2015MNRAS.446.4176M

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 L1.4GHz ∼ 10²⁴ W/ Hz double-lobed radio source that spans almost 100 kpc. J1649+2635 has a black hole mass of MBH ∼ 3-7x10⁸ M_☉ and SFR ∼ 0.26-2.6 M_☉/yr. 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.