JADES -- The Rosetta Stone of JWST-discovered AGN: deciphering the intriguing nature of early AGN

Abstract

JWST has discovered a large population of Active Galactic Nuclei (AGN) at high redshift. Many of these newly discovered AGN have broad permitted lines (typically H$\alpha$), but are extremely weak in the X-rays. Here we present the NIRSpec spectrum of the most extreme of these objects, GN-28074, an AGN at $z=2.26$ with prominent Balmer, Paschen and \HeI broad lines, and with the highest limit on the bolometric to X-ray luminosity ratio among all spectroscopically confirmed AGN in GOODS. This source is also characterized by a mid-IR excess, most likely associated with the AGN torus' hot dust. The high bolometric luminosity and moderate redshift of this AGN allow us to explore its properties more in depth relative to other JWST-discovered AGN. The NIRSpec spectrum reveals prominent, slightly blueshifted absorption of H$\alpha$, H$\beta$ and \HeI$\lambda$10830. The Balmer absorption lines require gas with densities of $n_{\mathrm{H}}>10^8{\mathrm{cm}}^{-3}$, inconsistent with an ISM origin, but fully consistent with clouds in the Broad Line Region (BLR). This finding suggests that at least part of the X-ray weakness is due to high (Compton thick) X-ray absorption by (dust-free) clouds in the BLR, or in its outer, slowly outflowing regions. GN-28074 is also extremely radio-weak. The radio weakness can also be explained in terms of absorption, as the inferred density of the clouds responsible for H$\alpha$ absorption makes them optically thick to radio emission through free-free absorption. Alternatively, in this and other JWST-discovered AGN, the nuclear magnetic field may have not developed properly yet, resulting both in intrinsically weak radio emission and also lack of hot corona, hence intrinsic X-ray weakness. Finally, we show that recently proposed scenarios, invoking hyper-dense and ultra-metal-poor outflows or Raman scattering to explain the broad H$\alpha$, are completely ruled out.

21 pages 8 figures in main text. Accepted by MNRAS, updated to accepted version

References in corpus (58)

• The Host Galaxies and Classification of Active Galactic Nuclei
• First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring
• 3D-HST+CANDELS: The Evolution of the Galaxy Size-Mass Distribution since $z=3$
• The MAPPINGS III Library of Fast Radiative Shock Models
• PyNeb: a new tool for analyzing emission lines. I. Code description and validation of results
• Kiloparsec-scale outflows are prevalent among luminous AGN: outflows and feedback in the context of the overall AGN population
• Piecing Together the X-ray Background: Bolometric Corrections for Active Galactic Nuclei
• JADES NIRSpec Spectroscopy of GN-z11: Lyman-$\alpha$ emission and possible enhanced nitrogen abundance in a $z=10.60$ luminous galaxy
• Modelling the nebular emission from primeval to present-day star-forming galaxies
• The SCUBA-2 Cosmology Legacy Survey: 850um maps, catalogues and number counts
• New fully empirical calibrations of strong-line metallicity indicators in star forming galaxies
• GA-NIFS: A massive black hole in a low-metallicity AGN at $z\sim 5.55$ revealed by JWST/NIRSpec IFS
• Deriving model-based T${}_e$-consistent chemical abundances in ionised gaseous nebulae
• Fitting AGN/galaxy X-ray-to-radio SEDs with CIGALE and improvement of the code
• Ionized outflows from active galactic nuclei as the essential elements of feedback
• Black-Hole Mass and Growth Rate at High Redshift
• Ionized outflows in local luminous AGN: what are the real densities and outflow rates?
• The Near-Infrared Broad Emission Line Region of Active Galactic Nuclei -- I. The Observations
• RUBIES: Evolved Stellar Populations with Extended Formation Histories at $z\sim 7-8$ in Candidate Massive Galaxies Identified with JWST/NIRSpec
• JWST UNCOVER: Extremely red and compact object at$z_{\mathrm{phot}}\simeq 7.6$ triply imaged by Abell 2744
• Overview of the JWST Advanced Deep Extragalactic Survey (JADES)
• BAT AGN Spectroscopic Survey - IV: Near-Infrared Coronal Lines, Hidden Broad Lines, and Correlation with Hard X-ray Emission
• A dusty compact object bridging galaxies and quasars at cosmic dawn
• AGN Selection and Demographics: A New Age with JWST/MIRI
• AGN-driven outflows and the AGN feedback efficiency in young radio galaxies
• Chemical abundances of Seyfert 2 AGNs-III. Reducing the oxygen abundance discrepancy
• State-of-the-art AGN SEDs for Photoionization Models: BLR Predictions Confront the Observations
• Probing Star Formation at Low Metallicity: The Radio Emission of Super Star Clusters in SBS0335-052
• The Mass Scale of High-Redshift Galaxies: Virial Mass Estimates Calibrated with Stellar Dynamical Models from LEGA-C
• A Balmer-line Broad Absorption Line Quasar
• The e-MERLIN Galaxy Evolution Survey (e-MERGE): Overview and Survey Description
• Do Some AGN Lack X-ray Emission?
• The Fundamental Planes of Black Hole Activity for Radio-Loud and Radio-Quiet Quasars
• Detection of a Parsec-Scale Jet in a Radio-Quiet Narrow-Line Seyfert 1 Galaxy with Highly Accreting Supermassive Black Hole
• UNCOVER: Candidate Red Active Galactic Nuclei at 3<z<7 with JWST and ALMA
• On the AGN Nature of Broad Balmer Emission in Four Low-Redshift Metal-Poor Galaxies
• Magnetic-reconnection-heated corona in active galactic nuclei: refined disc-corona model and application to broad-band radiation
• Discovery of H alpha absorption in the unusual broad absorption line quasar SDSS J083942.11+380526.3
• The Rise of Faint, Red AGN at $z>4$: A Sample of Little Red Dots in the JWST Extragalactic Legacy Fields
• Multi-wavelength observations of SDSS J105621.45+313822.1, a broad-line, low-metallicity AGN
• Systematic Broad-band X-ray Study of super-Eddington Accretion onto Supermassive Black Holes. I. X-ray Continuum
• On the Emergence of Thousands of Absorption Lines in the Quasar PG1411+442: A Clumpy High-Column Density Outflow from the Broad Emission-Line Region?
• JADES Data Release 3 -- NIRSpec/MSA spectroscopy for 4,000 galaxies in the GOODS fields
• COSMOS-Web: The over-abundance and physical nature of "little red dots"--Implications for early galaxy and SMBH assembly
• Rayleigh and Raman scattering cross-sections and phase matrices of the ground-state hydrogen atom, and their astrophysical implications
• Identifying AGN's Balmer-Absorptions and stratified NLR kinematics in SDSSJ112611.63+425246.4
• JWST meets Chandra: a large population of Compton thick, feedback-free, and intrinsically X-ray weak AGN, with a sprinkle of SNe
• Resolving the nature and putative nebular emission of GS9422: an obscured AGN without exotic stars
• GA-NIFS: An extremely nitrogen-loud and chemically stratified galaxy at $z\sim 5.55$
• A Census of Photometrically Selected Little Red Dots at 4 < z < 9 in JWST Blank Fields
• Stacking X-ray Observations of "Little Red Dots": Implications for their AGN Properties
• Near-infrared Variability Detected in the Young Star-Forming Dwarf Galaxy SBS 0335-052E
• Late-time radio brightening and emergence of a radio jet in the changing-look AGN 1ES 1927+654
• Radiation Pressure Supported Starburst Galaxies & The Fueling of Active Galactic Nuclei
• X-ray View of Little Red Dots: Do They Host Supermassive Black Holes?
• Converting Halpha luminosities into SFRs
• Systematic Collapse of the Accretion Disc Across the Supermassive Black Hole Population
• Evidence for Intrinsic X-ray Weakness Among Red Quasars at Cosmic Noon

