REVIEW 7 cited by
Weakness of X-rays and Variability in High-redshift AGNs with Super-Eddington Accretion
Not yet reviewed by Pith; the record is open.
This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.
SPECIMEN: schema-true, not a live event
T0 review · schema-true
One-sentence machine reading of the paper's core claim.
pith:XXXXXXXX · record.json · timestamp
abstract
The James Webb Space Telescope (JWST) observations enable the exploration of active galactic nuclei (AGNs) with broad-line emission in the early universe. Despite their clear radiative and morphological signatures of AGNs in rest-frame optical bands, complementary evidence of AGN activity - such as X-ray emission and UV/optical variability - remains rarely detected. The weakness of X-rays and variability in these broad-line emitters challenges the conventional AGN paradigm, indicating that the accretion processes or environments around the central black holes (BHs) differ from those of low-redshift counterparts. In this work, we study the radiation spectra of super-Eddington accretion disks enveloped by high-density coronae. Radiation-driven outflows from the disk transport mass to the poles, resulting in moderately optically-thick, warm coronae formed through effective inverse Comptonization. This mechanism leads to softer X-ray spectra and larger bolometric correction factors for X-rays compared to typical AGNs, while being consistent with those of JWST AGNs and low-redshift super-Eddington accreting AGNs. In this scenario, UV/optical variability is suppressed due to photon trapping within super-Eddington disks, while X-ray emissions remain weak yet exhibit significant relative variability. These characteristics are particularly evident in high-redshift AGNs powered by lower-mass BHs with $\lesssim 10^{7-8}~M_\odot$, which undergo rapid mass accretion following overmassive evolutionary tracks relative to the BH-to-stellar mass correlation in the local universe.
Forward citations
Cited by 7 Pith papers
-
The Cosmic Rush Hour: Rapid Formation of Bright, Massive, Disky, Star-Forming Galaxies as Signatures of Early-Universe Physics
Early dark energy in large hydrodynamic simulations reproduces JWST's excess of bright, massive, high-redshift galaxies while preserving low-redshift Lambda-CDM behavior.
-
The $z=7.08$ quasar ULAS J1120+0641 May Never Reach a "Normal" Black Hole to Stellar Mass Ratio
The z=7.08 quasar J1120+0641 sits in an overdense environment, yet the available mass around it is probably insufficient for its host galaxy to reach the local black hole to stellar mass relation by z=0.
-
Measurements of the z=4-10 X-ray Luminosity Function: the high space density of moderate-luminosity, obscured AGN
A 32-source X-ray sample yields a z=4-10 AGN luminosity function that is up to two orders of magnitude above model extrapolations at z=7-10.
-
An (in)complete NIRSpec census of Balmer absorption in Type 1 AGN -- radiation-driven outflows in little red dots, quasars and variable stars
About 44% of little red dots have hydrogen-alpha absorption from outflowing gas, implying radiatively driven outflows rather than static atmospheres.
-
The WISSH quasar project. XII. X-ray view of the most luminous quasi-stellar objects at Cosmic Noon
Complete X-ray coverage of 85 hyper-luminous quasars at z≈2-4 shows one-third are X-ray weak and X-ray luminosity is highly dispersed relative to UV and infrared luminosities.
-
Do Little Red Dots Vary?
Super-Eddington accretion models can explain why little red dots show almost no variability, whereas standard sub-Eddington AGN variability models predict changes that should already have been seen.
-
Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). XXIV. 54 New Quasars and Candidate Obscured Quasars at $5.71 \le z \le 7.02$
Spectroscopic follow-up of the completed HSC-SSP survey yields 43 new quasars, 11 candidate obscured quasars, and 29 galaxies at z 5.71 to 7.02.
Discussion (0). Sign in to comment.