Discovery of a binary AGN in the ultraluminous infrared galaxy NGC 6240 using Chandra

Abstract

Ultraluminous infrared galaxies (ULIRGs) are outstanding due to their huge luminosity output in the infrared, which is predominantly powered by super starbursts and/or hidden active galactic nuclei (AGN). NGC 6240 is one of the nearest ULIRGs and is considered a key representative of its class. Here, we report the first high-resolution imaging spectroscopy of NGC 6240 in X-rays. The observation, performed with the ACIS-S detector aboard the Chandra X-ray observatory, led to the discovery of two hard nuclei, coincident with the optical-IR nuclei of NGC 6240. The AGN character of both nuclei is revealed by the detection of absorbed hard, luminous X-ray emission and two strong neutral Fe_K_alpha lines. In addition, extended X-ray emission components are present, changing their rich structure in dependence of energy. The close correlation of the extended emission with the optical Halpha emission of NGC 6240, in combination with the softness of its spectrum, clearly indicates its relation to starburst-driven superwind activity.

arXiv commentApJ Letters in press, 7 colour figures included; preprint and related papers on NGC 6240 also available at http://www.xray.mpe.mpg.de/~skomossa/

References in corpus (11)

• What Powers Ultra-luminous IRAS Galaxies?
• Dusty star forming galaxies at high redshift
• X-ray spectral imaging and Doppler mapping of Cassiopeia A
• Gas Dynamics in the Luminous Merger NGC 6240
• A Chandra X-ray Study of NGC 1068 - I. Observations of Extended Emission
• Stellar Dynamics and the implications on the merger evolution in NGC6240
• ASCA spectroscopy of the luminous infrared galaxy NGC6240: X-ray emission from a starburst and a buried active nucleus
• The Radio Emission from the Ultra-Luminous Far-Infrared Galaxy NGC 6240
• The `Great Debate': The Case for AGNs
• The Soft X-ray Spectrum of Scattering--Dominated AGN
• RXTE observation of NGC 6240: a search for the obscured active nucleus

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• A High Fraction of Double-peaked Narrow Emission Lines in Powerful Active Galactic Nuclei
• HST and LAMOST discover a dual active galactic nucleus in J0038+4128
• Recurrent Neutrino Emission from Supermassive Black Hole Mergers
• Microlensing of Sub-parsec Massive Binary Black Holes in Lensed QSOs: Light Curves and Size-Wavelength Relation
• A practical guide to the massive black hole cosmic history
• Searching for Dual Active Galactic Nuclei
• Compact object mergers: Observations of supermassive binary black holes and stellar tidal disruption events
• The origin of double-peak emission-line galaxies: rotating discs, bars or galaxy mergers?
• A single radio-emitting nucleus in the dual AGN candidate NGC 5515
• A Multi-wavelength Study of the Dual Nuclei in Mrk 212
• Merging of a massive black hole binary II
• Binary Black Holes, Gas Sloshing, and Cold Fronts in the X-ray Halo Hosting 4C+37.11
• The Role of Nuclear Star Clusters in Enhancing Supermassive Black Hole Feeding Rates During Galaxy Mergers
• Chandra Observations of the X-ray Point Source Population in NGC 4636
• Luminosity Ratio between [O IV] 25.89 um Line and Nuclear Continuum 12 um as Diagnostic for "Buried" AGN
• On the X-ray Properties of OH Megamaser Sources: Chandra Snapshot Observations
• Binary Black Holes at the Core of Galaxy Clusters
• Constraints on Two Active Galactic Nuclei in the Merger Remnant COSMOS J100043.15+020637.2
• Kinematically Identified Recoiling Supermassive Black Hole Candidates in SDSS QSOs with z $<$ 0.25
• The Structure of Active Merger Remnant NGC 6240 from IRAC Observations
• Tracing the merger-driven evolution of active galaxies using the CJF sample
• Near- to Mid- Infrared Imaging and Spectroscopy of Two Buried AGNs of the Nearby Merging Galaxy NGC 6240 with Subaru/IRCS+AO and GTC/CanariCam
• A 3.8yr optical quasi-periodic oscillations in blue quasar SDSS J132144+033055 through combined light curves from CSS and ZTF
• How to Fuel an AGN: Mapping Circumnuclear Gas in NGC 6240 with ALMA
• NGC 6240 Supermassive Black Hole Binary dynamical evolution based on Chandra data
• Dark Matter Signatures of Supermassive Black Hole Binaries
• Merging timescale for supermassive black hole binary in interacting galaxy NGC 6240
• Discovery of the disturbed radio morphology in the interacting binary quasar FIRST J164311.3+315618
• Probing black hole accretion in quasar pairs at high redshift
• Characterisation of a candidate dual AGN
• Differential Interferometric Signatures of Close Binaries of Supermassive Black Holes in Active Galactic Nuclei
• Metal-Enriched Outflows in the Ultra-Luminous infrared Quasar Q1321+058
• XMM-Newton view of galaxy pairs: activation of quiescent black holes?