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• Mildly Super-Eddington Accretion Onto Slowly-Spinning Black Holes Explains the X-Ray Weakness of the Little Red Dots
• RUBIES: JWST/NIRSpec Confirmation of an Infrared-luminous, Broad-line Little Red Dot with an Ionized Outflow
• A remarkable Ruby: Absorption in dense gas, rather than evolved stars, drives the extreme Balmer break of a Little Red Dot at $z=3.5$
• Little red dots as young supermassive black holes in dense ionized cocoons
• UNCOVER: 404 Error -- Models Not Found for the Triply Imaged Little Red Dot A2744-QSO1
• JADES: comprehensive census of broad-line AGN from Reionization to Cosmic Noon revealed by JWST
• Challenging the AGN scenario for JWST/NIRSpec LRD and non-LRD broad H$\alpha$ emitters in light of non-detection of NIRCam photometric variability and X-ray
• Narrow line AGN selection in CEERS: spectroscopic selection, physical properties, X-ray and radio analysis
• The radio properties of the JWST-discovered AGN
• A direct black hole mass measurement in a Little Red Dot at the Epoch of Reionization
• GA-NIFS: A galaxy-wide outflow in a Compton-thick mini-BAL quasar at z = 3.5 probed in emission and absorption
• Impact of Resonance, Raman, and Thomson Scattering on Hydrogen Line Formation in Little Red Dots
• The warm outer layer of a Little Red Dot as the source of [Fe II] and collisional Balmer lines with scattering wings
• The missing FeII bump in faint JWST AGN: possible evidence for metal-poor broad-line regions at early cosmic times
• Spectral Uniformity of Little Red Dots: A Natural Outcome of Coevolving Seed Black Holes and Nascent Starbursts
• Active galactic nuclei-heated dust revealed in "little red dots"
• A big red dot at cosmic noon
• BASS. XLIX. Characterization of highly luminous and obscured AGNs: local X-ray and [NeV]$\lambda$3426 emission in comparison with the high-redshift Universe
• Connecting the Dots: UV-Bright Companions of Little Red Dots as Lyman-Werner Sources Enabling Direct Collapse Black Hole Formation
• Overmassive black holes in the early Universe can be explained by gas-rich, dark matter-dominated galaxies
• A weak Ly$\alpha$ halo for an extremely bright Little Red Dot: Indications of enshrouded SMBH growth
• JADES Dark Horse: demonstrating high-multiplex observations with JWST/NIRSpec dense-shutter spectroscopy in the JADES Origins Field
• The Cliff: A Metal-Poor Little Red Dot Hosting an Overmassive Black Hole at $z=3.55$
• Little Red Dots as Hidden Neutrino Sources
• Discovery of low-redshift analogues to "Little Red Dots" in DESI: A later evolutionary stage of compact LRDs?
• Mass and Spin Growth of Very Massive Stars in Star Clusters Potentially Associated with Little Red Dots
• When Stars Mimic Monsters: Spectral Evidence for an $\eta$ Carinae-like Giant Eruption in SBS 0335$-$052 E
• The Structure and Evolution of LRDs: Insights from JWST NIRSpec Medium and High Resolution Spectroscopy at $z\sim 4$