J1649+2635: A Grand-Design Spiral with a Large Double-Lobed Radio Source

Abstract

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\mathrm{GHz}}\sim$10${}^{24}$WHz${}^{-1}$ double-lobed radio source that spans almost 100kpc. J1649+2635 has a black hole mass of M${}_{\mathrm{BH}}\sim$ 3--7 $\times$ 10${}^8$M${}_{\odot }$ and SFR$\sim$ 0.26 -- 2.6M${}_{\odot }$year${}^{-1}$. The galaxy hosts a $\sim$96kpc diffuse optical halo, which is unprecedented for spiral galaxies. We find that J1649+2635 resides in an overdense environment with a mass of M${}_{dyn}=7.7_{-4.3}^{+7.9}\times 10^{13}$M${}_{\odot }$, 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.

11 pages, 9 figures, Accepted for publication in MNRAS