• The merger Seyfert galaxy Arp 220. Line and continuum absorption and emission
• Simulations of recoiling black holes: adaptive mesh refinement and radiative transfer
• XMM-Newton Detection of a Compton-thick AGN in the 1-Jy ULIRG/LINER F04103-2838
• X-ray Absorption and Optical Extinction in the Partially Obscured Seyfert Nucleus in Mrk 1393
• Tracing the Ionization Structure of the Shocked Filaments of NGC 6240
• CON-quest II. Spatially and spectrally resolved HCN/HCO+ line ratios in local luminous and ultraluminous infrared galaxies
• 2MASX J00423991+3017515: An offset active galactic nucleus in an interacting system
• Quantum gravity phenomenology at the dawn of the multi-messenger era -- A review
• Tracing the Evolution of Ultraluminous Infrared Galaxies into Radio Galaxies with Low Frequency Radio Observations
• Comparing Chandra and SIRTF Observations for Obscured Starbursts and AGN at High Redshift
• Recoiling Supermassive Black Holes in Spin-flip Radio Galaxies
• Bimodal AGNs in Bimodal Galaxies
• High-energy signatures of binary systems of supermassive black holes
• Automated Detection of Double Nuclei Galaxies using GOTHIC and the Discovery of a Large Sample of Dual AGN
• Hard X-ray Irradiation Potentially Drives Negative AGN Feedback by Altering Molecular Gas Properties
• Subaru Infrared Adaptive Optics-assisted High-spatial-resolution Imaging Search for Luminous Dual Active Galactic Nuclei in Nearby Ultraluminous Infrared Galaxies
• A SysTematic seaRch fOr Dual Agns in meRgINg Galaxies (ASTRO-DARING) III: results from the SDSS spectroscopic surveys
• X-ray Clusters of Galaxies as Cosmological Tools
• Probing the Delay Time of Supermassive Black Hole Binary Mergers With Gravitational Waves
• Gravitational Wave Heating of Stars and Accretion Disks
• Central X-ray point-sources found to be abundant in low-mass, late-type galaxies predicted to contain an intermediate-mass black hole
• Near-IR observations of the HE0450-2958 system: discovery of a second AGN?
• Unveiling the radio counterparts of two binary AGN candidates: J1108+0659 and J1131-0204
• The Host Galaxies and Narrow Line Regions of Four Double-Peaked [OIII] AGN
• Evolution of Massive Black Hole Binaries in Collisionally Relaxed Nuclear Star Clusters -- Impact of Mass Segregation
• The quasar SDSS J142507.32+323137.4 : dual AGNs?
