J1649+2635: a grand-design spiral with a large double-lobed radio source

We report the discovery of a grand-design spiral galaxy associated with a double-lobed radio source. J1649+2635 (z = 0.0545) is a red spiral galaxy with a prominent bulge that it is associated with a L_{1.4 GHz} ∼ 10²⁴ W Hz^-1 double-lobed radio source that spans almost 100 kpc. J1649+2635 has a black hole mass of M_BH ∼ 3-7 × 10⁸ M_⊙ and SFR ∼ 0.26-2.6 M_⊙ yr^-1. The galaxy hosts an ∼96 kpc diffuse optical halo, which is unprecedented for spiral galaxies. We find that J1649+2635 resides in an overdense environment with a mass of M_dyn = 7.7^{+7.9}_{-4.3} × 10^{13} M_⊙, likely a galaxy group below the detection threshold of the ROSAT All-Sky Survey. We suggest one possible scenario for the association of double-lobed radio emission from J1649+2635 is that the source may be similar to a Seyfert galaxy, located in a denser-than-normal environment. The study of spiral galaxies that host large-scale radio emission is important because although rare in the local Universe, these sources may be more common at high redshifts.