Paper detail

The Jet-Driven Outflow in the Radio Galaxy SDSS J1517+3353: Implications for Double-Peaked Narrow-Line AGN

We report on the study of an intriguing active galaxy that was selected as a potential multiple supermassive black hole merger in the early-type host SDSS J151709.20+335324.7 (z=0.135). Ground-based SDSS imaging reveals two blue structures on either side of the photometric center of the host galaxy, separated from each other by about 5.7 kpc. The analysis of spatially resolved emission line profiles from a Keck/HIRES spectrum reveal three distinct kinematic subcomponents, one at rest and the other two moving at -350 km/s and 500 km/s with respect to the systemic velocity of the host galaxy. A comparison of imaging and spectral data confirm a strong association between the kinematic components and the spatial knots, which implies a highly disturbed and complex active region in this object. Subsequent VLA radio imaging reveals a clear jet aligned with the emission line gas, confirming that a jet-gas interaction is the best explanation for emission line region. We use the broadband radio measurements to examine the impact of the jet on the ISM of the host galaxy, and find that the energy in the radio lobes can heat a significant fraction of the gas to the virial temperature. Finally, we discuss tests that may help future surveys distinguish between jet-driven kinematics and true black-hole binaries. SDSS J151709.20+335324.7 is a remarkable laboratory for AGN feedback and warrants deeper follow-up study. In the Appendix, we present high-resolution radio imaging of a second AGN with double-peaked [O III] lines, SDSS J112939.78+605742.6, which shows a sub-arcsecond radio jet. If the double-peaked nature of the narrow lines in radio-loud AGN are generally due to radio jet interactions, we suggest that extended radio structure should be expected in most of such systems.