We report Chandra observations of a double X-ray source in the z = 0.1569 galaxy SDSS J171544.05+600835.7 .
The galaxy was initially identified as a dual AGN candidate based on the double-peaked [ O iii ] \lambda 5007 emission lines , with a line-of-sight velocity separation of 350 km s ^ { -1 } , in its Sloan Digital Sky Survey spectrum .
We used the Kast Spectrograph at Lick Observatory to obtain two longslit spectra of the galaxy at two different position angles , which reveal that the two AGN emission components have not only a velocity offset , but also a projected spatial offset of 1.9 h ^ { -1 } _ { 70 } kpc on the sky . Chandra /ACIS observations of two X-ray sources with the same spatial offset and orientation as the optical emission suggest the galaxy most likely contains Compton-thick dual AGN , although the observations could also be explained by AGN jets .
Deeper X-ray observations that reveal Fe K lines , if present , would distinguish between the two scenarios .
The observations of a double X-ray source in SDSS J171544.05+600835.7 are a proof of concept for a new , systematic detection method that selects promising dual AGN candidates from ground-based spectroscopy that exhibits both velocity and spatial offsets in the AGN emission features .