CON-quest: Searching for the most obscured galaxy nuclei

Abstract

Some luminous and ultraluminous infrared galaxies (LIRGs and ULIRGs) host extremely compact and dusty nuclei. The intense infrared radiation arising from warm dust in these sources is prone to excite vibrational levels of molecules such as HCN. This results in emission from the rotational transitions of vibrationally excited HCN (HCN-vib), with the brightest emission found in compact obscured nuclei (CONs). We aim to establish how common CONs are in the local Universe, and whether their prevalence depends on the luminosity or other properties of the host galaxy. We have conducted an Atacama Large Millimeter/submillimeter Array (ALMA) survey of the rotational J=3-2 transition of HCN-vib in a sample of 46 far-infrared luminous galaxies. Compact obscured nuclei are identified in 38 percent of ULIRGs, 21 percent of LIRGs, and 0 percent of lower luminosity galaxies. We find no dependence on the inclination of the host galaxy, but strong evidence of lower IRAS 25 to 60 μm flux density ratios (f25/f60) in CONs compared to the rest of the sample. Furthermore, we find that CONs have stronger silicate features (s9.7μm) but similar PAH equivalent widths (EQW6.2μm) compared to other galaxies. In the local Universe, CONs are primarily found in (U)LIRGs. High resolution continuum observations of the individual nuclei are required to determine if the CON phenomenon is related to the inclinations of the nuclear disks. The lower f25/f60 ratios in CONs as well as the results for the mid-infrared diagnostics investigated are consistent with large dust columns shifting the nuclear radiation to longer wavelengths, making the mid- and far-infrared "photospheres" significantly cooler than the interior regions. To assess the importance of CONs in the context of galaxy evolution, it is necessary to extend this study to higher redshifts where (U)LIRGs are more common.

arXiv comment16 pages, 11 figures, Accepted for publication in Astronomy and Astrophysics

References in corpus (68)