• Jet-powered Outflows in Supermassive Black Hole Binary Candidate SDSS J1048+0055
• Dynamical processes in galaxy centers
• Resolving Complex Inner X-ray Structure of the Gravitationaly Lensed AGN MGB2016+112
• The study of Seyfert 2 galaxies with and without infrared broad lines
• The Host Galaxy of the Recoiling Black Hole Candidate in 3C 186: An Old Major Merger Remnant at the Center of a z=1 Cluster
• The JWST/NIRSpec view of the nuclear region in the prototypical merging galaxy NGC 6240
• BASS. XLIX. Characterization of highly luminous and obscured AGNs: local X-ray and [NeV]$\lambda$3426 emission in comparison with the high-redshift Universe
• A Multi-wavelength Study of the Host Environment of SMBHB 4C+37.11
• A candidate of binary black hole system in AGN with broad Balmer emission lines having quite different line widths
• Hydrodynamical Simulations of the Triggering of Nuclear Activities by Minor Mergers of Galaxies
• Observations of [OI]63micron line emission in main-sequence galaxies at z~1.5
• Orbit Tomography of Binary Supermassive Black Holes with Very Long Baseline Interferometry
• The origin of the near-IR line emission from molecular, low and high ionization gas in the inner kiloparsec of NGC6240
• Menus for Feeding Black Holes
• Unusual Hard X-ray Flares Caught in NICER Monitoring of the Binary Supermassive Black Hole Candidate AT2019cuk/Tick Tock/SDSS J1430+2303
• Radio Emission of Nearby Early-type Galaxies at Low and Very-Low Radio Luminosity Range
• A SysTematic seaRch fOr Dual Agns in meRgINg Galaxies (ASTRO-DARING) II: first results from long-slit spectroscopic observations
• Dissecting the Extended X-ray Emission in the Merging Pair NGC 6240
• Millimeter line observations toward four local galaxies
• A catalogue of candidate milli-parsec separation massive black hole binaries from long term optical photometric monitoring
• Lyman edges in supermassive black hole binaries
• Constraining cloud parameters using high density gas tracers in galaxies
• Finding binary active galactic nuclei candidates by the centroid shift in imaging surveys II. Testing the method with SDSS J233635.75-010733.7
• Orbit classification in a pseudo-Newtonian Copenhagen problem with Schwarzschild-like primaries
• Metallicity in the merger Seyfert galaxy NGC 6240
• Relics of Galaxy Merging: Observational Predictions for a Wandering Massive Black Hole and Accompanying Star Cluster in the Halo of M31
• Circumnuclear Shock and Starburst in NGC 6240: Near-IR Imaging and Spectroscopy with Adaptive Optics
• The X-shaped radio galaxy J0725+5835 is associated with an AGN pair
• Multi-wavelength observations of the triple-peaked AGN Mrk 622
• Chaotic orbits in a 3D galactic dynamical model with a double nucleus
• QSO pairs {\it across} Active galaxies: Evidence of Blueshifts?
