UGC 4211: A Confirmed Dual Active Galactic Nucleus in the Local Universe at 230 pc Nuclear Separation

Abstract

We present multi-wavelength high-spatial resolution (~0.1'', 70 pc) observations of UGC 4211 at z=0.03474, a late-stage major galaxy merger at the closest nuclear separation yet found in near-IR imaging (0.32'', ~230 pc projected separation). Using Hubble Space Telescope/STIS, VLT/MUSE+AO, Keck/OSIRIS+AO spectroscopy, and ALMA observations, we show that the spatial distribution, optical and NIR emission lines, and millimeter continuum emission are all consistent with both nuclei being powered by accreting supermassive black holes (SMBHs). Our data, combined with common black hole mass prescriptions, suggests that both SMBHs have similar masses, log MBH~8.1 (south) and log MBH~8.3 (north), respectively. The projected separation of 230 pc (~6X the black hole sphere of influence) represents the closest-separation dual AGN studied to date with multi-wavelength resolved spectroscopy and shows the potential of nuclear (<50 pc) continuum observations with ALMA to discover hidden growing SMBH pairs. While the exact occurrence rate of close-separation dual AGN is not yet known, it may be surprisingly high, given that UGC 4211 was found within a small, volume-limited sample of nearby hard X-ray detected AGN. Observations of dual SMBH binaries in the sub-kpc regime at the final stages of dynamical friction provide important constraints for future gravitational wave observatories.

arXiv comment19 pages, 7 figures, 2 tables, published in ApJL

References in corpus (75)

• Astropy: A Community Python Package for Astronomy
• Observation of Gravitational Waves from a Binary Black Hole Merger
• The NumPy array: a structure for efficient numerical computation
• Coevolution (Or Not) of Supermassive Black Holes and Host Galaxies
• The Host Galaxies and Classification of Active Galactic Nuclei
• Improving the full spectrum fitting method: accurate convolution with Gauss-Hermite functions
• Adaptive spatial binning of integral-field spectroscopic data using Voronoi tessellations
• The MUSE second-generation VLT instrument
• Automated data reduction workflows for astronomy
• The 70 Month Swift-BAT All-Sky Hard X-Ray Survey
• BAT AGN Spectroscopic Survey - V. X-ray properties of the Swift/BAT 70-month AGN catalog
• The International Pulsar Timing Array: First Data Release
• A Compact Supermassive Binary Black Hole System
• Ejection of hypervelocity stars by the (binary) black hole(s) in the Galactic center
• BAT AGN Spectroscopic Survey I: Spectral Measurements, Derived Quantities, and AGN Demographics
• Galaxy-Wide Shocks in Late-Merger Stage Luminous Infrared Galaxies
• Understanding Dual AGN Activation in the Nearby Universe
• Hydrodynamics of circumbinary accretion: Angular momentum transfer and binary orbital evolution
• Galaxy Zoo DECaLS: Detailed Visual Morphology Measurements from Volunteers and Deep Learning for 314,000 Galaxies
• A Search for Binary Active Galactic Nuclei: Double-Peaked [OIII] AGN in the Sloan Digital Sky Survey
• Merging and Clustering of the Swift BAT AGN Sample
• Observability of Dual Active Galactic Nuclei in Merging Galaxies
• The power of infrared AGN selection in mergers: a theoretical study
• Improved and Quality-assessed Emission and Absorption Line measurements in Sloan Digital Sky Survey galaxies
• Type 2 Active Galactic Nuclei with Double-Peaked [OIII] Lines. II. Single AGNs with Complex Narrow-Line Region Kinematics are More Common than Binary AGNs
• The Galaxy Zoo survey for giant AGN-ionized clouds: past and present black-hole accretion events
• Host Galaxy Properties of the Swift BAT Ultra Hard X-ray Selected AGN
• BASS XXII: The BASS DR2 AGN Catalog and Data
• Active Galactic Nucleus Pairs from the Sloan Digital Sky Survey. I. The Frequency on ~ 5-100 kpc Scales
• The Nature of Double-Peaked [O III] Active Galactic Nuclei
• Chandra Discovery of a Binary Active Galactic Nucleus in Mrk 739
• Origin and properties of dual and offset active galactic nuclei in a cosmological simulation at z=2
• A population of luminous accreting black holes with hidden mergers
• A Radio Census of Binary Supermassive Black Holes
• A New Population of Compton-Thick AGN Identified Using the Spectral Curvature Above 10 keV
• Single Sources in the Low-Frequency Gravitational Wave Sky: properties and time to detection by pulsar timing arrays
• Mergers in Double-Peaked [O III] Active Galactic Nuclei
• A Close Nuclear Black Hole Pair in the Spiral Galaxy NGC 3393
• BAT AGN Spectroscopic Survey - IV: Near-Infrared Coronal Lines, Hidden Broad Lines, and Correlation with Hard X-ray Emission
• Go with the Flow: Understanding Inflow Mechanisms in Galaxy Collisions
• Post-Newtonian evolution of massive black hole triplets in galactic nuclei -- III. A robust lower limit to the nHz stochastic background of gravitational waves
• A hard X-ray view of Luminous and Ultra-luminous Infrared Galaxies in GOALS: I - AGN obscuration along the merger sequence
• BAT AGN Spectroscopic Survey-XX: Molecular Gas in Nearby Hard X-ray Selected AGN Galaxies
• Herschel far-infrared photometry of the Swift Burst Alert Telescope active galactic nuclei sample of the local universe - III. Global star-forming properties and the lack of a connection to nuclear activity
• Massive black hole evolution models confronting the n-Hz amplitude of the stochastic gravitational wave background
• The X-Shooter Spectral Library (XSL): Data Release 2
• Polar Dust, Nuclear Obscuration and IR SED Diversity in Type-1 AGNs
• Broadband Observations of the Compton-thick Nucleus of NGC 3393
• Parsec-Scale Radio Structure of the Double Active Nucleus of NGC 6240
• BAT AGN Spectroscopic Survey XXI: The Data Release 2 Overview
• Discovery of a close-separation binary quasar at the heart of a z~0.2 merging galaxy and its implications for low-frequency gravitational waves
• BASS XXXII: Studying the Nuclear Mm-wave Continuum Emission of AGNs with ALMA at Scales $\lesssim$ 100-200 pc
• A hidden population of high-redshift double quasars unveiled by astrometry
• The properties of the AGN torus as revealed from a set of unbiased NuSTAR observations
• BASS XXVI: DR2 Host Galaxy Stellar Velocity Dispersions
• NuSTAR Resolves the First Dual AGN above 10 keV in SWIFT J2028.5+2543
• BAT AGN Spectroscopic Survey -- XV: The High Frequency Radio Cores of Ultra-hard X-ray Selected AGN
• Studying Faint Ultra Hard X-ray Emission from AGN in GOALS LIRGs with Swift BAT
• A Catalog of 220 Offset and Dual AGNs: Increased AGN Activation in Major Mergers and Separations under 4 kpc
• SDSS-IV MaNGA: Galaxy Pair Fraction and Correlated Active Galactic Nuclei
• The Molecular Gas in the NGC 6240 Merging Galaxy System at the Highest Spatial Resolution
• The Keck/OSIRIS Nearby AGN Survey (KONA) I. The Nuclear K-band Properties of Nearby AGN
• Mass of the Southern Black Hole in NGC 6240 from Laser Guide Star Adaptive Optics
• BASS XXVIII: Near-infrared Data Release 2, High-Ionization and Broad Lines in Active Galactic Nuclei
• A large sample of Kohonen selected E+A (post-starburst) galaxies from the Sloan Digital Sky Survey
• Sensitivity of present and future detectors across the black-hole binary gravitational wave spectrum
• Spatially Offset Active Galactic Nuclei. II: Triggering in Galaxy Mergers
• A Hubble Space Telescope Imaging Survey of Low-Redshift Swift-BAT Active Galaxies
• A Bayesian Analysis of SDSS J0914+0853, a Low-Mass Dual AGN Candidate
• Optical and X-ray discovery of the changing-look AGN IRAS23226-3843 showing extremely broad and double-peaked Balmer profiles
• Optical, near-IR and sub-mm IFU Observations of the nearby dual AGN Mrk 463
• On the Prevalence of Super-Massive Black Holes over Cosmic Time
• Unveiling the hosts of parsec-scale massive black hole binaries: morphology and electromagnetic signatures
• Detailed accretion history of the supermassive black hole in NGC 5972 over the past $\gtrsim$10${}^4$ years through the extended emission line region
• The Evolution of Stellar Velocity Dispersion During Dissipationless Galaxy Mergers