• Coevolution (Or Not) of Supermassive Black Holes and Host Galaxies
• The Demography of Massive Dark Objects in Galaxy Centres
• Herschel Space Observatory - An ESA facility for far-infrared and submillimetre astronomy
• The Photodetector Array Camera and Spectrometer (PACS) on the Herschel Space Observatory
• Secular Evolution and the Formation of Pseudobulges in Disk Galaxies
• Local Supermassive Black Holes, Relics of Active Galactic Nuclei and the X-ray Background
• Astrophysics Source Code Library
• The IRAS Revised Bright Galaxy Sample (RBGS)
• Interpreting the Cosmic Infrared Background: Constraints on the Evolution of the Dust Enshrouded Star Formation Rate
• HyperLEDA. III. The catalogue of extragalactic distances
• Molecular Gas at High Redshift
• Infrared luminosity functions from the Chandra Deep Field South : the Spitzer view on the history of dusty star formation at 0<z<1
• Compaction and Quenching of High-z Galaxies in Cosmological Simulations: Blue and Red Nuggets
• On the Estimation of Confidence Intervals for Binomial Population Proportions in Astronomy: The Simplicity and Superiority of the Bayesian Approach
• The deepest Herschel-PACS far-infrared survey: number counts and infrared luminosity functions from combined PEP/GOODS-H observations
• Mid-IR Galaxy Classification Based on Silicate Obscuration and PAH Equivalent Width
• Fast Molecular Outflows in Luminous Galaxy Mergers: Evidence for Quasar Feedback from Herschel
• The IRAS 1.2 Jy Survey: Redshift Data
• The 0.4 < z < 1.3 star formation history of the Universe as viewed in the far-infrared
• Cold Molecular Outflows in the Local Universe
• Growing supermassive black holes in the late stages of galaxy mergers are heavily obscured
• Mid-Infrared Properties of Nearby Luminous Infrared Galaxies I: Spitzer IRS Spectra for the GOALS Sample
• ALMA observations of molecular tori around massive black holes
• CANDELS+3D-HST: compact SFGs at z~2-3, the progenitors of the first quiescent galaxies
• The power of infrared AGN selection in mergers: a theoretical study
• Herschel/PACS spectroscopy of NGC 4418 and Arp 220: H2O, H2^{18}O, OH, ^{18}OH, O I, HCN and NH3
• Molecular outflows in local ULIRGs: energetics from multi-transition OH analysis
• Are Compton-Thick AGN the Missing Link Between Mergers and Black Hole Growth?
• Dust attenuation, bulge formation and inside-out cessation of star-formation in Star-Forming Main Sequence galaxies at z~2
• Molecular outflows in local galaxies: Method comparison and a role of intermittent AGN driving
• SMA Imaging of CO(3-2) Line and 860 micron Continuum of Arp 220 : Tracing the Spatial Distribution of Luminosity
• Vibrationally Excited HCN in the Luminous Infrared Galaxy NGC 4418
• High resolution observations of HCN and HCO+ J=3-2 in the disk and outflow of Mrk231 -Detection of vibrationally excited HCN in the warped nucleus
• Morphology and Size Differences between Local & High Redshift Luminous Infrared Galaxies
• ALMA Resolves the Nuclear Disks of Arp 220
• P-Cygni Profiles of Molecular Lines toward Arp 220 Nuclei
• Submillimeter Interferometry of the Luminous Infrared Galaxy NGC 4418: A Hidden Hot Nucleus with an Inflow and an Outflow
• High-resolution imaging of the molecular outflows in two mergers: IRAS17208-0014 and NGC1614
• High-Resolution Radio Continuum Measurements of the Nuclear Disks of Arp 220
• Infrared Molecular Starburst Fingerprints in Deeply Obscured (U)LIRG Nuclei
• CANDELS: Elevated Black Hole Growth in the Progenitors of Compact Quiescent Galaxies at z~2
• The Arecibo Arp 220 Spectral Census I: Discovery of the Pre-Biotic Molecule Methanimine and New Cm-wavelength Transitions of Other Molecules
• Fast, Collimated Outflow in the Western Nucleus of Arp 220
• ALMA captures feeding and feedback from the active galactic nucleus in NGC613
• The Mrk 231 molecular outflow as seen in OH
• ALMA 0.1-0.2 arcsec resolution imaging of the NGC 1068 nucleus - compact dense molecular gas emission at the putative AGN location
• ALMA HCN and HCO+ J=3-2 observations of optical Seyfert and luminous infrared galaxies -- Confirmation of elevated HCN-to-HCO+ flux ratios in AGNs --
• Spatially resolved cold molecular outflows in ULIRGs
• The unbearable opaqueness of Arp 220
• The hidden heart of the luminous infrared galaxy IC 860 I. A molecular inflow feeding opaque, extreme nuclear activity
• Central molecular zones in galaxies: 12CO-to-13CO ratios, carbon budget, and X factors
• ALMA 0.02"-resolution observations reveal HCN-abundance-enhanced counter-rotating and outflowing dense molecular gas at the NGC 1068 nucleus
• High-velocity extended molecular outflow in the star-formation dominated luminous infrared galaxy ESO 320-G030
• Resolved Structure of Arp 220 Nuclei at λ~3 mm
• ALMA Astrochemical Observations of the Infrared-Luminous Merger NGC 3256
• ALMA Detection of the Vibrationally Excited HCN J=4-3 Emission Line in the AGN-Hosting Luminous Infrared Galaxy IRAS 20551-4250
• Herschel spectroscopic observations of the compact obscured nucleus in Zw 049.057
• ALMA Spatially-resolved Dense Molecular Gas Survey of Nearby Ultraluminous Infrared Galaxies
• Hidden or missing outflows in highly obscured galaxy nuclei?
• ALMA Multiple-Transition Observations of High Density Molecular Tracers in Ultraluminous Infrared Galaxies
• ALMA Investigation of Vibrationally Excited HCN/HCO+/HNC Emission Lines in the AGN-Hosting Ultraluminous Infrared Galaxy IRAS 20551-4250
• The radio core structure of the luminous infrared galaxy NGC 4418
• The Greenhouse Effect in Buried Galactic Nuclei and the Resonant HCN Vibrational Emission
• The Molecular ISM in the Super Star Clusters of the Starburst NGC 253
• A proto-pseudobulge in ESO 320-G030 fed by a massive molecular inflow driven by a nuclear bar
• A hidden molecular outflow in the LIRG Zw 049.057
• Circumnuclear Structures in Megamaser Host Galaxies
• VV 655 and NGC 4418: Implications of an interaction for the evolution of a LIRG

Cited by in corpus (39)

