2018ApJ...869..173R

Among the many varieties of active galactic nuclei (AGNs) known, narrow-line Seyfert 1 (NLSy1) galaxies are a puzzling class, particularly after the discovery of γ-ray emission in a handful of them using observations from the Fermi Gamma-ray Space Telescope. Here, we report the discovery of a rare, large, double-lobed radio source with its radio core associated with an NLSy1 galaxy, SDSS J103024.95+551622.7, at z = 0.435. The lobe separation is 116 kpc which is the second largest known projected size among NLSy1 radio sources. This finding is based on the analysis of 1.4 GHz data from the Faint Images of the Radio Sky at Twenty-centimeters archives. Along with the core and edge-brightened lobes we detected a significant (30%) fraction of clear diffuse emission showing typical back-flow from FR II radio galaxy lobes. For the source, we estimated a jet power of 3 x 10⁴⁴ erg s^–1, suggesting that its jet power is similar to that of classical radio galaxies. Emission from the source is also found to be non-variable both in the optical and mid-infrared bands. Identification of more such sources may help to reveal new modes of AGNs and to understand their role in black hole galaxy evolution.