• Unravelling the nature of the dual AGN in the galaxy pair system IRAS 05589+2828 and 2MASX J06021107+2828382
• Detection of the Fe K lines from the binary AGN in 4C+37.11
• Periodic variability of the z=2.0 quasar QSO B1312+7837
• The Messy Nature of Fiber Spectra: Star-Quasar Pairs Masquerading as Dual Type 1 AGNs
• Molecular Gas in the Nuclear Region of NGC 6240
• High-Resolution Imaging of Water Maser Emission in the active galaxies NGC 6240 and M51
• Modelling Mechanical Heating in Star-Forming Galaxies: CO and 13CO Line Ratios as Sensitive Probes
• Role of AGNs in the Luminous Infrared Galaxy phase since z ~ 3
• XMM-Newton Observations of Three Interacting Luminous Infrared Galaxies
• Discovery of a z=0.65 Post-Starburst BAL Quasar in the DES Supernova Fields
• Two Epochs of Very Large Array Observations of Water Maser Emission in the active galaxy NGC 6240
• From binary to singular: the AGN PSO J334.2028+1.4075 under the high-resolution scope
• Effects of eccentricity on accreting binary black holes: MHD simulations in full GR reveal novel periodicities in jet power and synchrotron spectra
• Three Spectacular HII-buried-AGN Galaxies from SDSS
• Dynamical evolution timescales for the triple supermassive black hole system in NGC 6240
• Tidal disruptions in circumbinary disks. II: Observational signatures in the reverberation spectra
• Outflowing shocked gas dominates the NIR H${}_2$ emission from the dual AGN NGC6240
• A Dual Active Black Hole Candidate with Mass Ratio ~7:1 in a Disk Galaxy
• A meeting at z~3: Young massive galaxies and an AGN within 30kpc of the luminous QSO LBQS0302-0019
• Tracing the Evolution of SMBHs and Stellar Objects in Galaxy Mergers: An Multi-mass Direct N-body Model
• Time Evolution of Mg II in SDSS J2320+0024: Implications for a Subparsec Binary Supermassive Black Hole System
• Ionized regions in the central arcsecond of NGC 1068. YJHK spatially resolved spectroscopy
• Search for Quasar Pairs with $Gaia$ Astrometric Data. I. Method and Candidates
• Swift, NuStar and XMM-Newton observations of the NLS1 galaxy RX J2317.8-4422 in an extreme X-ray low flux state
• Effects of a Supermassive Black Hole Binary on a Nuclear Gas Disk
• Kinematic properties of the dual AGN system J0038+4128 based on long-slit spectroscopy
• Extended coronal line emission and new clues to a possible dual AGN in the merger J1356+1026
• Evolution of Stellar Orbits Around Merging Massive Black-Hole Binary
• GRB011211: An alternative interpretation of the optical and X-ray spectra in terms of blueshifts
• AGN in the ULIRG HE 0435-5304
• Molecular gas content and high excitation of a massive main-sequence galaxy at z = 3
• Keck/ESI Long-slit Spectroscopy of SBS 1421+511: A Recoiling Quasar Nucleus in An Active Galaxy Pair?
• Unveiling multiple AGN activity in galaxy mergers
• Line Shapes Emitted from Spiral Structures around Symmetric Orbits of Supermassive Binary Black Holes
• RXCJ1111.6+4050 galaxy cluster: the observational evidence of a transitional fossil group
• The merging/AGN connection: A case for 3D spectroscopy
• Searching for Black Holes in Space - the key role of X-ray observations
• Mapping the diffuse interstellar bands $\lambda$5780 and $\lambda$6284 in the luminous infrared galaxy merger NGC 6240
• A restless supermassive black hole in the galaxy J0437+2456
• Revisiting dual AGN candidates with spatially resolved LBT spectroscopy -- The impact of spillover light contamination
• The most massive galaxies with large depleted cores: structural parameter relations and black hole masses
• Nuclear activity in galaxies driven by binary supermassive black holes
• Fast, dust-poor outflows in the local candidate dual AGN MCG-03-34-64 observed with VLT/ERIS
• Investigating the Bulge Morphology of Dual AGN Host Galaxies from the GOTHIC survey
• Mass flow in the circumbinary disk with gap around supermassive binary black holes
• X-ray and CO-Derived Column Densities in AGN: A Study of Obscuration Properties in CTAGN and Non-CTAGN
• H2 MAGIE: H2 as a Major Agent to Galaxy Interaction and Evolution
• The core starbursts of the galaxy NGC 3628: Radio very long baseline interferometry and X-ray studies
• A pair of UV nuclei or a compact star forming region near the active nucleus in Mrk~766?
• Merging of unequal mass binary black holes in non-axisymmetric galactic nuclei
• A concept for the X-ray telescope system with an angular-resolution booster
• Prospects for probing supermassive binary black holes in strongly lensed active galactic nuclei via microlensing effects
• AGN jets and a fanciful trio of black holes in the Abell 85 Brightest Cluster Galaxy