• A hard X-ray view of Luminous and Ultra-luminous Infrared Galaxies in GOALS: I - AGN obscuration along the merger sequence
• Dust, CO and [CI]: Cross-calibration of molecular gas mass tracers in metal-rich galaxies across cosmic time
• Comprehensive Broadband X-ray and Multiwavelength Study of Active Galactic Nuclei in Local 57 Ultra/luminous Infrared Galaxies Observed with NuSTAR and/or Swift/BAT
• Are local ULIRGs powered by AGN? The sub-kpc view of the 220 GHz continuum. PUMA II
• GOALS-JWST: Resolving the Circumnuclear Gas Dynamics in NGC 7469 in the Mid-Infrared
• A sensitive APEX and ALMA CO(1-0), CO(2-1), CO(3-2), and [CI](1-0) spectral survey of 40 local (U)LIRGs
• The subthermal excitation of the C{\sc i} lines in the molecular gas reservoirs of galaxies: its significance and potential utility
• The Obscured Nucleus and Shocked Environment of VV 114E Revealed by JWST/MIRI Spectroscopy
• Bright Extragalactic ALMA Redshift Survey (BEARS) III: Detailed study of emission lines from 71 Herschel targets
• GOALS-JWST: Pulling Back the Curtain on the AGN and Star Formation in VV 114
• Characterizing Compact 15-33 GHz Radio Continuum Sources in Local U/LIRGs
• Ray-tracing simulations and spectral models of X-ray radiation in dusty media
• A Detailed Look at the Most Obscured Galactic Nuclei in the Mid-Infrared
• The Role of AGN in Luminous Infrared Galaxies from the Multiwavelength Perspective
• SUNRISE: The rich molecular inventory of high-redshift dusty galaxies revealed by broadband spectral line surveys
• Deeply Buried Nuclei in the Infrared-Luminous Galaxies NGC 4418 and Arp 220: I. ALMA Observations at $\lambda =$1.4-0.4 mm and Continuum Analysis
• Extended high-ionization [MgIV] emission tracing widespread shocks in starbursts seen by JWST /NIRSpec
• Discovery of Methanimine Megamasers Toward Compact Obscured Galaxy Nuclei
• The Opaque Heart of the Galaxy IC 860: Analogous Protostellar, Kinematics, Morphology, and Chemistry
• CON-quest II. Spatially and spectrally resolved HCN/HCO+ line ratios in local luminous and ultraluminous infrared galaxies
• Extremely Buried Nucleus of IRAS 17208$-$0014 Observed at Sub-Millimeter and Near-Infrared Wavelengths
• H${}_3^{+}$ absorption and emission in local U/LIRGs with JWST/NIRSpec: Evidence for high H${}_2$ ionization rates
• On unveiling Buried Nuclei with JWST: a technique for hunting the most obscured galaxy nuclei from local to high redshift
• On the thermal structure of the proto-Super Star Cluster 13 in NGC 253
• Warm Molecular Gas in the Central Parsecs of the Buried Nucleus of NGC 4418 Traced with the Fundamental CO Ro-vibrational Absorptions
• A population of Optically Quiescent Quasars from WISE and SDSS
• Revealing the hidden cosmic feast: A z=4.3 galaxy group hosting two optically dark, efficiently star-forming galaxies
• ALMA Sub-arcsec-resolution 183 GHz H2O and Dense Molecular Line Observations of Nearby Ultraluminous Infrared Galaxies
• A spectacular galactic scale magnetohydrodynamic powered wind in ESO 320-G030
• Detection of millimeter-wave coronal emission in a quasar at cosmological distance using microlensing
• Investigating starburst-driven neutrino emission from galaxies in the Great Observatories All-Sky LIRG Survey
• An Imaging and Spectroscopic Exploration of the Dusty Compact Obscured Nucleus Galaxy Zw~049.057
• Systematic Study of the Inner Structure of Molecular Tori in Nearby U/LIRGs using Velocity Decomposition of CO Rovibrational Absorption Lines
• A systematic study on the properties of aromatic and aliphatic hydrocarbon dust in active galactic nuclei with AKARI near-infrared spectroscopy
• Towards an observationally motivated AGN dusty torus model -- II. The roles of density distribution and chemical composition of the dust
• Implication of a galaxy-scale negative feedback by one of the most powerful multi-phase outflows in a hyper-luminous infrared galaxy at the intermediate redshift
• A technique to select the most obscured galaxy nuclei
• High resolution ALMA observations of H${}_2$S in LIRGS (Dense gas and shocks in outflows and CNDs)
• The core starbursts of the galaxy NGC 3628: Radio very long baseline interferometry and X-ray studies