Cited by in corpus (16)

• A Tight Correlation Between Millimeter and X-ray Emission in Accreting Massive Black Holes from <100 Milliarcsecond-resolution ALMA Observations
• GA-NIFS: High number of dual active galactic nuclei at z~3
• Refining the 2022 OJ 287 impact flare arrival epoch
• Reliable Identification of Binary Supermassive Black Holes from Rubin Observatory Time-Domain Monitoring
• A Big Red Dot: Scattered light, host galaxy signatures and multi-phase gas flows in a luminous, heavily reddened quasar at cosmic noon
• Automated Detection of Double Nuclei Galaxies using GOTHIC and the Discovery of a Large Sample of Dual AGN
• Euclid: Early Release Observations of diffuse stellar structures and globular clusters as probes of the mass assembly of galaxies in the Dorado group
• Varstrometry Selected Radio-Loud Candidates of Dual and Off-Nucleus Quasars at Sub-kpc Scales
• A Dual Active Black Hole Candidate with Mass Ratio ~7:1 in a Disk Galaxy
• AT2020ohl: its nature and probable implications
• Probing Picohertz Gravitational Waves with Pulsars
• Extended coronal line emission and new clues to a possible dual AGN in the merger J1356+1026
• BASS. XLIV. Morphological preferences of local hard X-ray selected AGN
• Milliarcsecond astrometric oscillations in active galactic nuclei as a precursor of multi-messenger gravitational wave events
• Probing Heavily Obscured AGN in Major Galaxy Mergers Using the mm-X-ray Correlation
• Fast, dust-poor outflows in the local candidate dual AGN MCG-03-34-64 observed with VLT/ERIS