AGN is most likely a spurious detection resulting from the low number of X-ray counts (<160) at 6-7 keV and Gaussian smoothing of the data on scales much smaller than the point-spread function (PSF) (0." 25 versus 0." 80 FWHM). We show that statistical noise in a single Chandra PSF generates spurious dual peaks of the same separation (0." 55±0." 07 versus 0." 6) and flux ratio (39%±9% versus 32% counts) as the purported dual AGN. With NuSTAR, we measure a Compton-thick source () with a large torus half-opening angle, which we postulate results from feedback from strong radio jets. This AGN shows a 2-10 keV intrinsic-to-observed flux ratio of ( versus). Using simulations, we find that even the deepest Chandra observations would severely underestimate the intrinsic luminosity of NGC 3393 above, but would detect an unobscured AGN of this luminosity out to high redshift ().