Optical, Near-IR, and Sub-mm IFU Observations of the Nearby Dual Active Galactic Nuclei MRK 463

Abstract

We present optical and near-IR Integral Field Unit (IFU) and ALMA band 6 observations of the nearby dual Active Galactic Nuclei (AGN) Mrk 463. At a distance of 210 Mpc, and a nuclear separation of ∼4 kpc, Mrk 463 is an excellent laboratory to study the gas dynamics, star formation processes and supermassive black hole (SMBH) accretion in a late-stage gas-rich major galaxy merger. The IFU observations reveal a complex morphology, including tidal tails, starforming clumps, and emission line regions. The optical data, which map the full extent of the merger, show evidence for a biconical outflow and material outflowing at >600 km s −1 , both associated with the Mrk 463E nucleus, together with large scale gradients likely related to the ongoing galaxy merger. We further find an emission line region ∼11 kpc south of Mrk 463E that is consistent with being photoionized by an AGN. Compared to the current AGN luminosity, the energy budget of the cloud implies a luminosity drop in Mrk 463E by a factor 3-20 over the last 40,000 years. The ALMA observations of 12 CO(2-1) and adjacent 1 mm continuum reveal the presence of ∼10 9 M in molecular gas in the system. The molecular gas shows velocity gradients of ∼800 km/s and ∼400 km/s around the Mrk 463E and 463W nuclei, respectively. We conclude that in this system the infall of ∼100s M /yr of molecular gas is in rough balance with the removal of ionized gas by a biconical outflow being fueled by a relatively small, <0.01% of accretion onto each SMBH.

Prevalence of neutral gas in centres of merging galaxies

“…Information about the gas geometry and kinematics from high spatial resolution ionized and molecular emission line mapping is required to associate the different absorbing components with the emitting regions. For example, multi-wavelength IFU observations of the merger Mrk 463 presented in Treister et al (2018) suggests that while there exists significant reservoir of molecular gas around the double nuclei, only a small fraction of it is feeding the SMBH. More such studies are required to understand the relationship between neutral gas in mergers and AGN activity.…”

The Molecular Gas in the NGC 6240 Merging Galaxy System at the Highest Spatial Resolution

“…In contrast, the CO molecule can be easily excited even in cold environments and is relatively abundant, making it an important tracer of the molecular gas contents of a galaxy. In order to convert from observed 12 CO(2-1) line flux to total molecular gas mass we follow the procedure described by Solomon & Vanden Bout (2005), as done previously by Treister et al (2018). Specifically, the line luminosity is computed from the observed line flux as…”

Active Galactic Nucleus Pairs from the Sloan Digital Sky Survey. III. Chandra X-Ray Observations Unveil Obscured Double Nuclei

“…The first concrete evidence for dual AGNs was a serendipitous discovery by Chandra in NGC 6240 (Komossa et al 2003), a z = 0.02 merging ultra-luminous infrared galaxy (ULIRG), which contains two X-ray nuclei separated by ∼ 1 (∼ 0.7 kpc) in projection. Until recently only a handful of other secure cases were known in the X-rays (e.g., 3C 75 (Hudson et al 2006), Mrk 463 (Bianchi et al 2008;Treister et al 2018), Mrk 266 (Brassington et al 2007Mazzarella et al 2012), and Mrk 739 (Koss et al 2011); but see also Arp 299 (Ballo et al 2004) for a candidate), all of which were confirmed by Chandra.…”