JWST MIRI observations of 634 galaxies at 0.2<z<2 yield IR luminosity functions with faint-end slope α≈0.147, implying lower dust-obscured SFRD than previous ALMA/Herschel/Spitzer studies.
Obscured Active Galactic Nuclei
9 Pith papers cite this work. Polarity classification is still indexing.
abstract
Active Galactic Nuclei (AGN) are powered by the accretion of material onto a supermassive black hole (SMBH), and are among the most luminous objects in the Universe. However, the huge radiative power of most AGN cannot be seen directly, as the accretion is "hidden" behind gas and dust that absorbs many of the characteristic observational signatures. This obscuration presents an important challenge for uncovering the complete AGN population and understanding the cosmic evolution of SMBHs. In this review we describe a broad range of multi-wavelength techniques that are currently employed to identify obscured AGN, and assess the reliability and completeness of each technique. We follow with a discussion of the demographics of obscured AGN activity, explore the nature and physical scales of the obscuring material, and assess the implications of obscured AGN for observational cosmology. We conclude with an outline of the prospects for future progress from both observations and theoretical models, and highlight some of the key outstanding questions.
years
2026 9verdicts
UNVERDICTED 9representative citing papers
Presents a public spectroscopic atlas of 887 Southern broad-line AGNs at low redshift, including continuum decompositions and emission-line fits.
LISA observations of inspiraling stellar-mass BBHs around SMBHs can achieve relative uncertainties of 10^{-5} for SMBH mass and a few percent for spin in high-SNR cases.
Using ray-tracing simulations and simulation-based inference, the authors construct an AGN population that reproduces the cosmic X-ray background, number counts, and absorption properties, deriving an intrinsic Compton-thick fraction of 40±3%.
X-ray analysis of 94 FIR-selected AGNs at z=0.07-5 shows rising obscured fraction with redshift, soft excess in 10 sources, and a luminosity-dependent covering factor correlation supporting the receding torus model.
Multi-scale radio observations of 15 local U/LIRGs decompose emission to show nuclear components contribute ~50% on average while diffuse SF-related emission dominates ~80% of total power, with radio excess linked to AGN rather than boosted star formation.
VLA radio-selected LLAGN show 84% optical, 63% X-ray, and 13% infrared detection rates, with black holes ~0.7 dex smaller, accretion rates ~4.2 dex lower, and host galaxies ~0.3 dex lower in stellar mass with ~0.5 dex suppressed star formation than Swift-BAT AGN.
SKAO continuum surveys will detect radio emission from JWST AGN and LRDs and distinguish between Compton-thick absorption, intrinsically weak accretion, and dense gas cocoon scenarios.
Overview chapter summarizing traditional orientation-based and radiation-regulated unification models for AGN, including evolutionary aspects and changing-look AGN.
citing papers explorer
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MEGA and SMILES Find Fewer Dusty Galaxies than Expected at Cosmic Noon
JWST MIRI observations of 634 galaxies at 0.2<z<2 yield IR luminosity functions with faint-end slope α≈0.147, implying lower dust-obscured SFRD than previous ALMA/Herschel/Spitzer studies.
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OzSSy1: The Australian Southern Seyfert-1 Spectroscopic Atlas and Catalogue at z < 0.1
Presents a public spectroscopic atlas of 887 Southern broad-line AGNs at low redshift, including continuum decompositions and emission-line fits.
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Constraining Kerr supermassive black hole properties using gravitational waves from inspiraling stellar-mass binary black holes
LISA observations of inspiraling stellar-mass BBHs around SMBHs can achieve relative uncertainties of 10^{-5} for SMBH mass and a few percent for spin in high-SNR cases.
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Population synthesis of active galactic nuclei based on the radiation-regulated unification model
Using ray-tracing simulations and simulation-based inference, the authors construct an AGN population that reproduces the cosmic X-ray background, number counts, and absorption properties, deriving an intrinsic Compton-thick fraction of 40±3%.
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The Lockman-SpReSO Project: A Deep X-ray Spectral View of a FIR-selected AGN Population
X-ray analysis of 94 FIR-selected AGNs at z=0.07-5 shows rising obscured fraction with redshift, soft excess in 10 sources, and a luminosity-dependent covering factor correlation supporting the receding torus model.
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The PARADIGM Project II: Characterising Nuclear and Diffuse Radio Components in Local U/LIRGs
Multi-scale radio observations of 15 local U/LIRGs decompose emission to show nuclear components contribute ~50% on average while diffuse SF-related emission dominates ~80% of total power, with radio excess linked to AGN rather than boosted star formation.
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Nuclear Activity and Host Galaxy Properties of Low-Luminosity AGN Identified from VLA Observations
VLA radio-selected LLAGN show 84% optical, 63% X-ray, and 13% infrared detection rates, with black holes ~0.7 dex smaller, accretion rates ~4.2 dex lower, and host galaxies ~0.3 dex lower in stellar mass with ~0.5 dex suppressed star formation than Swift-BAT AGN.
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Unveil the nature of JWST-AGN and Little Red Dots with SKAO continuum surveys
SKAO continuum surveys will detect radio emission from JWST AGN and LRDs and distinguish between Compton-thick absorption, intrinsically weak accretion, and dense gas cocoon scenarios.
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Unification models of Active Galactic Nuclei
Overview chapter summarizing traditional orientation-based and radiation-regulated unification models for AGN, including evolutionary aspects and changing-look AGN.