The Complex Gaseous and Stellar environments of the nearby dual AGN Mrk 739

Abstract: We present Integral Field Spectroscopic (IFS) observations of the nearby ($z\sim0.03$) dual Active Galactic Nuclei (AGN) Mrk 739, whose projected nuclear separation is $\sim$3.4~kpc, obtained with the Multi Unit Spectroscopic Explorer (MUSE) at the Very Large Telescope (VLT). We find that the galaxy has an extended AGN-ionized emission-line region extending up to $\sim 20$ kpc away from the nuclei, while star-forming regions are more centrally concentrated within 2 - 3 kpc. We model the kinematics of the ionized gas surrounding the East nucleus using a circular disk profile, resulting in a peak velocity of $237^{+26}_{-28}$ km s$^{-1}$ at a distance of $\sim 1.2$ kpc. The enclosed dynamical mass within 1.2 kpc is $\log M(M_{\odot})=10.20\pm0.06$, $\sim$1,000 times larger than the estimated supermassive black hole (SMBH) mass of Mrk 739E. The morphology and dynamics of the system are consistent with an early stage of the collision, where the foreground galaxy (Mrk 739W) is a young star-forming galaxy in an ongoing first passage with its background companion (Mrk 739E). Since the SMBH in Mrk 739W does not show evidence of being rapidly accreting, we claim that the northern spiral arms of Mrk 739W are ionized by the nuclear activity of Mrk 739E.